C. K. Yeung, MD

At the site of a neuromuscular junction involving smooth muscle erectile dysfunction drugs philippines order sildenafila canada, the axon lies in a shallow groove on the muscle surface impotence is a horrifying thing buy sildenafila 25 mg, and the Schwann cell is retracted to expose the axolemma erectile dysfunction levitra order 100 mg sildenafila mastercard. To produce a region of complete anesthesia on the trunk what causes erectile dysfunction treatment 50 mg sildenafila buy overnight delivery, at least three segments of the spinal cord have to be damaged (see p herbal erectile dysfunction pills nz buy sildenafila 25 mg without prescription. When contiguous spinal nerves are sectioned, the area of tactile loss is always greater than the area of loss of painful and thermal sensations. The biceps brachii tendon reflex involves C5-C6 segments of the spinal cord (see p. The patellar tendon reflex (knee jerk) involves the L2-L4 segments of the spinal cord. A tumor pressing on the 51-52 segments of the spinal cord is likely to interfere with the ankle jerk. The T10 dermatome includes the skin of the umbilicus; the T8 7 motor efferent fibers innervate the intrafusal fibers of a muscle spindle. In voluntary muscle movement, when a prime mover contracts, the antagonistic muscles are inhibited (see p. When a muscle begins to contract, the smaller motor units are stimulated dermatome involves the skin between the xiphoid process and the umbilicus. The L5 dermatome lies over the anterior and lateral surfaces of the leg below the knee. The 52 dermatome extends down the middle of the posterior surface of the thigh and leg. A motor unit consists of a motor neuron in the anterior gray column (horn) of the spinal cord and all the muscle fibers it supplies. In the small muscles of the hand, one nerve fiber supplies only a few muscle fibers. Muscle fatigue is caused by reduced adenosine triphosphate within the muscle fibers. To paralyze a muscle completely, destroying several adjacent segments of the spinal cord or their nerve roots is usually necessary. In the standing position, the line of gravity passes through the odontoid process of the axis, behind the centers of the hip joints, and in front of the knee and ankle joints (see p. A particular posture can often be maintained for long periods by different groups of muscle fibers in a muscle contracting in relays. The cerebral cortex makes an important contribution to the maintenance of normal posture (see p. Muscle wasting can occur if only the efferent motor nerve fibers to a muscle are sectioned (see p. Muscle contracture is a condition in which the muscle contracts and undergoes permanent shortening; it occurs frequently in muscles that normally oppose paralyzed muscles. Muscle fasciculation is seen with chronic disease that affects anterior horn cells or the motor nuclei of cranial nerves. Wasting occurs in the muscles acting on the shoulder joint in patients with painful pericapsulitis involving that joint. On initial evaluation in the emergency department after he regains conscious- ness, he is found to have signs and symptoms of severe neurologic deficits in the upper and lower extremities. A lateral radiograph ofthe cervical region ofthe spine shows fragmentation of the body of the fourth cervical vertebra with backward displacement of a large bony fragment on the left side. After stabilization of the vertebral column by using skeletal traction to prevent further neurologic damage, a complete examination reveals that the patient has signs and symptoms indicating incomplete hemisection of the spinal cord on the left side. Any medical personnel involved in the evaluation and treatment of a patient with spinal cord injuries must know the structure of the spinal cord and the arrangement and functions of the various nerve tracts passing up and down this vital conduit in the central nervous system. Because ofthe devastating nature ofspinal cord injuries and the prolonged disability that results, all concerned with the care of such patients must be trained to prevent any additional cord injury and provide the best chance for recovery. All medical personnel must have a clear picture of the extent of the cord lesion and the possible expecta- tions for the return of function. Spinal cord injuries are common and can occur as a result of automobile and motorcycle accidents, falls, sports injuries, and gunshot wounds. Spinal cord and spinal nerve damage may also be associated with vertebral fractures; vertebral infections; vertebral tumors, radiologic evidence of bone injury with segmental levels of the spinal cord. The close relationship of the spinal cord to the bony vertebral column necessitates a brief review of the vertebral column before the spinal cord is considered. The student must learn the course and connections of the various tracts within the spinal cord in order to be able to diagnose and understand the treatment of cord injuries. It supports the skull, pectoral girdle, upper limbs, and thoracic cage and, by way of the pelvic girdle, transmits body weight to the lower limbs. Within its cavity lie the spinal cord, spinal nerve roots, and the covering meninges, to which the vertebral column gives great protection. Because it is segmented and made up of vertebrae, joints, and pads of fibrocartilage called intervertebral discs, it is a flexible structure. A typical vertebra consists of a rounded body anteriorly and a vertebral arch posteriorly. These enclose a space called the vertebral foramen, through which run the spinal cord and its coverings. The vertebral arch consists of a pair of cylindrical pedicles, which form the sides of the arch, and a pair of flattened laminae, which complete the arch posteriorly. The vertebral arch gives rise to seven processes: one spinous, two transverse, and four articular. The spinous process, or spine, is directed posteriorly from the junction of the two laminae. The transverse processes are directed laterally from the junction of the laminae and the pedicles. Both the spinous and transverse processes serve as levers and receive attachments of muscles and ligaments. The surface marking of the external occipital protuberance of the skull, the ligamentum nuchae (solid black line) and some important palpable spines (solid dots) are also shown. The articular processes are vertically arranged and consist of two superior and two inferior processes. The two superior articular processes of one vertebral arch articulate with the two inferior articular processes of the arch above, forming two synovial joints. The pedicles are notched on their upper and lower borders, forming the superior and inferior vertebral notches. On each side, the superior notch of one vertebra and the inferior notch of an adjacent vertebra together form an intervertebral foramen. Joint betwee n articular processes (synovial) Joint between bodies (cartilaginou s and synovial) Cervical Arachnoid mater Cauda equina Superior articular p rocess. B: Third lumbar vertebra seen from above showing the relationship between intervertebral disc and cauda equina. The anterior and posterior nerve roots of a spinal nerve unite within these foramina with their coverings of dura to form the segmental spinal nerves. Sandwiched between the vertebral bodies is an inter- vertebral disc of fibrocartilage. Intervertebral Discs Below the axis, the vertebrae articulate with each other by means of cartilaginous joints between their bodies and by synovial joints between their articular processes. The intervertebral discs are thickest in the cervical and lumbar regions, where the movements of the vertebral column are greatest. They serve as shock absorbers when the load on the vertebral column is suddenly mebooksfree. Each disc consists of a peripheral part, the annulus fibrosus, and a central part, the nucleus pulposus. The annulus fibrosus is composed of fibrocartilage, which is strongly attached to the vertebral bodies and the anterior and posterior longitudinal ligaments of the vertebral column. It is normally under pressure and situated slightly nearer to the posterior than to the anterior margin of the disc. The upper and lower surfaces of the bodies of adjacent vertebrae that abut onto the disc are covered with thin plates of hyaline cartilage. The semifluid nature of the nucleus pulposus allows it to change shape and permits one vertebra to rock forward or backward on another. A sudden increase in the compression load on the vertebral column flattens the nucleus pulposus, which is accommodated by the resilience of the surrounding annulus fibrosus. Sometimes, the outward thrust is too great for the annulus fibrosus and it ruptures, allowing the nucleus pulposus to herniate and protrude into the vertebral canal, where it may press on the spinal nerve roots, the spinal nerve, or even the spinal cord. With advancing age, the nucleus pulposus becomes smaller and is replaced by fibrocartilage. The collagen fibers of the annulus degenerate, and, as a result, the surfaces of the vertebral column from the skull to the sacrum. The anterior ligament is wide and is strongly attached to the front and sides of the vertebral bodies and to the intervertebral discs. The posterior ligament is weak and narrow and is attached to the posterior borders of the discs. The joints between two vertebral arches consist of synovial joints between the superior and inferior articular processes of adjacent vertebrae. In the cervical region, the supraspinous and interspinous ligaments are greatly thickened to form the strong ligamentum nuchae. In old age, the discs are thin and less elastic, and distinguishing the nucleus from the annulus is no longer possible. Ligamen ts the anterior and posterior longitudinal ligaments run as continuous bands down the anterior and posterior the joints between the vertebral bodies are innervated by the small meningeal branches of each spinal nerve. The joints between the articular processes are innervated by branches from the posterior rami of the spinal nerves; the joints of any particular level receive nerve fibers from two adjacent spinal nerves. The atlanto-occipital joints and the atlanto-aXial joints should be reviewed in a textbook of gross anatomy. At any particular vertebral level, the joints receive nerve fibers from two adjacent spinal nerves. It begins superiorly at the foramen magnum in the skull, where it is continuous with the medulla oblongata of the brain, and it terminates inferiorly in the adult at the level of the lower border of the first lumbar vertebra. In the young child, it is relatively longer and usually ends at the upper border of the third lumbar vertebra. Thus, it occupies the upper two thirds of the vertebral canal of the vertebral column and is surrounded by the three meninges, the dura mater, the arachnoid mater, and the pia mater. In the cervical region, where it gives origin to the brachial plexus, and in the lower thoracic and lumbar regions, where it gives origin to the lumbosacral plexus, the spinal cord is fusiformly enlarged; the enlargements are referred to as the cervical and lumbar enlargements. B: Three segments of the spinal cord showing the coverings of dura mater, arachnoid mater, and pia mater. The cord possesses a deep longitudinal fissure called the anterior median fissure in the midline anteriorly and a shallow furrow called the posterior median sulcus on the posterior surface. Each root is attached to the cord by a series of rootlets, which extend the whole length of the corresponding segment of the cord. Each posterior nerve root possesses a posterior root ganglion, the cells of which give rise to peripheral and central nerve fibers. Spinal Cord Structure the spinal cord is composed of an inner core of gray matter, which is surrounded by an outer covering of white matter. Substantia gelatinosa, nucleus proprius, nucleus dorsalis (Clarke column) at L1-L4, and visceral afferent nucleus present Present; gives rise Medial group of cells for trunk muscles (Tl-T6) and to preganglionic fasciculus gracilis present Lumbar sympathetic fibers Present (Ll-L2 [3]); gives rise to Round to oval Fasciculus cuneatus absent; fasciculus gracilis present Medial group of cells for lower limb muscles; central group of cells for lumbosacral nerve preganglionic sympathetic fibers Sacral Round Small amount; fasciculus cuneatus Medial group of cells for lower limb and perineal muscles Substantia gelatinosa and nucleus proprius present Absent; group of cells present at 82-54, absent; fasciculus gracilis present for parasympathetic outflow aThe information in this table is useful for identifying the specific level of the spinal cord from which a section has been taken. For a comparison of the structural details in different regions of the spinal cord, see Table 4-1. On cross section, the gray matter is seen as an H-shaped pillar with anterior and posterior gray columns, or horns, united by a thin gray commissure containing the small central canal. A small lateral gray column or horn is present in the thoracic and upper lumbar segments of the cord. The amount of gray matter present at any given level of the spinal cord is related to the amount of muscle innervated at that level. Thus, its size is greatest within the cervical and lumbosacral enlargements of the cord, which innervate the muscles of the upper and lower limbs, respectively. The nerve cells are multipolar, and the neuroglia forms an intricate network around the nerve cell bodies and their neurites. The smaller nerve cells are also multipolar, and the axons of many of these pass out in the anterior roots of the spinal nerves as y efferents, which innervate the intrafusal muscle fibers of neuromuscular spindles. For practical purposes, the nerve cells of the anterior gray column can be divided into three basic groups or columns: medial, central, and lateral. The medial group is present in most segments of the spinal cord and is responsible for innervating the skeletal muscles of the neck and trunk, including the intercostal and abdominal musculature. The central group is the smallest and is present in some cervical and lumbosacral segments. In the cervical part of the cord, some of these nerve cells (segments C3-C5) specifically innervate the diaphragm and are collectively referred to as the phrenic nucleus. In the upper five or six cervical segments, some of the nerve cells innervate the sternocleidomastoid and trapezius muscles and are referred to as the accessory nucleus. The lumbosacral nucleus present in the second lumbar down to the first sacral segment of the cord is made up of nerve cells whose axons have an unknown distribution. The lateral group is present in the cervical and lumbosacral segments of the cord and is responsible for mebooksfree. The substantia gelatinosa group is situated at the apex of the posterior gray column throughout the length of the spinal cord. Pain and temperature inputs are thought to be modified by excitatory or inhibitory information from other sensory inputs and by information from the cerebral cortex.

The sinus drains posteriorly into the superior and inferior petrosal sinuses and inferiorly into the pterygoid venous plexus erectile dysfunction doctors raleigh nc purchase sildenafila overnight delivery. The two sinuses communicate with each other by means of the anterior and posterior intercavernous sinuses erectile dysfunction diet sildenafila 50 mg purchase visa, which run in the diaphragma sellae anterior and posterior to the stalk of the hypophysis cerebri impotence natural food sildenafila 25 mg buy low cost. Each sinus has an important communication with the facial vein through the superior ophthalmic vein erectile dysfunction johnson city tn buy sildenafila 25 mg amex. Each superior sinus drains the cavernous sinus into the transverse sinus impotence homeopathy treatment discount 100 mg sildenafila with amex, and each inferior sinus drains the cavernous sinus into the internal jugular veln. The outer and inner surfaces of the arachnoid are covered with flattened mesothelial cells. The cisterna cerebellomedullaris lies between the inferior surface of the cerebellum and the roof of the fourth ventricle. All the cisternae are in free communication with one another It escapes from the ventricular system of the brain through the three foramina in the roof of the fourth ventricle and so enters the subarachnoid space. It now circulates both upward over the surfaces of the cerebral hemispheres and downward around the spinal cord. The spinal subarachnoid space extends down as far as the second sacral vertebra (see pp. Eventually, the fluid enters the bloodstream by passing into the arachnoid villi and diffusing through their walls. Pia Mater the pia mater is a vascular membrane covered by flattened mesothelial cells. It closely invests the brain, covering the gyri and descending into the deepest sulci. The cerebral arteries entering the substance of the brain carry a sheath of pia with them. The pia mater forms the tela choroidea of the roof of the third and fourth ventricles of the brain, and it fuses and with the remainder of the subarachnoid space. In certain areas, the arachnoid projects into the venous sinuses to form arachnoid villi. The arachnoid is connected to the pia mater across the fluid-filled subarachnoid space by delicate strands of fibrous tissue. Structures passing to and from the brain to the skull or its foramina must pass through the subarachnoid space. The arachnoid fuses with the epineurium of the nerves at their point of exit from the skull. In the case of the optic nerve, the arachnoid forms a sheath for the nerve, which extends into with the ependyma to form the choroid plexuses in the lateral, third, and fourth ventricles of the brain. Dura Mater the dura mater is a dense, strong, fibrous membrane the orbital cavity through the optic canal and fuses with the sclera of the eyeball. Thus, the subarachnoid space extends around the optic nerve as far as the eyeball. Note the extension of the subarachnoid space around the optic nerve to the eyeball. It is continuous above through the foramen magnum with the meningeal layer of dura covering the brain. The dural sheath lies loosely in the vertebral canal and is separated from the wall of the canal by the extradural space. The dura mater extends along each nerve root and becomes continuous with the connective tissue surrounding each spinal nerve (epineurium). The arachnoid mater is continuous above through the foramen magnum with the arachnoid covering the brain. The arachnoid mater continues along the spinal nerve roots, forming small lateral extensions of the subarachnoid space. The pia mater extends along each nerve root and becomes continuous with the connective tissue surrounding each spinal nerve. Arachnoid Mater the arachnoid mater is a delicate impermeable membrane that covers the spinal cord and lies between the pia mater internally and dura mater externally. The greater part of the occipital bone has been removed, exposing the periosteal layer of dura. On the right side, a window has been made in the dura below the transverse venous sinus to expose the cerebellum and the medulla oblongata in the posterior cranial fossa. In the neck, the dura anol arachnoid have been incised in the midline to expose the spinal cord and rootlets of the cervical spinal nerves. Note the cervical spinal nerves leaving the vertebral canal enveloped in a meningeal sheath. The meningeal sheath has been incised and reflected laterally, exposing the subarachnoid space, the lower end of the spinal cord, and the cauda equina. Note the filum terminale surrounded by the anterior and posterior nerve roots of the lumbar anol sacral spinal nerves forming the cauda equina. The outermost covering, the dura mater, by virtue of its toughness, serves to protect the underlying nervous tissue. The dura protects the cranial nerves by forming a sheath that covers each cranial nerve for a short distance as it passes through foramina in the skull. The pia mater is a vascular membrane that closely invests and supports the brain and spinal cord. In lateral movements, the lateral surface excessive movements of the brain within the skull. The arachnoid mater is a much thinner impermeable membrane that loosely covers the brain. The interval of one hemisphere hits the side of the skull and the medial surface of the opposite hemisphere hits the side of the falX cerebri. In superior movements, the superior surfaces of the cerebral hemispheres hit the vault of the skull, and the mebooksfree. Movements of the brain relative to the skull and dural septa may seriously injure the cranial nerves that are tethered as they pass through the various foramina. Furthermore, the fragile cortical veins that drain into the dural sinuses may be torn, resulting in severe subdural or subarachnoid hemorrhage. Intracranial Hemorrhage in the Infant Intracranial hemorrhage may occur during birth and may result from excessive molding of the head. Excessive anteroposterior compression of the head often tears the anterior attachment of the falx cerebri from the tentorium cerebelli. Bleeding then takes place from the great cerebral veins, the straight sinus, or the inferior sagittal sinus. Intracranial Hemorrhage Excessive brain movement or other cranial trauma can put significant traction on the cranial vessels, leading to rupture and hemorrhage. Intracranial hemorrhage is described based on its relationship to the adjacent layers of the meninges: epidural, subdural, and subarachnoid. Headache the brain itself is insensitive to pain; therefore, headaches are due to the stimulation of receptors outside the brain. The most common artery to be damaged is the anterior division of the middle meningeal artery. A comparatively minor blow to the side of the head, resulting in fracture of the skull in the region of the anterior-inferior portion of the parietal bone, may sever the artery. Arterial or venous injury is especially liable to occur if the vessels enter a bony canal in this region. Bleeding occurs and strips up the meningeal layer of dura from the internal surface of the skull. The intracranial pressure rises and the enlarging blood clot exerts local pressure on the underlying motor area in the precentral gyrus. Blood also passes laterally through the fracture line to form a soft swelling under the temporalis muscle. The burr hole through the skull wall should be placed about 11/2 in (4 cm) above the midpoint of the zygomatic arch. The dura mater receives its sensory nerve supply from the trigeminal and the first three cervical nerves. The dura above the tentorium is innervated by the trigeminal nerve, and the headache is referred to the forehead and face. The dura below the tentorium is innervated by the cervical nerves, and the headache is referred to the back of the head and neck. Meningitis, or inflammation of the meninges, causes severe headache over the entire head and back of the neck. An expanding tumor with its associated raised intracranial pressure produces severe, continuous, and progressive headache caused by the irritation and stretching of the dura. A tumor above the tentorium tends to produce a headache referred to the front of the head, while a tumor below the tentorium produces a headache referred to the back of the head. Subdural hemorrhage results from tearing of the superior cerebral veins at their point of entrance into the superior sagittal sinus. The cause is usually a blow on the front or the back of the head, causing excessive anteroposterior displacement of the brain within the skull. Migraine is a common form of headache, which may be unilateral or bilateral, recurring at intervals and associated with prodromal visual disturbances. The prodromal visual disturbances are thought to be due to sympathetic vasocon- striction of the cerebral arteries supplying the visual cortex. The headache is chiefly due to the dilation and stretching of other cerebral arteries and branches of the external carotid artery. In an epidural hemorrhage, the blood strips up the meningeal layer of the dura from the endosteal layer of dura (periosteum of the skull), producing a lensshaped hyperdense collection of blood that compresses the brain and displaces the midline structures to the opposite side. The shape of the blood clot is determined by the adherence of the meningeal layer of dura to the periosteal layer of dura. In patients with subdural hematoma, the blood accumulates in the extensive potential space between the meningeal layer of dura and the arachnoid, producing a long crescent-shaped, hyperdense rim of blood that extends from anterior to posterior along the inner surface of the skull. With a large hematoma, the brain sulci are obliterated and the midline structures are displaced to the opposite side. The pain is referred to the skin of the face and the forehead along the branches of the trigeminal nerve. Tonic spasm of the ciliary muscle of the eye, when attempting to focus on an object for prolonged periods. This commonly occurs in individuals who need lenses for the correction of presbyopia. The hematoma is lens shaped and occupies the space between the endosteal layer of dura (periosteum of the skull) and the meningeal layer of dura (true dura, hence the name epidural). B: Subdural hemorrhage from the cerebral veins at the site of entrance into the venous sinus on the right side. The hematoma is crescent shaped and occupies the space between the meningeal layer of dura and the arachnoid. The superior sagittal sinus, straight sinus, and occipital sinus come together at the confluence of sinuses, which then drains laterally into two transverse sinuses. The sigmoid sinuses are a direct continuation of the transverse sinuses and eventually eXit the cranial cavity through the jugular foramen, at this point becoming the internal jugular vein. The endosteal layer is essentially the periosteum of the skull and therefore not present in the vertebral canal. The vasculature for the central nervous system is located in the subarachnoid space. Spinal Cord Meninges the dura mater of the spinal cord is continuous with the meningeal layer of the cranial dura. The arachnoid mater is continuous with cranial arachnoid mater and maintains the same meningeal relationships in the vertebral canal as the cranial cavity. The pia mater closely covers the spinal cord and has multiple thickenings on either side, called denticulate ligaments, that form a means of suspension for the spinal cord in the dural sheath. Which blood vessels are damaged more commonly, the cerebral arteries or the cerebral veins If so, which ones are damaged most commonly and what is the reason for their increased susceptibility While performing an autopsy on a patient who had died of a meningioma, the pathologist explains to a group of students that these tumors arise from the arachnoid mater. She explains that they occur in those areas in which the arachnoid pierces the dura to form the arachnoid villi that project into the dural venous sinuses. A 10-year-old girl is admitted to hospital for surgical correction of medial strabismus of the right eye. Twenty-four hours after successful completion of the operation, her right eyeball is noted to project forward excessively (proptosis) and the conjunctiva of the right eye is inflamed. The ophthalmologist is greatly concerned because he does not want the complication of cavernous sinus thrombosis to occur. What is the connection between infection of the eye and cavernous sinus thrombosis On examination, a 41-year-old man is found to have paralysis of the lateral rectus muscle of his left eye; the left pupil is dilated but reacts slowly to light, and anesthesia of the skin over the left side of the forehead is noted. A carotid arteriogram reveals the presence of an aneurysm of the right internal carotid artery situated in the cavernous sinus. Using your knowledge of anatomy, explain the clinical findings on physical examination. On ophthalmoscopic examination, a 45-year-old woman is found to have edema of both optic discs (bilateral papilledema) and congestion of the retinal veins. He notes that the child has perfectly normal use of his arms but that his legs are stiff; and when he walks, he tends to cross his legs and has a scissorlike gait. Using your knowledge of anatomy, explain what happens to the fetal skull bones during delivery. Why is cerebral hemorrhage more likely to occur in a premature baby with a malpresentation A 25-year-old woman is admitted to the emergency department unconscious after being hit on the side of the head by a car while crossing the road. On examination, she is found to have a large, doughlike swelling over the right temporalis muscle. A lateral radiograph of the skull shows a fracture line across the groove for the anterior division of the right middle meningeal artery.

These cytolysins are also potent agents for triggering inflammation by attracting neutrophils and macrophages erectile dysfunction drugs from himalaya order sildenafila. First erectile dysfunction injection test generic sildenafila 50 mg on line, lung congestion due to production of cytolysins could have caused breathing difficulties erectile dysfunction 70 year olds cheap sildenafila 75 mg with mastercard, resulting in death young and have erectile dysfunction buy line sildenafila. Second and more likely erectile dysfunction at age 29 discount sildenafila 75 mg otc, the production of the superantigen would result in that toxin gaining access to the bloodstream, causing superantigenicity, leading to cytokine production with consequent hypotension, shock, and death. Thus, these children acquired their infections from the community rather than from hospitalized patients. Rifampin penetrates lung mucosal tissues extensively whereas vancomycin penetrates 25 to 50%. Clindamycin or linezolid should be considered to reduce production of exotoxins including superantigens, Panton-Valentine leukocidin, and -toxin (in addition to their antimicrobial effects). That suggests the infecting strain was probably acquired as a result of the surgery. It is thought that there may be a local effect of the superantigen that reduces inflammation at the site of infection. It activates a subclass of T cells that, as a result, may undergo apoptosis or trigger immune activation with the release of a cascade of cytokines. Resistance to all the semisynthetic antistaphylococcal penicillins (methicillin, oxacillin, nafcillin, and cloxacillin) results from alteration of the bacterial target of these antibiotics. The factors that contributed to pneumonia rather than continued asymptomatic carriage were his smoking and his recent viral infection. Both factors impede the clearance of inhaled particles by the mucociliary escalator, and both adversely affect the phagocytic function of alveolar macrophages. If the infection is very dense, the use of a rapidly bactericidal antibiotic can lead to the release of cell wall fragments that may increase the inflammatory response in the lungs. Antibiotic resistance is also a possible explanation for a poor response to therapy; however, that would be more likely if the patient had been treated with a penicillin or a macrolide, antibiotics to which resistance has emerged over the past few decades. Immunization provides the patient with type-specific antibodies against the 23 most common serotypes of pneumococcal capsule. With the influx of polymorphonuclear leukocytes into the alveoli, the bacteria would be rapidly ingested and killed, stopping the spread of infection. Antibiotic treatment also prevents the development of the rare local suppurative complications. Unlike a direct infection of the skin, such as cellulitis, this rash is caused by secreted streptococcal pyrogenic exotoxins (SpeA-C) that circulate in the bloodstream. The clinical signs and symptoms of strep throat may resolve shortly after initiation of antibiotic therapy. Several studies, however, have demonstrated that courses of penicillin shorter than 10 days are not enough to eradicate the organisms and to prevent an overly vigorous immune response. An injection of long-acting penicillin compounds is an alternative that excludes the possibility of patient, or in the case of V. The presentation could be consistent with either gonococcal or chlamydial infection. Alternatively, a culture for Neisseria gonorrhoeae could be plated at the bedside. A Gram stain is the most rapid diagnostic method, and this was reported in the case description. Spread of microorganisms from the cervix, through the uterus, to the fallopian tubes is most likely to occur at this point in the menstrual cycle because of the less resistant state of the cervical mucus. After repeat cases, enteric bacteria and strict anaerobes may also be secondarily involved. The organism was likely transmitted to him by respiratory droplets, and he became colonized in the nasopharynx. A more rational antibiotic therapy would have decreased the likelihood of abscess formation. It is likely that many intestinal Bacteroidales species synthesize zwitterionic polysaccharides, which contain both positive and negative charges. He was described as having "a rapid heart rate with a feeble pulse and low blood pressure," suggesting that the degree of dehydration was severe enough to affect his hemodynamic status and possibly lead to shock from hypovolemia. This is a rare occurrence in adults with ordinary diarrheal diseases but is common with cholera. This essentially lifts a barrier to passage of viable Vibrio cholerae to the small intestine and lowers the number of organisms that have to be ingested to cause disease. Are all enteric bacteria capable of causing disease, or are some more frequently pathogenic than others Thus, acquisition of infection can always be attributed to a fecal­oral route of transmission. Organisms that are acid sensitive and require very high inocula to establish infection generally require a vehicle such as food or water for transmission. Contamination of food sources or water supplies with raw sewage or animal feces may be to blame. By contrast, organisms that are acid resistant and establish infection at very low inocula can be acquired by direct contact with an infected individual. The intra-abdominal infection resulting from the ruptured appendix followed a typical course. The blood culture was positive for Escherichia coli, and it is likely that an anaerobic blood culture was not ordered, or the Bacteroides fragilis may have been confined to the peritoneal cavity. This permits their transfer to other Bacteroides species and even to species of other genera. Antibiotics that were once effective against Bacteroides, such as clindamycin, are now ineffective in an increasing number of clinical strains. When she presented with the ruptured appendix and colonic organisms were cultured from her peritoneal cavity, broad-spectrum antibiotics, including those active against both the facultative and the strict anaerobes, should have been administered. A drug targeting Bacteroidales species should have been given along with the cephalosporin therapy. Knowing that there was colonic spillage into the peritoneum, she could have been treated with a combination -lactam­-lactamase inhibitor, or a carbapenem like imipenem, or a -lactam plus metronidazole. Pathogens that produce enterotoxins or otherwise disrupt the absorptive function of the intestinal mucosal cells produce secretory diarrhea. Consequently, the principal clinical manifestations are watery, voluminous diarrhea; abdominal cramps; and nausea and vomiting (if the upper intestine or stomach is involved). Pathogens that attach to and invade the mucosa also induce a significant host inflammatory response. Diarrhea from Campylobacter jejuni, for example, a prominent foodborne pathogen around the world, may be as much a consequence of the inflammatory response as it is a consequence of any virulence factors produced by the microbe. Possible additional manifestations of such responses are fever, small stool volumes with mucus or blood, and abdominal pain. The cholera morbidity in South America may not be sufficient to produce this effect. If the patient is in hypovolemic shock or impending shock, or if the patient is vomiting intractably, intravenous rehydration with correction of electrolyte losses may be necessary. However, most diarrheal illnesses, including cholera, can be treated with oral rehydration. Oral rehydration solutions generally contain sodium chloride and a simple sugar or carbohydrate that facilitates absorption via an unaffected pathway that links sodium ion absorption to glucose transport. Another important part of therapy is replacement of lost potassium and bicarbonate, ions that are also components of the World Health Organization rehydration formulation. Because illnesses with watery diarrhea are self-limited, antibiotics are rarely needed or used. From a public perspective, separating the disposal of human and animal feces from sources of food and water disrupts a critical cycle of transmission. In the case of personally transmitted pathogens, such as Shigella species, hand washing may play an important role. Consequently, direct contact with other infants, caregivers, or fomites may be important. Because it is often difficult to control what goes into the mouth of a young child or infant, prevention is a significant challenge. Immunization against enteric diseases is an eventual goal but has not proven practical up to this point, except in the case of typhoid fever (see Chapter 17). The shigellae are human pathogens, and the only significant reservoir is in humans. Shedding of shigellae in the stool may persist for several weeks after acute infection in an untreated individual. However, toddlers, more than any other age group, are likely to put objects into their mouths. Shigellae are ingested most commonly on contaminated fingers or inanimate objects handled by an infected person. Once ingested, the organism can transit the stomach unscathed because of its acid resistance. This accounts for the very low infectious inoculum and the modes of transmission that involve person-to-person spread. They are then released into the lamina propria, where they invade intestinal epithelial cells through their basal surface. The bacteria are able to spread directly from cell to cell and induce a form of cell death called pyroptosis. This process involves the release of inflammatory cytokines that recruit neutrophils and macrophages into the area. Eventually, ulcers in the mucosa form; blood and inflammatory exudates are released into the lumen, accounting for the appearance of the stool. Fluids are necessary because of the mild dehydration and the ongoing water loss associated with high fever. Antibiotics have been shown to reduce the duration of illness and to shorten the carriage state (thus preventing transmission to others after the acute illness resolves). However, resistance to this agent is spreading around the world, and in most other countries, fluoroquinolones are more likely to be active. The gene for this toxin is carried on a bacteriophage on the bacterial chromosome. Profuse bleeding in the colon is caused by the interaction of inflammatory cytokines and shigalike toxins, which damages blood vessels in the lamina propria. Glomerular endothelial cell products (including von Willebrand factor, plasminogen activator inhibitor, prostacyclin, nitric oxide, and others) may mediate local pathophysiology leading to platelet thrombi, the characteristic feature of the disease. Patients with this illness, particular children, should be watched carefully for kidney damage. After a period of growth in these organs, there ensues a persistent and continuous second bacteremia that leads to invasion of the gallbladder and kidney and reinvasion of the gut mucosa, especially at the Peyer patches. First, reinvasion of the gut after the secondary bacteremia may cause more damage than the primary infection. Late in the course of typhoid fever, patients may develop intestinal perforations and fatal peritonitis. Second, invasion of other organs may result in catastrophic damage, including splenic rupture, hepatitis, or glomerulonephritis. Third, invasion of the gallbladder in an individual with stones may lead to a prolonged carrier state, adding to the human reservoir for further transmission. Although it did not play a role in this case, an endotracheal tube or an indwelling catheter in the bladder or a vein increases risk by serving as a portal for infection. Infections in these patients are most often caused by the bacteria with which they are colonized. Patients with severe defects in immunity, such as those induced by malignancies, diabetes, or chemotherapeutic or other immunosuppressive agents are at greatest risk from systemic pseudomonal infections. An endotracheal tube or an indwelling catheter in the bladder or a vein increases risk by serving as a portal for infection. Most Salmonella enteritis is caused by animal species and strains not fully adapted to humans. Salmonella typhi is an exclusively human pathogen and is better adapted to invade and to persist in the human host than are the other salmonellae. The result is typhoid fever, a disease that is not a manifestation of infection with animal salmonellae in humans. Because typhoid fever is caused by an exclusively human pathogen, cases can often be traced back to a human carrier, often a food handler. The animal Salmonella infections are generally associated with foods derived from infected animals, such as poultry, eggs, milk, and meat. These foodstuffs are generally contaminated from the farm, and they cause human infection when they are improperly handled or inadequately cooked. After the organisms penetrate through the intestinal mucosa, they are taken up by macrophages and dendritic cells and Pseudomonas Infection of a Cystic Fibrosis Patient 1. Also, the underlying predisposing condition, cystic 765 fibrosis, is very different from H. The Pseudomonas strains that infect cystic fibrosis patients tend to eventually emerge with distinguishing phenotypes including mucoidy, which promotes chronic colonization. In this case, the organism was probably acquired orally or through aerosolization and may have temporarily colonized the upper airways before descending into the airways. Yes, they help to treat active pneumonia, but they do not fully eliminate the pathogen from the airway. Transmission from patient to patient is thought to occur primarily via the hands of health care workers and by contaminated fomites and surfaces. Yes, ampicillin and cephalosporins are two of the antibiotic groups most often associated with C. To avoid the development of vancomycin-resistant strains of other Gram-positive pathogenic bacteria such as Enterococcus and Staphylococcus. Because spores are not killed by antibiotics, they are probably the means by which C. While the vegetative bacteria present were killed by the antibiotic, some spores remained viable in the intestinal tract and were able to cause a recurrence of infection once the metronidazole treatment was halted. Alternatively, spores that are the infectious form that is transmitted to the patient after antibiotic treatment may have been reintroduced to Mrs.

The cells in the posterior gray horn of the spinal cord are associated with sensory function (see p erectile dysfunction nerve cheap sildenafila 75 mg otc. The lower end of the medulla oblongata is directly continuous with the spinal cord in the foramen magnum erectile dysfunction treatment yahoo order sildenafila 25 mg on-line. The medulla oblongata has a central canal in its lower part that is continuous with that of the spinal cord erectile dysfunction treatment milwaukee purchase sildenafila with visa. The midbrain has a cavity called the cerebral aqueduct erectile dysfunction doctors mcallen texas sildenafila 50 mg purchase on-line, which opens above into the third ventricle smoking and erectile dysfunction statistics discount sildenafila 50 mg buy. The vermis is the name given to that part of the cerebellum joining the cerebellar hemispheres together. The internal capsule is an important collection of ascending and descending nerve fibers, which has the caudate nucleus and the thal- amus on its medial side and the lentiform nucleus on its lateral side. The cerebral hemispheres are separated by a vertical, sagittally placed fibrous septum called the falx cerebri. The tentorium cerebelli is horizontally placed and roofs over the posterior cranial fossa and separates the cerebellum from the occipital lobes of the cerebrum. The lobes of the cerebral hemisphere are named for the skull bones they lie under. The corpus callosum is a mass of white matter lying within each cerebral hemisphere. The cavity present within each cerebral hemisphere is called the lateral ventricle. A spinal nerve is formed by the union of an anterior and a posterior root in an intervertebral foramen. A posterior root ganglion contains the cell bodies of sensory nerve fibers entering the spinal cord. The lateral ventricles communicate indirectly with the fourth ventricle through the interventricular foramen, the third ventricle, and the cerebral aqueduct of the midbrain. Following trauma and sudden movement of the brain within the skull, the large arteries at the base of the brain are rarely torn. The movement of the brain at the time of head injuries may stretch and damage the small delicate 6th cranial nerve (the small 4th cranial nerve may also be injured). The 3rd cervical vertebra lies opposite the 4th cervical spinal cord segment (see Table 1-3, p. The lst lumbar vertebra lies opposite the sacral and coccygeal spinal cord segments. The swelling over the right temporal region and the radiologic finding of a linear fracture over the anterior-inferior angle of the right parietal bone would strongly suggest that the right middle meningeal artery had been damaged and an epidural (extradural) hemorrhage had occurred. Blood had spread through the fracture line into the overlying temporalis muscle and soft tissue. The left-sided paralysis (left hemiple- gia) was due to pressure exerted by the right-sided epidural hemorrhage on the precentral gyrus of the right cerebral hemisphere. In persons in whom the spinal canal was originally small, significant narrowing of the canal in the lumbar region can lead to neurologic compression of the cauda equina with pain radiating to the back, as in this patient. One of the complications of osteoarthritis of the vertebral column is the growth of osteophytes, which commonly encroach on the intervertebral foramina, causing pain along the distribution of the segmental nerve. In this patient, the segmental nerves L4-L5 and 51-53, which form the important sciatic nerve, were involved. This would explain the pain radiating down the left leg and the atrophy of the leg muscles. The first symptoms are involuntary, abrupt, and purposeless movements of the upper limbs associated with clumsiness and dropping things. Associated with these movement defects are memory impairment and loss of intellectual capacity. Huntington disease is an autosomal-dominant disorder with the defect localized to the short arm of chromosome 4. This case is an example of a hereditary disorder that mainly involves a particular group of neurons. The purpose of this chapter is to help students understand how the basic excitable cell-the neuron-communicates with other neurons. It also considers certain injuries to the neuron and the effects of drugs on the mechanism by which neurons communicate with one another. Neurons are excitable cells that are specialized for the reception of stimuli and the conduction of the nerve impulse. They vary considerably in size and shape, but each possesses a cell body from which one or more processes called neurites project. Neurites responsible for receiving information and conducting it toward the cell body are dendrites. The single long tubular neurite that conducts impulses away from the cell body is the axon. Unlike most other cells in the body, normal neurons in the mature individual do not undergo division and replication. Neuron Types Although the cell body of a neuron may be as small as 5 µm or as large as 135 µm in diameter, the processes or neurites may extend over a distance of more than 1 m. Neurons can be classified morphologically based on the number, length, and mode of branching of their neurites. In this type of neuron, the fine terminal branches found at the peripheral end of the axon at the receptor site are often referred to as the dendrites. Bipolar neurons have an elongated cell body, with a single neurite emerging from each end. Examples of this type of neuron are found in the retinal bipolar cells and the cells of the sensory cochlear and vestibular gangha. With the exception of the long process, the axon, the remainder of the neurites are 1 m or more in length in extreme cases. The axons of these neurons form the long fiber tracts of the brain and spinal cord and the nerve fibers of peripheral nerves. The pyramidal cells of the cerebral cortex, the Purkinje cells of the cerebellar cortex, and the motor cells of the spinal cord are good examples. The short dendrites that arise from these neurons give them a star-shaped appearance. These neurons are numerous in the cerebral and cerebellar cortex and are often inhibitory in function. Golgi type I neurons have a long axon that can stretch Interestingly, the volume of cytoplasm within the nerve cell body is often far less than the total volume of cytoplasm in the neurites. Nucleus the nucleus, which stores the genes, is commonly centrally located within the cell body and is typically large and rounded. In mature neurons, the chromosomes no longer duplicate themselves and function only in gene expression. Therefore, the chromosomes are not arranged as compact structures but exist in an uncoiled state. The large size of the nucleolus probably is due to the high rate of protein synthesis, which is necessary to maintain the protein level in the large cytoplasmic volume that is present in the long neurites as well as in the cell body. In the female, one of the two X chromosomes is com- pact and is known as the Barr body. It is composed of sex chromatin and sits at the inner surface of the nuclear envelope. The envelope is double layered and possesses fine nuclear pores, through which materials can diffuse into and out of the nucleus. Therefore, the substance in the nucleus and the cytoplasm can be considered as functionally continuous. Newly formed ribosomal subunits can be passed into the cytoplasm through the nuclear pores. Cytoplasm the cytoplasm is rich in rough (granular) and smooth (agranular) endoplasmic reticulum. Nissl substance consists of granules that are distributed throughout the cytoplasm of the cell body, except for the region close to the axon, called the axon hillock. The granular material also extends into the proximal parts of the dendrites but is not present in the axon. Although many of the ribosomes are attached to the surface of the endoplasmic reticulum, many more lie free in the intervals between the cisternae. The Nissl substance is responsible for synthesizing protein, which flows along the dendrites and the axon and replaces the proteins that are broken down during cellular activity. Fatigue or neuronal damage causes the Nissl substance to move and become concentrated at the periphery of the cytoplasm. This phenomenon, which gives the impression that the Nissl substance has disappeared, is known as chromatolysis. The Golgi complex, when seen with the light microscope after staining with a silver-osmium method, appears as a network of irregular wavy threads around the nucleus. The protein produced by the Nissl substance is transferred to the inside of the Golgi complex in transport mebooksfree. Note the presence of dark-staining Nissl substance in the cytoplasm of four neurons. The inner membrane is thrown into folds or cristae that project into the center of the mitochondrion. Mitochondria possess many enzymes, which are localized chiefly on the inner mitochondrial membrane. These enzymes vesicles, where it is temporarily stored and where carbohydrate may be added to the protein to form glycoproteins. The proteins are believed to travel from one cisterna to another via transport vesicles. Each cisterna of the Golgi complex is specialized for different types of enzymatic reaction. At the trans side of the complex, the macromolecules are packaged in vesicles for transport to the nerve terminals. The Golgi complex is also thought to be active in lysosome production and in the synthesis of cell membranes. Neurofibrils, as seen with the light microscope after staining with silver, are numerous and run parallel to each other through the cell body into the neurites. With the electron microscope, the neurofibrils resolve into bundles of neurofilaments-each filament measuring about 10 nm in diameter. Microfilaments are concentrated at the periphery of the cytoplasm just beneath the plasma membrane where they form a dense network. Together with microtubules, microfilaments play a key role in the formation of new cell processes and the retraction of old ones. They measure about 25 nm in diameter and are found interspersed among the neurofilaments. In the axon, all the microtubules are arranged in parallel, with one end pointing to the cell body and the other end pointing distally away from the cell body. The stop-and-start movement is caused by the periodic dissociation of the organelles from the track or the collision with other structures. Cell transport can take place in both directions in the cell body and its processes. In anterograde (away from the cell) movement, kinesin-coated organelles are thought to move toward one end of the tubule, and, in retrograde (toward the cell) movement, dynein-coated organelles are thought to move toward the other end of the tubule. The direction and speed of the movement of an organelle can be brought about by the activation of one of the motor proteins or of both simultaneously. The molecular motor has not been identified but is probably one of the kinesin families. They serve the cell by acting as intracellular scavengers and contain hydrolytic enzymes. Lysosomes eXist in three forms: (1) primary lysosomes, which have just been formed; (2) secondary lysosomes, which contain partially digested material (myelin figures); and (3) residual bodies, in which the enzymes are inactive and the bodies have evolved from digestible materials such as pigment and lipid. They are associated with the formation of the spindle during cell division and in the formation of microtubules. Centrioles are also found in mature nerve cells, where they are likely involved in the maintenance of microtubules. Lipofuscin (pigment material) occurs as yellowishbrown granules within the cytoplasm. It probably forms as the result of lysosomal activity, and it represents a harmless metabolic byproduct. Melanin granules are found in the cytoplasm of cells in certain parts of the brain. Their presence may be related to the catecholamine-synthesizing ability of these neurons, whose neurotransmitter is dopamine. The membrane is about 8 nm thick, which is too thin to be seen with the light microscope. When viewed under the electron microscope, the plasma membrane appears as two dark lines with a light line between them. The plasma membrane is composed of an inner and an outer layer of very loosely arranged protein molecules, each layer being about 2. The lipid layer is made up of two rows of phospholipid molecules arranged so that their hydrophobic ends are in contact with each other and their polar ends are in contact with the protein layers. Certain protein molecules lie within the phospholipid layer and span the entire width of the lipid layer. These molecules provide the membrane with hydrophilic channels through which inorganic ions may enter and leave the cell. Carbohydrate molecules are attached to the outside of the plasma membrane and are linked to the proteins or the lipids, forming what is known as the cell coat or glycocalyx. The plasma membrane and the cell coat together form a semipermeable membrane that allows diffusion of certain ions through it but restricts others.

Other symptoms include apnea erectile dysfunction treatment in tampa purchase 25 mg sildenafila amex, upper extremity weakness erectile dysfunction medications otc order sildenafila 50 mg mastercard, loss of consciousness icd 9 code erectile dysfunction due diabetes order sildenafila 100 mg otc, and pupillary dilatation impotence quad hoc order generic sildenafila. If the vital signs do not improve erectile dysfunction other names purchase sildenafila in united states online, start using Advanced Cardiovascular Life Support doses of sympathomimetics, especially epinephrine 1mg. Determine with the obstetrician whether an emergency cesarean section is needed to protect the fetus from hypoperfusion. Although local anesthetic cardiotoxicity is a well-known complication of bupivacaine, the patient received about 1. Clot may prevent the clipping action of the superior constrictor muscle on the vessels. Injury: Oral cavity and oropharyngeal structures such as tonsillar pillars, uvula, soft palate, tongue, superior constrictor muscle, or teeth can be injured during tonsillectomy. Edema of tongue, nasopharynx and palate: Need replacement of nasal trumpet and intravenous steroids. Management: If bleeding is not controlled after removal of clot and topical application of dilute adrenaline, hydrogen peroxide and with pressure, then patient is taken to operation room. Approximation of pillars with mattress sutures or external carotid ligation may be required in rare cases. Pulmonary complications: Aspiration of blood, mucus or tissue fragments may lead to atelectasis or lung abscess. Tonsillar remnants: the remaining tonsil tags or tissue may cause repeated infection. But refractory cases may need reconstructive surgery (pharyngeal flap, sphincteroplasty or posterior pharyngeal wall augmentation). Nasopharyngeal stenosis: It occurs due to scarring after excessive damage to nasopharyngeal mucosa (roof, posterior and lateral walls) and resection of posterior tonsillar pillar. If plica triangularis near the lower pole of tonsil is not removed along with tonsil, it may get hypertrophied. Sloughing and severe hemorrhage after accidental suture ligature of lingual and maxillary arteries and pseudoaneurysm and excessive bleeding due to internal carotid artery. Injury to aberrant vessels such as carotid artery arising in fossa of Rosenmuller. Section 8 w operative Procedures and instruments 58 points of Focus ¯ aneStheSia, poSition ¯ proceDureS ¯ poStoperatiVe care ¯ coMpLicationS Endoscopies You fail only when you do not strive sufficiently to manifest infinite power. There are several models of laryngoscopes, which are described in chapter of instruments. The shape and size of viewing and distal ends and body vary with the types of laryngoscopes. Malignant lesions: Early carcinoma of larynx and laryngopharynx Foreign bodies: Larynx and laryngopharynx Strictures: Dilatation of laryngeal strictures. Diagnostic Infants and young children Anatomy: Strong gag reflex or overhanging epiglottis Symptoms: Hoarseness, dyspnea, stridor and dysphagia Examination of hidden areas: Following areas cannot be adequately seen during mirror laryngoscopy: Oropharynx: Base of tongue, valleculae ­ Hypopharynx: Lower part of pyriform fossa ­ Larynx: Infrahyoid epiglottis, anterior commissure, ventricles and subglottic region. Right hand retracts the lips and guides the introduction of laryngoscope and handle suction and forceps. Introduction of scope: Laryngoscope is introduced usually right side of the tongue and is then moved to the midline. Lifting of epiglottis: the lifting of epiglottis forward (without levering laryngoscope on the upper teeth or jaw) provides view of the interior larynx. Interior of larynx: the tip of anterior commissure laryngoscope is advanced further between the vestibular folds (to examine the ventricles and anterior commissure) and the vocal cords (to examine the subglottic region). Telescope: Angled telescopes facilitate examination of the undersurface of vocal cords and subglottic region. Observation: Watch for any spitting of blood, and respiratory distress and cyanosis. Beginning from 5 minutes on 1st day, phonation time is doubled each day until the full conversational speech · Next 2­3 months: Relearn how to sing from the basic level and avoid maladaptive behaviors · After 3 months: Return to professional activity after the permission from your doctor · Observe general laryngeal hygiene and have proper hydration · Take guaifenesin and perioperative antireflux medications · Take professional help from speech language pathologists and vocal pedagogue · Practice easy onset phonation · Avoid vocal abusive behavior · Use appropriate pitch and vocal intensity. Professional voice users should further increase the amount of water if they are traveling by air, are ill, or have demanding or excessive performance schedule · Avoid use of caffeine because of its diuretic nature · Avoid dairy products as they increase the viscosity of secretions and hinder the healthy smooth vibratory function of vocal cords · Avoid tobacco as it contributes to poor laryngeal hygiene · Guaifenesin may thin the secretions. Suction clearance of secretions, blood clots or inspissated mucus plugs: Head injuries, chest trauma, thoracic or abdominal surgery, or coma. Prolonged procedure (> 20 minutes) may cause postoperative subglottic edema in infants and children. Position: Patient is kept in coma position, which prevents aspiration of blood or secretions. Introduction of scope: Bronchoscope is directed perpendicularly until the uvula is passed. It is introduced usually on the right side of the tongue and is then moved to the midline. Rotate the bronchoscope 90° clockwise to bring its beveled tip in the axis of glottis and enter into the trachea. Conventional: Image is viewed at proximal end by the eyepiece or connected to a video display. Larger diameter channels are used for larger laser fibers, electrocautery, cryotherapy probes and expandable balloons. Investigation findings ­ Radiological evidence of extrinsic or intrinsic esophageal disorders ­ Abnormal esophageal manometry ­ Abnormal esophageal pH recording Diseases: Malignancy esophagus, cardiac achalasia, strictures, infectious esophagitis, diverticulum, reflux esophagitis, hiatus hernia, esophageal varices, caustic ingestion, secondary neck node with unknown primary, surveillance for second primary, penetrating trauma to thorax to rule out esophageal injury. Contraindications of rigid esophagoscopy: In most of the following conditions, new generations of flexible gastroscopes can be used successfully. Handle at the proximal end of esophagoscope indicates the direction of the bevel at the distal end. Shoulders are at the edge of operation table and head rests on a special headrest or hold by an assistant. Protection of teeth and lips: Examine the patient for neck stability and loose teeth or dentures. Holding of scope: Esophagoscope is held by its proximal end in right hand and introduced into right side of mouth lateral to the tongue and advanced towards the middle of base of tongue. Laryngopharynx: Esophagoscope is further advanced gently by the left thumb and index finger. This position brings the axes of mouth, pharynx and esophagus in a straight line and Aortic arch and left bronchus: Indentations of aortic arch (aortic pulsation seen and felt) and left bronchus lie about 25 cm from the incisors. Diet: Sips of plain water followed by usual diet may be given in an uneventful esophagoscopy. The patient is usually in left lateral position or in supine and gentle extension of neck with a shoulder roll. The esophagoscope can be deflected in any direction and secretions can be aspirated. Air or water insufflation opens the lumen of esophagus and the endoscope is advanced further. Precision biopsies Removal of small foreign bodies or benign tumors Dilatation of webs or strictures Injection of sclerosing agents in bleeding varices. Flexible bronchoscopy: It offers visions of segmental bronchi and the upper lobe bronchi, which are beyond the reach of rigid bronchoscopes. For the further details regarding the method of use and indications, the reader should refer to the related chapters such as History and Examination and section of Operations. For the related details, see chapters of "Symptoms and Examination" of respective sections. Its bayonet-shaped or bent at an obtuse angle prevents the hand of the surgeon from obstructing the line of vision. Various sizes and shapes of the ear speculums are available, which suit different sizes of the ear canal. The use of the largest ear speculum that can easily enter the canal is safe and provides better view. It is especially useful in examining the ears and nose of infants and bedridden patients. Blunt probe: Use: It is used for palpation of polyp, growths and swellings in the ear canal as well as nasal cavity. Use: It is used for the indirect examination of oropharynx, laryngopharynx and larynx. The size of the nasal speculum should be chosen according to the age of patient and size of the nose. A Thudicum or Vienna type of nasal speculum is held in the left hand, assists in widening the vestibule. The bent end is used for holding the depressor and supports the little finger of the examiner. The other blade depresses the tongue and is used like a lever to depress anterior two-third of the tongue with the fulcrum over the lower teeth. Caution: Touching of the posterior one-third of the tongue usually leads to the gag reflex and not tolerated by the patient. Use: It spreads open the meatus and is used when giving local injection or making an endaural incision. The catch prevents its closure and the blades hold apart the edges of the incision. Uses: ­ Mastoidectomy: They retract soft tissues after incision and elevation of flaps. Use: They are used for the disimpaction and reduction of the fractures of nasal bones. For the detailed procedure and indications, see chapter "Operations of Nose and Paranasal Sinuses". Sphenoid sinus and pituitary fossa surgery: It is also used in the surgeries of sphenoid sinus and pituitary fossa. Blakesley forceps are cutting and are of different sizes and various angles, such as straight and upward curved (30°, 45°, 70° and 90°). Its flat and dull end elevates the flap in an atraumatic way especially in nasal septal surgery. Uses: To give gentle blows on the gouge for removing spur and doing osteotomy in rhinoplasty. Uses: ­ Nasal septum surgery: It is used for removal of septal spurs or bony crests and ridges in nasal septum operation. The tissue caught by the blades may bulge out through the fenestra for a better grip. Uses: ­ Nasal surgery: They are used in nasal surgery to remove polyps, growth and bone/cartilage during Caldwell-Luc operation, septal surgery, and polypectomy (to grasp and avulse polyp). The blade is fitted by swivel joints to the handle so that the blade can rotate through 360° in the joints. Method: It is introduced in a cut of the nasal septal cartilage and is pushed backwards, then downwards and finally forwards to remove a quadrangular piece of the septal cartilage. The blades of this mouth gag fit over the alveolar margins and not over the teeth. The lower jaw is depressed by the surgeon and the closed mouth gag is introduced in between the jaws and is gradually opened. Uses: It retracts the upper lip during Caldwell-Luc operation and maxillectomy operations. Other types of mouth gags are also described in the previous section of this chapter. Uses: It is used for the surgeries of the oral cavity, oropharynx and nasopharynx such as ­ Tonsillectomy ­ Adenoidectomy ­ Snoring surgeries like uvulopalatopharyngoplasty ­ Palatal surgeries ­ Repair of cleft palate ­ Excision of angiofibroma ­ Removal of antrochoanal polyp ­ Craniovertebral anomalies Method: the built in tongue depressor along with the closed mouth gag is inserted in the mouth after depressing the lower jaw. Its C-shaped bent end is used to retract the anterior tonsillar pillar and helps in inspecting the Section 8 figs 17A to D: mouth gags. Uses: It is used for suction in tonsillectomy and other oral, oropharyngeal and nasopharyngeal operations. Method of application: the index and the middle fingers are passed into the two rings on the outer tube of the snare, and the thumb is introduced in the ring of the central movable slide. On closing by pushing the slide into the tube with the thumb, the snare wire loop is withdrawn into the tube of the snare and the tonsil is excised. The shape and size of viewing and distal ends and body vary with the types of laryngoscopes, such as Holinger hourglass, Jako-Cherry, Bouchayer and Dedo. Remaining tags of adenoids may be removed by a smaller plain adenoid curette, Luc forceps or conchotome. Negus Knot tyer: It has a blunt forked end and slips the ligature knot beyond the curved tip of the artery forceps. Method: the sharp trocar tip of closed forceps is inserted into the abscess and then forceps are opened like a sinus forceps to drain the pus. There are openings (vents) at the distal part of the tube for the aeration of the side bronchi. The size of bronchoscope should be selected as per the age of the patient (Table 2). A bronchoscope may be used for performing esophagoscopy but the esophagoscope cannot be used for bronchoscopy. Use: It keeps the cut tracheal edges open so that tracheostomy tube can be easily introduced. Sharp: It retracts the lower border of cricoid cartilage and thus stabilizes the trachea when making incision in the anterior wall of trachea. They can be grouped on the bases of cuff, fenestra, length, number of lumen and the material. Its blunt rounded end is inserted into the outer tube after removing the inner tube. The two blades (bivalve) of the outer tube when pressed together can be easily inserted into the tracheostomy opening.

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