X. Stan. University of Houston.
Mittendorf’s dot purchase top avana 80mg with mastercard impotence ginseng, Bergmeister’s papilla purchase genuine top avana on-line erectile dysfunction fact sheet, and vascular loops (95% of which are arterial) order discount top avana on-line erectile dysfunction caused by lack of sleep. A patient presents with a central retinal artery occlusion and 20/20 visual acuity. Fifteen percent of people have a cilioretinal artery that supplies the macular region. Thirty percent of eyes have a cilioretinal artery supplying some portion of the retina. These are perfused by the choroidal vessels, which are fed by the ophthalmic artery and thus are not affected by central retinal artery circulation. Branch retinal vein occlusions occur at arteriovenous crossings, most commonly where the vein lies posterior to the artery. The superotemporal quadrant is most often affected because of a higher number of arteriovenous crossings on average. Inferonasal extramacular fibers cross in the anterior chiasm and bulge into the contralateral optic nerve (Willebrand’s knee). Temporal macular fibers pass uncrossed through the chiasm, whereas nasal macular fibers cross posteriorly. The visual cortex is situated along the superior and inferior lips of the calcarine fissure. This area is called the striate cortex because of the prominent band of geniculocalcarine fibers, termed the stria of Gennari after its discoverer. What is the most likely anatomic location of pathology associated with downbeat nystagmus? The most common causes are Arnold-Chiari malformation, stroke, multiple sclerosis, and platybasia. As she dumps the plethora of eye drops from her purse, she explains that she has seen seven different doctors and none has been able to help her. The exam shows mild inferior punctate keratopathy but a normal tear lake and normal Schirmer’s test. You are already patting yourself on the back as you ask if the irritation is worse in the morning or evening. You ask her to close her eyes gently and see two millimeters of lagophthalmos in each eye. Basal tear production is provided by the accessory lacrimal glands of Krause and Wolfring. Krause’s glands are located in the superior fornix, and the glands of Wolfring are located above the superior tarsal border. The macula is defined as the area of the posterior retina that contains xanthophyllic pigment and two or more layers of ganglion cells. The fovea is a central depression of the inner retinal surface and is approximately 1. Fluorescein angiography typically shows perfusion of the choroid and any cilioretinal arteries prior to visualization of the dye in the retinal circulation. Fluorescein enters the choroid via the short posterior ciliary arteries, which are branches of the ophthalmic artery. The central retinal artery, also a branch of the ophthalmic artery, provides a more circuitous route for the dye to travel, resulting in dye appearance in the retinal circulation 1–2 seconds later. Explain why visual acuity in infants does not reach adult levels until approximately 6 months of age, based on retinal differentiation. Ganglion cell nuclei are initially found directly over the foveola and gradually are displaced peripherally, leaving this area devoid of accessory neural elements and blood vessels as neural organization develops to adult levels by age 6 months. This delay in macular development is one factor in the inability of newborns to fixate, and improvement in visual activity parallels macular development. The long posterior ciliary nerves branch from the ophthalmic division of the trigeminal nerve and penetrate the cornea. Peripherally, 70–80 branches enter the cornea in conjunctival, episcleral, and scleral planes. The network just posterior to Bowman’s layer sends branches anteriorly into the epithelium. Mucin is secreted principally by the conjunctival goblet cells but also from the lacrimal gland. The aqueous layer contains electrolytes, immunoglobulins, and other solutes, including glucose, buffers, and amino acids. What are the differences in the structure of the central retinal artery and retinal arterioles? The central retinal artery contains a fenestrated internal elastic lamina and an outer layer of smooth muscle cells surrounded by a basement membrane. Macular function is represented in the most posterior portion at the tip of the occipital lobe. However, there may be a wide distribution of some macular fibers along the calcarine fissure. Macular hole formation is a common malady that can result in rapid loss of central vision. Approximately 83% of cases are idiopathic, and 15% are due to some sort of trauma. Gass’s theory proposed that the underlying causative mechanism was centripetal tangential traction by the cortical vitreous on the fovea. He also proposed the following stages: & Stage 1a: Tractional elevation of the foveola with a visible yellow dot & Stage 1b: Enlargement of the tractional detachment with foveal elevation. Occasionally patients may develop an intraretinal split with formation of a foveal cyst. This cyst may evolve into a full-thickness hole with disruption of the inner retinal layer and opening of the foveal floor. These findings suggest a complex array of both anterior-posterior and tangential vector forces as an etiology for molecular hole formation. Clearly the classification of macular holes will need to be reworked in light of these new findings. Frontal bone Trochlea The circle defined by the superior rectus muscle, Ethmoid bone Sphenoid Anterior inferior rectus muscle, lacrimal bone crest lateral rectus muscle, and Interior orbital Posterior medial rectus muscle (see lacrimal crest tissues Fig. What nerves pass foramen through the superior Intraorbital glove Zygomaticomaxillary suture orbital fissure but Maxillary bone outside the annulus of Zinn? What are the surgical landmarks in locating the superficial temporal artery during temporal artery biopsies? The superficial temporal artery lies deep to the skin and subcutaneous tissue but superficial to the temporalis fascia. The lower lid retractors consist Capsulopalpebral Pretarsal fascia orbicularis of the capsulopalpebral fascia muscle and the inferior tarsus muscle. The capsulopalpebral Lower lid retractors fascia of the lower lid is Preseptal analogous to the levator complex orbicularis in the upper lid.
Cystoscopy may show sandy patches of It is associated with chronic cystitis of removed generic top avana 80mg with visa erectile dysfunction new zealand. The surround- and the bladder shrink’s until it may have a Treatment ing mucosa is edematous order cheap top avana on line erectile dysfunction protocol scam or not, hyperemic and small capacity quality 80 mg top avana impotence urban dictionary. Bladder sis consists of a single dose of praziquantel, Histologically, the plaques are made augmentation may be done either by ile- which for safety may be repeated afer a up of large foamy macrophages with occa- ocystoplasty or cecocystoplasty. In addition mineralized the bladder is augmented with a segment of formed by light diathermy coagulation. Secondary neoplasms Grading contraction and clinically manifested by fre- • From the kidneys-papilloma and Tere are three Grades G1, G2 and G3. G2 = moderately diferentiated The common causes are: • From the prostate cancers and G3 = poorly diferentiated 1. T = Primary tumor • Cystoscopy Bladder cancer is more common in males Ta = Noninvasive papillary carcinoma • Cystography and usually occurs afer the age of 50. Augmentation of bladder capacity by rubber industry are more susceptible to half). Smoking increases the risk of developing T4a = Tumor invades prostate or uterus Classifications bladder carcinoma. Pelvic irradiation T4b = Tumor invades pelvic wall or abdom- percent of the bladder tumors originating 5. Chronic cystitis – Tis may lead to squa- N = Metastasis in a single lymph node 1 – Adenoma mous cell metaplasia leading and squa- 2cm or less in greatest dimension. Squamous cell carcinoma following Like cancer anywhere bladder cancer may than 5cm in greatest dimension. Connective tissue (Mesenchymal) tumors appear entirely normal or as fat plaques M = No distant metastasis. Clinical features • Partial cystectomy (partial bladder resec- • Painless hematuria (95%) is the most tion) can be done for localized lesions sit- Prognosis common symptom, dysuria or frequency uated away from ureteral orifces and the i. Fixed tumors and metastasis-Median • Abdominal examination is negative unless fxed tumors (T4a and T4b). Surgery Urinary incontinence is defned as the invol- Investigations untary loss of urine. The three cardinal investigations in nence is loss of urine through a channel other patients with hematuria are urine analysis, Once the tumor has invaded the superfcial than the urethra, e. Cystoscopy shows the growth and per- terosigmoidostomy) or orthotopic bladder volume without a rise in pressure. In this operation, the bladder with the tors in the bladder wall will initiate a refex stage the invasive tumors. Surgery-Transurethral resection of excellent chance of tumor cure and preserva- turition. Principles of Management usually older and frailer and possibly have If the integration pathway from the pons The most important aspect in the manage- more advanced disease than a comparable is interrupted, the function of sacral spi- ment of bladder tumors is to evaluate the cystectomy group. Stress incontinence or incontinence due to The urine losses usually range from 10 to females with stress incontinence. Overfow incontinence – Tere is invol- It can diferentiate between urge and obstruction, e. Stress incontinence usually occurs afer without cystogram if vesicovaginal fstula repeated childbirths. Continual or extraurethral incontinence, It is of two types: Acute retention and chronic e. Pelvic foor exercises and weight • Acute retention is the sudden inability Tis type of incontinence also occurs in reduction if the patient is obese. Overfow incontinence is an uncon- • In stress incontinence, there is loss of Local or systemic estrogen reduces trollable leakage and dribbling of urine urine during coughing, sneezing, strain- urine leakage by proliferation of ure- from the urethra in a case of chronic ing, weight lifing, etc. Conservative measures: Before a catheter the fstula is better seen with a contrast enema. If all the above measures fail, the bladder It is the diversion of urine temporarily or per- b. Diabetes-progressive lower motor between one hollow viscus and another or stage incontinence that is not other- neuron pattern (faccid bladder). Drugs like narcotics, anticholiner- lowing neglected obstructed child- birth bladder cancer. Nephrostomy (open and percutaneous • Blood urea and electrolytes estimation to disease and postirradiation necrosis. Intestinal conduit using either ileum or • Plain abdominal X-ray to see bladder cal- Tere is escape of urine in both vesicovaginal colon. In vesicoenteric fstula, the most striking Suprapubic Cystostomy • Urodynamics-allows identifcation and feature is the passage of turbid urine, containing It is commonly indicated for: assessment of neurologic bladder dys- recognizable fecal contents and fecal organisms. The catheter is connected to a closed drainage system and is changed every 4 weeks due to occurrence of encrus- tation and obstruction by phosphate debris. The technique involves division of the ureters which are pulled into the sigmoid fig. As a result this Here the ureters are mobilized and a loop the pons, the pontine micturition center center becomes excited and the desire to of ileum with intact vascularity is isolated. The middle portion is formed into a urethrae (external urethral sphincter) is reservoir. Tus, the bladder is analogous to the skel- • Anticholinergic drugs like oxybutynin, etal muscle in that neural control can be propantheline bromide, etc. A neurogenic or cord bladder is one in which The features of neurogenic bladder Bladder (fig. Tumors • Voluntary micturition is under the con- This is due to lesions above the sacral mic- 3. Following this phase the blad- der may become either spastic or remains faccid depending on the level of spinal cord injury as mentioned above. During the stage of spinal shock, the blad- der has to be drained preferably by intermit- tent catheterization. If there is severe spinal cord injury, there is Complications Tere is accumulation of huge residual a stage of faccid paralysis, below the level • Recurrent urinary tract infections. Hypotension due to cardiogenic shock hemoglobinemia and antibodies (Myocardial infarction, constrictive peri- against red cells. Renal causes: (intrinsic renal failure) multiple factors are involved ing over a period of hours to days resulting i. Loss of fuid and salt drome in which there is severe arterial thrombosis, emboli or stenosis, a. From the gut in severe vomiting, contusion of the muscles of the bilateral renal vein thrombosis. Section 12 Urology by stones and tumor, or bladder outfow pyelography may help in assessing the vi. Antibiotics may be needed to avert infec- obstruction due to prostatic hypertrophy nature and site of the obstruction.
The nodules ulcerate and hematog- to move their limbs beneft from passive which may be enlarged buy cheap top avana 80mg online erectile dysfunction when young. Amputation is recom- A benzopyrone compound order top avana canada erectile dysfunction treatment in rawalpindi, coumarin Treatment mended because of the aggressive nature of (Lympedein) is found to be very efective in • Strict bed rest with elevation of the the tumor generic 80 mg top avana with amex impotence causes cures. Neoplasms of Lymphatics react to minor stimuli with lymphoid hyper- If eczema is present this is treated by tri- plasia. Lymphangioma results in most cases (80%) from benign Lymphangiomas are analogous to hemangi- causes whereas in persons more than 50 Surgery omas of blood vessels. Functional impairment of the limb for its Tree types are usually seen: The various causes of lymphadenopathy weight and bulk. Chronic: Tis is also called reduction plasty of Homan head and neck region as well as in the axilla. Nonspecifc chronic pyogenic lympha- and involves raising skin faps to allow the Histologically they are composed of a net- denitis excision of a wedge of skin and a large volume work of endothelium lined lymph spaces. Involves total excision of skin and subcuta- – Malignant histiocytosis neous tissue followed by skin grafing (split Cystic Hygroma – Chronic lymphatic leukemia. Metastatic: It can occur from many types applied over the foot and leg to prevent undue oma comprising large cyst-like cavities con- of carcinomas, e. Modifcation of the therapy Lymph node tuberculosis is the common- is required for reasons such as intolerance est form of extrapulmonary tuberculosis. It Clinical Examination to a drug, resistance to frst line drugs, commonly afects children and young adults Local examination reveals enlarged mat- etc. Cold abscesses are aspirated from a in order of frequency are the cervical lymph formation. The nodes are initially discrete but Differential Diagnosis soon get matted because of periadenitis. All causes of lymphadenopathy but one Lymphomas-Malignant Tumors should specially exclude lymphomas and of the Lymphoid Tissues Pathology malignancy. The disease runs through the following Investigations: Hodgkin’s Lymphoma stages: (Fig. Tere is periad- Cytologically epithelioid cells and Pathology enitis and caseation. Treatment of tuberculous lymphadenitis is neal region, hepatosplenomegaly are more is common among the children and young primarily by antimycobacterial drug ther- suggestive of non Hodgkin’s lymphoma. The primary treatment is started with Microscopic Examination Tese is destruction of the nodal architecture and replacement by a mixture of lymphocytes and plasma cells with large, pale stain- ing histiocyte-like cells. Some of these are multinucleate or binucleate with prominent nucleoli and a ‘mirror image’ confguration. Reye’s classifcation: Depending on the type of cells, four distinc- tive patterns have been defned viz. To rule out secondaries in the liver defciency states and in postorgan trans- phocyte depletion type is the most ominous b. Lymph node biopsy-Incision biopsy is Classification done and a neck node is usually removed. B symptoms are treated by chemotherapy of neoplastic cells outside the capsule of Tis is followed by axillary and inguinal because it is considered a systemic disease. Various sufxes are added to each ana- Clinical Features tomical stage: Etiology • Compared to Hodgkin’s lymphoma, which A-No systemic symptoms • No single causative abnormality described. Most patients will respond to • Radiotherapy: It is indicated for a few • Compression syndromes may occur-gut oral therapy with chlorambucil, which is patients with stage I disease, for spinal obstruction, ascites, superior vena caval well-tolerated. Nodal spread Discontinuous Contiguous Asymptomatic patients may not require ther- 3. Bone marrow involvement Common Uncommon ing discomfort or disfgurement, bone – mar- 6. Chromosomal translocation Common Yet to be described row failure or compression syndromes. On the lef side it is related to the termi- In the neck, it commences in the median In the thorax, anteriorly from above nal part of the aortic arch, the lef recurrent plane and deviates slightly to the lef as it downwards it is crossed by the trachea, the lef laryngeal nerve,lef subclavian artery and the approaches the thoracic inlet. Below the root of the lung the vagi form a plexus on the surface of the oesopha- gus, the lef vagus lying anteriorly, the right posteriorly. In the abdomen,esophagus passes through the opening in the right crus of diaphragm and comes to lie on the esophageal groove on the posterior surface of the lef lobe of the liver, covered by peritoneum on its anterior and lef aspects. Histology It contains no serosal covering unlike the rest of the gastrointestinal tract. Blood supply: Blood supply is from the infe- rior thyroid artery, branches of the descend- ing thoracic aorta and the lef gastric artery. The veins from the cervical part drain into the inferior thyroid veins and from the tho- racic and abdominal portions, into the azygos Fig. Section 8 Gastrointestinal Surgery Lymphatics • Benign stricture secondary to Special Investigations The lymphatic drainage is from a peri– refux esophagitis and caustic Tese are done to confrm the diagnosis. Barium swallow-It may show narrowing mediastinal nodes which drain both into the • Carcinoma esophagus. Motility disorders like achalasia, and associated with irregular margin (rat the lef gastric vessels. General causes Tis condition can be defned as the neuromus- and at diaphragmatic opening (T10). Hence, the other name is mega-osohphagus in these situations and endoscopes should be d. Globus hystericus (functional)-It is a nal and circular muscle fbers is present but Sphincters of Esophagus neurotic symptom in patient with emo- defective. Peristalsis in the central portion of Clinical Features esophagus consists of wave-like movements Investigation of Dysphagia 1. Age-The condition commonly occurs in that pass down the body of oesophagus and young adults and in the middle aged. Esophageal peristaltic pressures range from Tere may be a history of swallowed caustic 2. The main symptoms are dysphagia, regur- The lower esophageal sphincter is a high A previous history of refux esophagitis gitation and chest pain. The dysphagia is more marked with liq- portion of the esophagus and functions to In esophageal motility disorders, dys- uids and less to solids as the weight of the prevent gastroesophageal refux. The causes of dysphagia may be listed as • In Plummer–Vinson syndrome, there will Investigations follows: be presence of a smooth tongue, anemia 1. In the wall: • Enlarged cervical lymph glands may be unrelaxing narrowed segment at the lower a. Predisposing The treatment of choice is surgery (Heller’s factors are: Clinical Features operation). Barrett’s esophagus due to untreated or duces dysphagia and obstruction to solid the muscle of the lower end of the esophagus silent gastroesophageal refux. Secondary involvement from gastric car- • Extreme weight loss, anorexia, fatigue in a similar manner to Ramstedt’s operation cinoma at cardiac end. Esophageal disorders like achalasia, esopha- usually result in malignant cachexia. In some centers, disruption of the con- gitis (long–standing), Plummer–Vinson • Hoarseness is due to lef recurrent laryngeal stricting fbers is performed with forcible syndrome.
They are mediated by multiple chemical messengers acting at many different G protein–coupled metabotropic receptors top avana 80mg on-line erectile dysfunction can cause pregnancy. Metabotropic receptors characteristically activate a specific intracellular effector (e purchase top avana 80 mg on-line erectile dysfunction doctor in bhopal. Many neurotransmitter-binding metabotropic receptors activate second messenger pathways by activating intracellular cascades cheap top avana 80mg on line impotence medication. Histamine, for example, is released from mast cells during hypersensitivity reactions (e. Muscle contractile responses and glandular secretory responses are slow events and take place over several seconds. Experimental stimulation of secretion is seen as an increase in ion movement (short-circuit current). Slow inhibitory postsynaptic potentials in inhibitory motor neurons result in prolonged inhibition of contractile activity in the muscle, which is observed as decreased contractile tension. Multiple kinds of receptors mediate enteric slow inhibitory postsynaptic potentials. This action is limited to subpopulations of neurons and is blocked by the antagonist naloxone. Addiction to morphine may be seen in enteric neurons, and withdrawal is observed as a high-frequency spike discharge on the addition of naloxone during chronic morphine exposure. Presynaptic inhibition functions like a specialized form of neurocrine transmission. Presynaptic inhibition resulting from paracrine or endocrine mediators binding receptors at presynaptic release sites is an alternative to axoaxonal synapses as a mechanism for enhancing or suppressing transmission at a synapse or neuroeffector junction. Presynaptic3 inhibition mediated by paracrine or endocrine release of mediators is significant in pathophysiologic states (e. Transmitters released from excitatory musculomotor axons can trigger muscle contraction by depolarizing the muscle fiber membrane to the threshold for the discharge of action potentials. In the second 2+ mechanism, the activation of G protein–coupled receptors is linked to the direct release of Ca from stores inside the muscle fiber (i. The cell bodies of excitatory musculomotor neurons are generally found in the myenteric plexus. In the small and large intestine, they project their axons over relatively short distances to innervate the longitudinal muscle and for longer distances away from the cell body in the oral direction to innervate the circular muscle. Excitatory motor neurons, also called secretomotor neurons, innervate mucosal secretory glands (i. Hyperactivity of these neurons, like that evoked by histamine release from enteric mast cells during allergic responses, can lead to neurogenic secretory diarrhea. The longitudinal muscle layer of the small intestine appears not to have a significant inhibitory musculomotor innervation, but there is significant inhibitory musculomotor innervation of the taeniae coli of the large intestine in humans. An absolute requirement for inhibitory neural control of the circular muscle layer is a demand that emerges from the specialized physiology of the musculature (see earlier discussion on electrical syncytial properties). Why does the circular muscle not always respond with action potentials and contract during every slow-wave cycle? Why do action potentials and contractions not spread in the syncytium throughout the entire length and circumference of the intestine each time they occur? The short answer is that inhibitory neuronal motor activity determines when a slow wave can evoke a contraction and determines the distance and direction over which a contraction spreads within the muscular syncytium. This kind of continuous discharge of action potentials by subsets of intestinal inhibitory musculomotor neurons occurs in all mammals. When the inhibitory neural discharge is blocked with tetrodotoxin, every cycle of the electrical slow wave triggers discharge of action potentials and large-amplitude contractions. Tetrodotoxin selectively blocks neural activity without affecting the muscle, which makes it a valuable tool for demonstrating ongoing inhibition of contractile activity. The rising phase of circular muscle action potentials reflects opening of 2+ Ca channels and inward current that is unaffected by tetrodotoxin (see Chapters 3 and 8). As a general rule, any treatment or condition that removes or inactivates inhibitory musculomotor neurons results in tonic contracture and continuous, uncoordinated contraction of the circular musculature. Force of gut smooth muscle contraction is directly related to the activation of the inhibitory neurons. The force of a circular muscle contraction evoked by a slow-wave cycle is a function of the number of inhibitory musculomotor neurons in an active state. This means that inhibitory musculomotor neurons determine when the continuously running slow waves initiate a contraction as well as the force of the contraction, which is determined by the number of muscle fibers responding. With maximum inhibition, no contractions are permitted during a slow-wave cycle (see Fig. Intermediate strength contractions are graded in force according to the number of inhibitory musculomotor neurons that are inactivated during each slow-wave cycle. Motor behavior of the antral pump consists of leading and trailing contractile components triggered by gastric action potentials. Once initiated, the action potentials propagate rapidly and spread through the gastric electrical syncytium, traveling around the gastric circumference and triggering a ringlike contraction, which then travels more slowly toward the gastroduodenal junction. The pacemaker region generates action potentials and associated antral contractions at a frequency of 3 contractions/min. The gastric action potential lasts about 5 seconds and has a rising phase (depolarization), a plateau phase, and a falling phase (repolarization) (see Fig. The propulsive contractile behavior in the antral pump has two components; an antral leading contraction, of relatively constant amplitude, is associated with the rising phase of the action potential, and an antral trailing contraction, of variable amplitude, is associated with the plateau phase (see Fig. Nevertheless, trailing contractions only appear when the plateau phase is at or above threshold, and they increase in strength in direct relation to increases in the amplitude of the plateau potential above threshold. Gastric action potentials are characterized by an initial rapidly rising upstroke followed by a plateau phase and then a falling phase back to the baseline membrane potential (see Fig. The rising phase of the gastric action potential accounts for a leading contraction that propagates toward the pylorus during one propulsive cycle. The strength of the leading contraction is relatively constant; the strength of the trailing contraction is variable and increases in direct relation to neurally evoked increases in amplitude of the plateau phase of the action potential. The leading contractions produced by the rising phase of the gastric action potential have negligible amplitude as they propagate to the pylorus. As the rising phase reaches the terminal antrum and spreads into the pylorus, contraction of the pyloric muscle closes the orifice between the stomach and duodenum. As the trailing contraction, which follows the leading contraction by only a few seconds, approaches the closed pylorus, the gastric contents are forced into an antral compartment of ever-decreasing volume and progressively increasing pressure. This results in jetlike retropulsion through the orifice formed by the trailing contraction (Fig. Trituration and reduction in particle size occur as the material is forcibly retropulsed through the advancing orifice and back into the gastric reservoir to wait for the next propulsive cycle. Repetition, at 3 cycles/min, reduces particle size to the 1- to 7-mm range that is necessary before a particle can be emptied into the duodenum during the digestive phase of gastric motility. The force for retropulsion is increased pressure in the terminal antrum as the trailing antral contraction approaches the closed pylorus. The magnitude of the effects is directly related to the concentration of neurotransmitter present in the neuromuscular junction; an increase in the frequency of action potentials causes a corresponding increase in the amount of neurotransmitter. In this way, the firing of musculomotor neurons determines whether or not a trailing antral contraction occurs.