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By: L. Gorok, M.B. B.CH. B.A.O., M.B.B.Ch., Ph.D.
Co-Director, University of North Texas Health Science Center Texas College of Osteopathic Medicine
Harmful substances medications cause erectile dysfunction , including nitrogenous wastes and excess electrolytes (sodium medications zofran , potassium treatment notes , and calcium), are excreted from the body as urine, while useful products are returned to the blood. Nitrogenous wastes are toxic to the body, and must be continuously eliminated or death will occur. Electrolyte concentration must remain fairly constant for proper functioning of nerves, heart, and muscles. The kidneys also secrete erythropoietin, a hormone that acts on bone marrow to stimulate production of red blood cells when blood oxygen levels are low. Because they lie outside of the peritoneum, their location is said to be retroperitoneal. In a frontal section, two distinct areas are visible, an outer section, the (2) renal cortex, and a middle area, the (3) renal medulla, which contain portions of the microscopic filtering units of the kidney called nephrons. Near the medial border is the (4) hilum (hilus), an opening through which the (5) renal artery enters and the (6) renal vein exits the kidney. The renal artery carries blood that contains waste products to the nephrons for filtering. After waste products are removed, blood leaves the kidney by way of the renal vein. Waste material, now in the form of urine, passes to a hollow chamber, the (7) renal pelvis. This cavity is an enlarged, funnel-shaped extension of the (8) ureter where the ureter merges with the kidney. Each ureter is a slender tube about 10 to 12 inches long that carries urine in peristaltic waves to the bladder. The (10) urinary bladder, an expandable hollow organ, acts as a temporary reservoir for urine. When empty, the bladder has small folds called rugae that allow expansion as the bladder fills. A triangular area at the base of the bladder called the trigone is delineated by the openings of the ureters and the urethra. The base of the trigone forms the (11) urethra, the tube that discharges urine from the 1 bladder. The length of the urethra is approximately 12 inches in women and about 7 to 8 inches in men. During micturition, urine is expelled through the urethral opening, the (12) urinary meatus. Nephron Microscopic examination of kidney tissue reveals the presence of approximately 1 million nephrons. Anatomy and Physiology 311 urea, uric acid, and creatinine, the end products of protein metabolism. Nephrons also remove excess electrolytes and many other products that exceed the amount tolerated by the body. The renal corpuscle is composed of a tuft of capillaries called the (1) glomerulus and a modified, funnel-shaped end of the renal tubule known as (2) Bowman capsule. A larger (3) afferent arteriole carries blood to the glomerulus, and a smaller (4) efferent arteriole carries blood from the glomerulus. The difference in the size of these vessels provides the needed pressure to force small molecules out of the blood and into Bowman capsule. As the efferent arteriole passes behind the renal corpuscle, it forms the (5) peritubular capillaries. These capillaries allow needed products filtered from the blood in Bowman capsule to re-enter the vascular system. Each renal tubule consists of four sections: the (6) proximal convoluted tubule, followed by the narrow (7) loop of Henle, then the larger (8) distal tubule and, finally, the (9) collecting tubule. The collecting tubule transports newly formed urine to the renal pelvis for excretion by the kidneys. The tubule reclaims needed substances from the filtrate and returns them to the body for reuse.
One method questions deserve special consideration: to medications qid minimize tangential sectioning is to treatment renal cell carcinoma cut these rounded ends like a pie rather than a loaf of 1 medications given during labor . This question often arises in cases tumor nodule, place the at surface of each end of multinodular goiters and encapsulated nodon the cutting board, and then, as illustrated, ules. In multinodular goiters, the thyroid is often direct each cut perpendicular to the tumor massively enlarged, and its cut surface may show capsule as though you were dividing a pie into numerous nodules, hemorrhage, calcication, equal pieces. In these instances, try to avoid the common error of submitting too Regional neck lymph nodes are usually removed many sections. Instead, document the nding separately by the surgeon and submitted as sepawith a photograph and a detailed gross descriprate specimens. Sampling a multinodular goiter should be ented, and each level should be carefully dissected limited to one or two sections selectively taken (see Chapter 10). Each lymph node identied from the periphery of each nodule (up to ve should be submitted for histologic evaluation. Conversely, the more common error when sampling encapsulated nodules is to submit too few sections. Your primary task in Important Issues to Address sampling these lesions is to make sure that areas in Your Surgical Pathology of transcapsular or vascular invasion are not Report on Thyroidectomies missed. Whenever possible, Record the number of lymph nodes with metasthe location of the gland(s) should be spectases and the total number of lymph nodes exied. P arath yroid lan d s 3 Parathyroidectomies specimens, since their size may be critical in distinguishing between an isolated adenoma Parathyroid glands are usually removed from and diffuse hyperplasia. During the removal of these glands, the surgeon often needs With these two questions in mind, the dissechelp identifying parathyroid tissue, determining tion of parathyroid tissue is simple. Measure and whether the parathyroid tissue is proliferative, weigh the specimen, and note its gross appearand distinguishing between hyperplasia involvance including its shape and color. Use a scale ing multiple glands and a neoplasm conned to that is accurate to the nearest milligram. For the surgical pathologist, these portion of the gland has been harvested by the issues translate into two simple questions that surgeon for the purpose of autotransplantation, can be promptly addressed: (1) Is parathyroid ask the surgeon to estimate the weight of the tissue present Because the oval, encapsulated nodules that have a homoparathyroids may lie hidden deep in the parengeneous red-brown cut surface. This gross chyma of these organs, they should be rapidly appearance of the parathyroid is not specic yet thoroughly dissected and inspected. In these and may resemble a lymph node or a thyroid cases, weigh the entire specimen before disnodule. Fortunately, this distinction can be secting it, and then weigh the potential parathymade with speed and relative ease by resorting roid gland alone once any associated tissues have to frozen section evaluation and/or with a been delicately removed. Bisect the parathyroid, touch imprint from the surface of the encapsuand note the appearance of its cut surface. Perhaps the biggest oversight hormone assay is being increasingly used intrawhen evaluating parathyroid tissue is foroperatively to guide the surgical management of getting to weigh the tissue. While histologic primary hyperparathyroidism, in many practices examination is important in conrming the surgeons still request frozen sections to conrm presence of a parathyroid gland, the histologic the removal of parathyroid tissue. Touch imprints ndings may not reliably distinguish between of the cut surface of the specimen (immediately normal and proliferative parathyroid tissue. Therefore, it is critical that from thyroid and lymphoid tissue, and they every specimen potentially representing paraoften serve as a valuable adjunct to the frozen thyroid tissue be accurately weighed. Remember to weigh additional ber to sample other tissues that may be part of 206 37. In the rare logic features, is the tissue most consistent case of a parathyroid carcinoma, sections should with normal parathyroid tissue, multiglanbe submitted in an attempt to document local invadularhyperplasia,oranadenoma
Two of the three studies investigating repeated administration of valerian found that effects were established by 2 weeks treatment goals for depression . The 4-week study involved 121 volunteers and assessed clinical effectiveness using four validated rating scales medicine used to treat bv . At the end of the study medications 2355 , valerian was rated better than placebo on the Clinical Global Impression Scale, and at conclusion of the study (day 28) 66% of patients rated valerian effective, compared to 26% with placebo. Of the six studies investigating acute effects, valerian produced positive results in three whereas in the other three it was no better than placebo. Interpretation of study results is difficult because of varying research methodologies. Additionally, some studies used healthy volunteers with no sleep disturbances with little scope to observe further improvements. Donath et al reported positive effects on sleep structure and sleep perception in subjects with insomnia after taking valerian for 14 days under double-blind crossover conditions, whereas single doses of valerian had no effect on sleep structure or subjective sleep assessment (Donath et al 2000). Participants slept overnight in a sleep laboratory, following a dose of valerian 300 or 600 mg, or placebo at 9 pm and test periods were separated by 6 days of washout. In Queensland, a series of n = 1 tests were carried out to investigate the effectiveness of valerian versus placebo for the management of chronic insomnia in general practice (Coxeter et al 2003). Valerian was not shown to be appreciably better than placebo in promoting sleep or sleep-related factors for any individual patient or for all patients as a group. Tablets were dispensed as per approved dosage recommendations: two tablets at night taken 30 minutes before bed. Comparisons with benzodiazepines Two randomised studies have compared valerian with benzodiazepine drugs. One double-blind trial found that subjects treated with either 600 mg valerian or 10 mg oxazepam experienced significantly improved sleep, with no statistically significant differences detected between the treatments (Dorn 2000). Another study comparing the immediate sedative effects and residual effects of a valerian and hops preparation, a sole valerian preparation, flunitrazepam and placebo found that subjective perceptions of sleep quality were improved in all treatment groups; however, only flunitrazepam treatment impaired performance the morning after as assessed both objectively and subjectively (Gerhard et al 1996). Furthermore, 50% of subjects receiving flunitrazepam reported mild sideeffects compared with only 10% from the other groups. The multicentre trial took place at 24 study centres in Germany and found that valerian treatment was at least as efficacious as oxazepam, with both treatments improving sleep quality. Children the efficacy and tolerability of a valerian and lemon balm combination (Euvegal forte) was tested in a large, open, multicentre study of 918 children (aged under 12 years) with restlessness and nervous sleep disturbance (dyssomnia) (Muller & Klement 2006). The study reported that 81% of children with dyssomnia experienced an improvement and 70% of children with restlessness improved. Each Euvegal forte tablet consisted of 160 mg valerian root dry extract (Valeriana officinalis L. The few studies published thus far have produced encouraging results, but are hampered by methodological problems and well conducted trials are still required. A randomised study found that low-dose valerian (100 mg) reduced situational anxiety without causing sedation (Kohnen & Oswald 1988). Positive results were also obtained in a smaller open study of 24 patients suffering from stress-induced insomnia who found treatment (valerian 600 mg/day for 6 weeks) significantly reduced symptoms of stress and insomnia (Wheatley 2001). Another randomised trial compared the effects of a preparation of valepotriates (mean daily dose 81. Kava kava is a herbal medicine also used in the treatment of anxiety and found to be effective in clinical studies (Pittler & Ernst 2002). A study that compared the effects of kava kava to valerian and placebo in a standardised mental stress test found that both herbal treatments reduced systolic blood pressure, prevented a stress-induced rise in heart rate and decreased self-reported feelings of stress (Cropley et al 2002). Although no controlled studies are available to confirm clinical effectiveness in these conditions, valerian is likely to exert some degree of antispasmodic activity based on its pharmacological actions.