By I. Miguel. Andrew Jackson University. 2018.
Benign prostatic hypertrophy (BPH) is an enlarged Clinical Case Study Answer prostate from unknown causes buy extra super avana 260mg free shipping erectile dysfunction doctor in patna. This condition occurs in nearly one-third of all males over the age of 60 discount extra super avana 260 mg free shipping erectile dysfunction hypertension drugs, and is characterized by The tubular structures that are apparently absent in our patient are the ductus deferentia. This condition, known as congenital bilateral absence of painful and difficult urination. If the urinary bladder is not emp- the ductus deferentia, prevents the transport of spermatozoa from the tied completely, cystitis eventually occurs. This explains the absence of spermatozoa may become incontinent and dribble urine continuously. His ejaculate consists only of the secretions prostatic hypertrophy may be treated by surgical removal of por- from the seminal vesicles (which in many cases are also absent or non- tions of the gland through transurethral curetting (cutting and functional in this deformity) and the prostate. Microsurgical extraction of spermatozoa from the epididymides is now possible, however, and has allowed many afflicted Prostatic carcinoma, cancer of the prostate, is the second men to father children. You examine the patient and consistent with seminoma, the most feel this mass. The remainder of the testis has a Testicular malignancy generally spreads normal texture. You decide that this mass needs to lymphatic drainage generally follows the be further evaluated, so you order a scrotal venous drainage, where would you expect ultrasound. This study shows a 1-cm hy- to find abnormal lymph nodes if this poechoic oval nodule at the upper pole of patient’s disease has spread? Why is ultrasound considered the safest a small hydrocele, a fluid collection in the way to image the scrotum? Male Reproductive © The McGraw−Hill Anatomy, Sixth Edition Development System Companies, 2001 Chapter 20 Male Reproductive System 723 Chapter Summary Introduction to the Male Reproductive 3. The conversion of spermatids to (d) The small bulbourethral glands System (pp. A sperm consists of a head and a flagellum for the erect penis in preparation female reproductive systems is to produce and matures in the epididymides prior to for coitus. The functions of the male reproductive (a) The acrosome of the head contains urinary and reproductive systems, is system are to produce spermatozoa, digestive enzymes for penetrating an divided into prostatic, membranous, and secrete androgens, and transfer ovum. The penis is specialized to become erect include the primary sex organs (the Spermatic Ducts, Accessory for insertion into the vagina during testes), secondary sex organs (those that Reproductive Glands, coitus. The body of the penis consists of three secondary sex characteristics (sexual 1. The epididymides and the ductus columns of erectile tissue, the spongy attractants, expressed after puberty). The saclike scrotum, located in the the tubular structures on the testes where 4. The glans penis is the terminal end, urogenital portion of the perineum, spermatozoa mature and are stored. Each testis is contained within its own ductus deferens forms a component of the and Ejaculation (pp. Erection of the penis occurs as the erectile from the other by the scrotal septum. The seminal vesicles and prostate provide tissue becomes engorged with blood. The testes are partitioned into wedge- (a) The seminal vesicles are located ejaculatory ducts, and ejaculation is the shaped lobules; the lobules are composed posterior to the base of the urinary forceful expulsion of semen from the of seminiferous tubules, which produce bladder; they secrete about 60% of the ejaculatory ducts and urethra of the penis. Spermatogenesis occurs by meiotic just below the urinary bladder; it with blood as arteriole flow increases and division of the cells that line the secretes about 40% of the additive venous drainage decreases. Ejaculation is the result of sympathetic (a) At the end of the first meiotic (c) Spermatozoa constitute less than 1% reflexes in the smooth muscles of the division, two secondary spermatocytes of the volume of an ejaculate.
In and osteoclast activation in response to loading and un- contrast discount extra super avana 260mg online erectile dysfunction world statistics, walking downhill primarily involves muscle ten- loading cheap extra super avana 260 mg with visa erectile dysfunction pills walgreens, physical activity is a major site-specific influence sion development that resists muscle lengthening, or eccen- on bone mineral density and geometry. All routine forms of physical activity, in activity can create excessive strain, leading to inefficiency fact, involve combinations of concentric, eccentric, and iso- in bone remodeling and stress fracture; however, extreme metric contractions. Because less ATP is required for force inactivity allows osteoclast dominance and bone loss. Consequently, However, perhaps because the force per active motor unit is bone strength and density appear to be closely related to greater in eccentric exercise, eccentric contractions can applied gravitational forces and to muscle strength. These include weakness (ap- suggests that exercise programs to prevent or treat osteo- parent the first day), soreness and edema (delayed 1 to 3 porosis should emphasize weight-bearing activities and days in peak magnitude), and elevated plasma levels of in- strength as well as endurance training. Histological ev- calcium is essential for any exercise effect: weight-bearing idence of damage may persist for 2 weeks. Damage is ac- activity enhances spinal bone mineral density in post- 560 PART VIII TEMPERATURE REGULATION AND EXERCISE PHYSIOLOGY Exercise Can Modify the Rate of Gastric Cyclic Emptying and Intestinal Absorption runners Dynamic exercise must be strenuous (demanding more 180 than 70% of the maximal oxygen uptake) to slow gastric emptying of liquids. Little is known of the neural, hor- monal, or intrinsic smooth muscle basis for this effect. Al- though gastric acid secretion is unchanged by acute exer- Controls cise of any intensity, nothing is known about the effects of exercise on other factors relevant to the development or 160 healing of peptic ulcers. There is some evidence that stren- uous postprandial dynamic exercise provokes gastroe- Amenorrheic sophageal reflux by altering esophageal motility. These adaptive responses to chronically increased energy expenditure lead to more rapid processing of food and increased appetite. Animal 140 models of hyperphagia show specific adaptations in the small bowel (increased mucosal surface area, height of mi- FIGURE 30. This graph shows crovilli, content of brush border enzymes and transporters) spine bone density in young adult women who that lead to more rapid digestion and absorption; these are nonathletes (controls), distance runners with regular men- same effects likely take place in humans rendered hyper- strual cycles (cyclic runners), and distance runners with amenor- phagic by regular physical activity. Differences from controls indicate Blood flow to the gut decreases in proportion to exercise the roles that exercise and estrogen play in determination of bone intensity, as sympathetic vasoconstrictor tone rises. Because exercise may also improve gait, balance, malabsorption as a consequence of acute or chronic exercise coordination, proprioception, and reaction time, even in does not occur in healthy people. While exercise may not older and frail persons, the risk of falls and osteoporosis improve symptoms or disease progression in inflammatory are reduced by chronic activity. In fact, the incidence of bowel disease, there is some evidence that repetitive dy- hip fracture is reduced nearly 50% when older adults are namic exercise may reduce the risk for this illness. However, even when Although exercise is often recommended as treatment for activity is optimal, it is apparent that genetic contribu- postsurgical ileus, uncomplicated constipation, or irritable tions to bone mass are greater than exercise. However, of the population variance is genetic, and 25% is due to chronic dynamic exercise does substantially decrease the different levels of activity. In addition, the predominant risk for colon cancer, possibly via increases in food and fiber contribution of estrogen to homeostasis of bone in young intake, with consequent acceleration of colonic transit. These exceptionally active women are typically very thin and exhibit low levels of Chronic Exercise Increases Appetite Slightly circulating estrogens, low trabecular bone mass, and a Less Than Caloric Expenditure in Obese People high fracture risk (Fig. Exercise also plays a role in the treatment of os- Obesity is common in sedentary societies. Controlled clinical trials find that appropriate, creases the risk for hypertension, heart disease, and dia- regular exercise decreases joint pain and degree of disabil- betes and is characterized, at a descriptive level, as an ex- ity, although it fails to influence the requirement for anti- cess of caloric intake over energy expenditure. In rheumatoid arthritis, ex- exercise enhances energy expenditure, increasing physical ercise also increases muscle strength and functional activity is a mainstay of treatment for obesity.
D purchase extra super avana 260 mg amex causes of erectile dysfunction young males, During the afterhyperpolariza- tion buy 260mg extra super avana overnight delivery erectile dysfunction pills cost, the sodium channels are both closed and inactivated, and the K+ potassium channels remain in their Na+ active state. Eventually, the potas- Closed and sium channels close and the sodium D Active state inactive state channel inactivation is removed, so that both channels are in their rest- ing state and the membrane poten- tial returns to resting membrane po- tential. Note that the voltage-gated potassium channel does not have an inactivated state. In this case, the local stimulus is the inward cause the internal axoplasmic resistance, Ra, decreases, al- sodium current that accompanies the action potential. The lowing the current to spread farther down the inside of the larger the space constant, the farther along the membrane axon before leaking back across the membrane. Affected individuals generally have no neurons and muscle cells and in synaptic transmission. The defect in membrane repolar- nel properties derived from biophysical studies of isolated ization could be a result of a prolonged inward sodium cells or their membranes. The advent of molecular ap- current or a reduced outward potassium current. In fact, proaches resulted in the cloning of the genes for a variety mutations in potassium channels account for two differ- of channels and the subsequent expression of these genes ent LQT syndromes, and a third derives from a sodium in a large cell, such as the Xenopus oocyte, for further char- channel mutation. Myotonia is a condition characterized by a delayed re- This approach also allowed experimental manipulation laxation of muscle following contraction. There are several of the channels by expressing genes that were altered in types of myotonias, all related to abnormalities in muscle known ways. Some myotonias are associated with a skele- which parts of channel molecules were responsible for tal muscle sodium channel, and others are associated with particular properties, including voltage sensitivity, ion a skeletal muscle chloride channel. This genetic understand- and spinocerebellar ataxias, some forms of epilepsy, and ing of the control of channel properties led to the realiza- familial hemiplegic migraine. Ataxias are a disruption in tion that many unexplained diseases may be caused by al- gait mediated by abnormalities in the cerebellum and terations in the genes for ion channels. One specific ataxia associated with altered ion channel function are now collectively called an abnormal potassium channel is episodic ataxia with channelopathies. In this disease, which is autosomal-dominant, muscle, cardiac muscle, and even nonexcitable cells, such cerebellar neurons have abnormal excitability and motor as kidney tubular cells. This hyperex- One of the best-known sets of channelopathies is a citability causes indiscriminant firing of motor neurons, group of channel mutations that lead to the Long Q-T observed as the twitching of small groups of muscle fibers, (LQT) syndrome in the heart. The QT interval on the elec- akin to worms crawling under the skin (myokymia). It is trocardiogram is the time between the beginning of ven- likely that many other neuronal (and muscle) disorders of tricular depolarization and the end of ventricular repolar- currently unknown pathology will be identified as chan- ization. This in- axon, more of the adjacent region that is depolarized by crease in Rm increases the space constant. The layers of the inward current accompanying the action potential myelin also decrease the effective capacitance of the axonal reaches the threshold for action potential generation. The membrane because the distance between the extracellular result is that the speed at which action potentials are con- and intracellular conducting fluid compartments is in- ducted, or conduction velocity, increases as a function of creased. Because the capacitance is decreased, the time increasing axon diameter and concomitant increase in the constant is decreased, increasing the conduction velocity. While the effect of myelin on Rm and capacitance are Several factors act to increase significantly the conduc- important for increasing conduction velocity, there is an tion velocity of action potentials in myelinated axons. In myelinated axons, voltage-gated Na CNS wrap themselves around axons to form myelin, layers channels are highly concentrated in the nodes of Ranvier, of lipid membrane that insulate the axon and prevent the where the myelin sheath is absent, and are in low density passage of ions through the axonal membrane (Fig. When an action potential Between the myelinated segments of the axon are the nodes is initiated at the axon hillock, the influx of Na ions of Ranvier, where action potentials are generated.
An in- proinsulin purchase extra super avana 260mg overnight delivery erectile dysfunction doctors knoxville tn, IGF-I can produce some of the effects of in- crease in the blood concentration of GH has direct feed- sulin extra super avana 260 mg visa erectile dysfunction nitric oxide. IGF-I is produced by many cells of the body; how- back effects on its own secretion, independent of the pro- ever, the liver is the main source of IGF-I in the blood. These effects of GH are due to the Most IGF-I in the blood is bound to specific IGF-I-bind- inhibition of GHRH secretion and the stimulation of so- ing proteins; only a small amount circulates in the free matostatin secretion by hypothalamic neurons (see Fig. GH circulating in the blood can enter the intersti- sulin-like activity, so it does not play a physiological role tial spaces of the median eminence of the hypothalamus in the regulation of blood glucose level. GH increases the expression of the genes for IGF-I in various tissues and organs, such as the liver, and stimulates Pulsatile Secretion of GH. Excessive secretion of periodic bursts, which produce large but short-lived peaks GH results in a greater than normal amount of IGF-I in the in GH concentration in the blood. Individuals with GH deficiency have lower than of high GH secretion, somatotrophs release little GH; as a normal levels of IGF-I, but there is still some present, since result, the blood concentration of GH falls to very low lev- the production of IGF-I by cells is regulated by a variety of els. It is believed that these periodic bursts of GH secretion hormones and factors in addition to GH. It acts directly on somatotrophs to inhibit between bursts, when GH secretion is suppressed, are the stimulatory action of GHRH on GH secretion. The net ef- from neural activity generated in higher levels of the CNS, 592 PART IX ENDOCRINE PHYSIOLOGY which affects the secretory activity of GHRH and somato- increase in the blood concentration of the amino acids argi- statin producing neurons in the hypothalamus. Bursts of GH secretion occur during both awake and sleep periods of the day; however, GH secretion is maximal The Actions of GH. The bursts of GH secretion during sleep usually of the body have receptors for GH in their plasma mem- occur within the first hour after the onset of deep sleep branes. The interaction of GH with these receptors pro- (stages 3 and 4 of slow-wave sleep). Mean GH levels in the duces its growth-promoting and other metabolic effects, blood are highest during adolescence (peaking in late pu- but the mechanisms that produce these effects are not fully berty) and decline in adults. The binding of GH to its receptor activates a with aging is mainly due to decrease in the size of the GH tyrosine kinase (JAK2), which initiates changes in the secretory burst but not the number of pulses (Fig 32. These factors are thought to work by changing the the transcription of specific genes, such as that for IGF-I. For example, emotional or physical stress IGF-I; however, evidence indicates that GH has direct causes a great increase in the rate of GH secretion. Vigor- growth-promoting actions on progenitor cells or stem cells, ous exercise also stimulates GH secretion. Obesity results such as prechondrocytes in the growth plates of bone and in reduced GH secretion. GH stimulates such pro- Changes in the circulating levels of metabolites also af- genitor cells to differentiate into cells with the capacity to fect GH secretion. An important action of GH on the tion stimulates GH secretion, whereas hyperglycemia in- differentiation of progenitor cells is stimulation of the ex- hibits it. Growth hormone secretion is also stimulated by an pression of the IGF-I gene; IGF-I is produced and released by these cells. IGF-I exerts an autocrine mitogenic action on the cells that produced it or a paracrine action on neighbor- ing cells. In response to IGF-I, these cells undergo division, 20 causing the tissue to grow mainly through cell replication. As mentioned earlier, GH deficiency in childhood causes 14-year-old boy a decrease in the rate of body growth. Individuals with this condition may be deficient in GH only, or they may have multiple anterior pituitary hormone deficiencies.