By N. Ortega. Gwynedd-Mercy College. 2019.
Fugh- Berman and Cott concluded that “side effects from the use of ginkgo are rare order 120 mg sildalis otc. Side effects include nausea generic sildalis 120 mg mastercard, headache buy discount sildalis 120mg, stomach problems, diarrhea, allergy, anxiety, and 32 restlessness. However, most reports of seizures have been due to eating ginkgo seeds, rather than the leaf extract, which is the standardized study product. Still, according to the Natural Standard, overall, ginkgo leaf extract appears to be well tolerated at recommended doses for up to six months. For instance, in 2008, tests on seven of the most popular ginkgo products sold in the United States found that five were contaminated or low in key compounds. Inositol has been shown in very small studies to be helpful for depression and panic disorder, and promising for treatment of obsessive-compulsive disorder, eating disorders and bipolar disorder. Research has not yet shown any adjunctive benefit when inositol is used with psychotropic drugs. Writing in Mischoulon and Rosenbaum’s compendium, Belmaker and Levine propose inositol as a stand-alone supplement for depression and panic disorder rather than as a complement for other psychotropic drugs, noting responses in the same people and no proven additional benefit from using both drugs in combination. Other Mental Health Conditions Though promising, due to study design issues inositol has not yet been established as a treatment for obsessive-compulsive disorder, bipolar disorder, and eating disorders. Gastrointestinal side effects may be a problem for some people, but inositol is generally well tolerated and appears to have a favorable safety profile. However, there have been case reports of inositol-induced mania in people with bipolar disorder. It is uncertain how significant this effect would be if inositol were in wider use as a supplement. People with bipolar disorder should exercise appropriate caution, including consideration of using a mood stabilizer while using inositol. It is promising for bipolar disorder, anxiety, obsession, compulsion, eating disorders, hostility, sadness, tension and fatigue. It is often sold as a dietary supplement in combination with other nutraceuticals. Inositol is present in a variety of foods, particularly beans, grains, nuts, and many fruits. Inositol is classified as a member of the vitamin B family, specifically vitamin B8. The depression study is the most robust, but the panic disorder results are also significant. The significance of this result is limited by the size of the study (27 subjects) and the four- 7 week duration. Attacks fell from ten to six on placebo and from ten to three and a half on inositol. Inositol outperformed placebo in three of the five controlled studies, but all sample sizes were small, and statistical significance was reached in only one study. The obsessive-compulsive study used a crossover design that makes it hard to evaluate, since there is a delay in the effects of inositol supplementation. The obsessive-compulsive disorder and eating disorder studies all used a crossover design that makes them hard to evaluate, since there is a delay in the effects of inositol supplementation. Eleven volunteers were given inositol or placebo in a double-blind, randomized, crossover design. Inositol was found to reduce depression, hostility, tension and fatigue compared with placebo over six hours. Side effects reported in the reviewed clinical trials, at doses of inositol ranging from 6 to 25 g per day, include mild increases in plasma glucose, flatus, nausea, sleepiness, insomnia, dizziness and headache. However, there have been case reports of inositol-induced mania in bipolar depressed patients. People with bipolar disorder should exercise appropriate caution, including consideration of a mood stabilizer while using inositol. There are no studies or cautions concerning use of inositol in breast-feeding women or in children, but Lake and Spiegel caution that inositol may cause uterine contractions, ruling out its use in pregnant women. Kava is generally safe for short-term use but can in rare cases cause catastrophic damage to the liver. Thus, its use is very controversial, and the sources are split four to three on whether it should ever be recommended. Alcohol, other sedatives, muscle relaxants, dopamine, haloperidol, acetaminophen, and benzodiazepines. Taking kava with alcohol, other sedatives, or muscle relaxants can result in additive effects up to and including coma. Alcohol or acetaminophen (Tylenol), which may injure the liver, should never be used with kava. Kava may interfere with the effects of dopamine and drugs that are similar to dopamine and may worsen the neurological side effects of drugs that block dopamine, such as haloperidol (Haldol). Kava may also cause anesthesia to last longer and use should be carefully coordinated with the prescribing physician or anesthesiologist. Lake and Spiegel, Mischoulon and Rosenbaum, the Natural Standard, and Weil counsel that kava should be avoided in individuals with a history of liver disease or alcohol use, and in those who are taking concurrent medications with potential liver toxicity. Mischoulon and Rosenbaum conclude: “Kava should be prescribed and used with great caution. More research pinpointing risk factors could modify these recommendations, since liver toxicity appears to be extremely rare, and bad experience with other anxiolytics could prompt a trial of kava if the risk factors appear to be low, with proper medical supervision. Pregnancy, lactation or child use would appear not to impose a separate challenge. The risk of liver damage is substantial and may be irreversible, even though it appears to be rare. Kava, Piper methysticum, is native to the islands of the South Pacific and is a member of the pepper family. The root and rhizome (underground stem) of kava are used to prepare beverages, extracts, capsules, tablets, and topical solutions. Kava has been used to help people fall asleep and fight fatigue, as well as to treat asthma and urinary tract infections. Six sources confirm the beneficial uses of kava as a mild intoxicant and analgesic, but Brown et al.
Rather than simply trying to remember the schools and their characteristics order 120mg sildalis with mastercard, you might try to relate the information to things you already know purchase sildalis 120mg with mastercard. For instance effective sildalis 120mg, you might try to remember the fundamentals of the cognitive school of psychology by linking the characteristics to the computer model. For instance, you might link the cognitive school to structuralism because both were concerned with mental processes. That image might help you remember that childhood experiences were an important part of Freudian theory. Each person has his or her unique way of elaborating on information; the important thing is to try to develop unique and meaningful associations among the materials. Research Focus: Elaboration and Memory  In an important study showing the effectiveness of elaborative encoding, Rogers, Kuiper, and Kirker (1977) studied how people recalled information that they had learned under different processing conditions. All the participants were presented with the same list of 40 adjectives to learn, but through the use of random assignment, the participants were given one of four different sets of instructions about how to process the adjectives. Participants assigned to the structural task condition were asked to judge whether the word was printed in uppercase or lowercase letters. Participants in the phonemic task condition were asked whether or not the word rhymed with another given word. In the semantic task condition, the participants were asked if the word was a synonym of another word. And in the self-reference task condition, participants were asked to indicate whether or not the given adjective was or was not true of themselves. After completing the specified task, each participant was asked to recall as many adjectives as he or she could remember. Rogers and his colleagues hypothesized that different types of processing would have different effects on memory. This finding, known as the self-reference effect, is powerful evidence that the self-concept helps us organize and remember information. The next time you are studying for an exam, you might try relating the material to your own experiences. The self-reference effect suggests  that doing so will help you better remember the information (Symons & Johnson, 1997). Using the Contributions of Hermann Ebbinghaus to Improve Your Memory Hermann Ebbinghaus (1850–1909) was a pioneer of the study of memory. In this section we consider three of his most important findings, each of which can help you improve your memory. Ebbinghaus plotted how many of the syllables he could remember against the time that had elapsed since he had studied them. He discovered an important principle of memory: Memory decays rapidly at first, but the amount of decay levels off with time (Figure 8. Although Ebbinghaus looked at forgetting after days had  elapsed, the same effect occurs on longer and shorter time scales. Bahrick (1984) found that students who took a Spanish language course forgot about one half of the vocabulary that they had learned within three years, but that after that time their memory remained pretty much constant. Ebbinghaus also discovered another important principle of learning, known as the spacing effect. The spacing effect refers to the fact that learning is better when the same amount of study is spread out over periods of time than it is when it occurs closer together or at the same time. This means that even if you have only a limited amount of time to study, you‘ll learn more if you study continually throughout the semester (a little bit every day is best) than if you wait to cram at the last minute before your exam (Figure 8. Another good strategy is to study and then wait as long as you can before you forget the material. Then review the information and again wait as long as you can before you forget it. The spacing effect is usually considered in terms of the difference between distributed practice (practice that is spread out over time) and massed practice (practice that comes in one block), with the former approach producing better memory. Leslie, Lee Ann, and Nora all studied for four hours total, but the students who spread out their learning into smaller study sessions did better on the exam. Ebbinghaus also considered the role of overlearning—that is, continuing to practice and study even when we think that we have mastered the material. Ebbinghaus and other researchers have  found that overlearning helps encoding (Driskell, Willis, & Copper, 1992). Students frequently think that they have already mastered the material but then discover when they get to the exam that they have not. The point is clear: Try to keep studying and reviewing, even if you think you already know all the material. Retrieval Even when information has been adequately encoded and stored, it does not do us any good if we cannot retrieve it. Retrieval refers to the process of reactivating information that has been stored Attributed to Charles Stangor Saylor. You can get an idea of the difficulty posed by retrieval by simply reading each of the words (but not the categories) in the sidebar below to someone. Tell the person that after you have read all the words, you will ask her to recall the words. After you read the list to your friend, give her enough time to write down all the words that she can recall. Make sure that she cannot recall any more and then, for the words that were not listed, prompt your friend with some of the category names: “Do you remember any words that were furniture? Retrieval Demonstration Try this test of the ability to retrieve information with a classmate. Apple (Fruit) Dresser (Furniture) Sander (Tool) Pomegranate (Fruit) Sunflower (Flower) Tangerine (Fruit) Chair (Furniture) Peony (Flower) Banana (Fruit) Sofa (Furniture) Bench (Furniture) Strawberry (Fruit) Television stand (Furniture) Magnolia (Flower) Attributed to Charles Stangor Saylor. Read your friend the names of the 10 states listed in the sidebar below, and ask him to name the capital city of each state. Now, for the capital cities that your friend can‘t name, give him just the first letter of the capital city. You‘ll probably find that having the first letters of the cities helps with retrieval. The tip-of-the-tongue experience is a very good example of the inability to retrieve information that is actually stored in memory. States and Capital Cities Try this demonstration of the tip-of-the-tongue phenomenon with a classmate. Georgia (Atlanta) Maryland (Annapolis) California (Sacramento) Louisiana (Baton Rouge) Florida (Tallahassee) Colorado (Denver) New Jersey (Trenton) Arizona (Phoenix) Nebraska (Lincoln) Attributed to Charles Stangor Saylor.
Although most weight loss can be maintained for about a year cheap 120 mg sildalis, very few people are able to maintain substantial weight loss through dieting alone  for more than three years (Miller generic sildalis 120mg online, 1999) sildalis 120mg with amex. Substantial weight loss of more than 50 pounds is typically seen only when weight loss surgery has been performed (Douketis, Macie, Thabane, &  Williamson, 2005). Weight loss surgery reduces stomach volume or bowel length, leading to earlier satiation and reduced ability to absorb nutrients from food. Although dieting alone does not produce a great deal of weight loss over time, its effects are substantially improved when it is accompanied by more physical activity. People who exercise regularly, and particularly those who combine exercise with dieting, are less likely to be obese  (Borer, 2008). Exercise increases cardiovascular capacity, lowers blood pressure, and helps improve diabetes,  joint flexibility, and muscle strength (American Heart Association, 1998). Exercise also slows the cognitive impairments that are associated with aging (Kramer, Erickson, & Colcombe,  2006). Because the costs of exercise are immediate but the benefits are long-term, it may be difficult for people who do not exercise to get started. It is important to make a regular schedule, to work exercise into one‘s daily activities, and to view exercise not as a cost but as an opportunity to Attributed to Charles Stangor Saylor. Exercising is more fun when it is done in groups,  so team exercise is recommended (Kirchhoff, Elliott, Schlichting, & Chin, 2008). A recent report found that only about one-half of Americans perform the 30 minutes of exercise 5 times a week that the Centers for Disease Control and Prevention suggests as the minimum  healthy amount (Centers for Disease Control and Prevention, 2007). As for the other half of Americans, they most likely are listening to the guidelines, but they are unable to stick to the regimen. Almost half of the people who start an exercise regimen give it up by the 6-month mark  (American Heart Association, 1998). This is a problem, given that exercise has long-term benefits only if it is continued. Sex: The Most Important Human Behavior Perhaps the most important aspect of human experience is the process of reproduction. Successful reproduction in humans involves the coordination of a wide variety of behaviors, including courtship, sex, household arrangements, parenting, and child care. The Experience of Sex The sexual drive, with its reward of intense pleasure in orgasm, is highly motivating. The  biology of the sexual response was studied in detail by Masters and Johnson (1966), who monitored or filmed more than 700 men and women while they masturbated or had intercourse. Masters and Johnson found that the sexual response cycle—the biological sexual response in humans—was very similar in men and women, and consisted of four stages: Excitement. Women‘s breasts and nipples may enlarge and the vagina expands and secretes lubricant. Muscular contractions occur throughout the body, but particularly in the genitals. The spasmodic ejaculations of sperm are similar to the spasmodic contractions of vaginal walls, and the experience of orgasm is similar for men and women. The woman‘s orgasm helps position the  uterus to draw sperm inward (Thornhill & Gangestad, 1995). After one orgasm, men typically experience a refractory period, in which they are incapable of reaching another orgasm for several minutes, hours, or even longer. The sexual response cycle and sexual desire are regulated by the sex hormonesestrogen in women and testosterone in both women and in men. Although the hormones are secreted by the ovaries and testes, it is the hypothalamus and the pituitary glands that control the process. Estrogen levels in women vary across the menstrual cycle, peaking during ovulation (Pillsworth,  Haselton, & Buss, 2004). Women are more interested in having sex during ovulation but can experience high levels of sexual arousal throughout the menstrual cycle. In men, testosterone is essential to maintain sexual desire and to sustain an erection, and testosterone injections can increase sexual interest and performance (Aversa et al. Women who are experiencing menopause may develop a loss of interest in sex, but this interest may be rekindled through estrogen and testosterone replacement treatments (Meston & Frohlich,  2000). Although their biological determinants and experiences of sex are similar, men and women differ substantially in their overall interest in sex, the frequency of their sexual activities, and the mates they are most interested in. Men show a more consistent interest in sex, whereas the sexual  desires of women are more likely to vary over time (Baumeister, 2000). Men fantasize about sex more often than women, and their fantasies are more physical and less intimate (Leitenberg Attributed to Charles Stangor Saylor. Men are also more willing to have casual sex than are women, and their  standards for sex partners is lower (Petersen & Hyde, 2010; Saad, Eba, & Sejean, 2009). Gender differences in sexual interest probably occur in part as a result of the evolutionary predispositions of men and women, and this interpretation is bolstered by the finding that gender  differences in sexual interest are observed cross-culturally (Buss, 1989). Evolutionarily, women should be more selective than men in their choices of sex partners because they must invest more time in bearing and nurturing their children than do men (most men do help out, of  course, but women simply do more [Buss & Kenrick, 1998]). Because they do not need to invest a lot of time in child rearing, men may be evolutionarily predisposed to be more willing and desiring of having sex with many different partners and may be less selective in their choice of mates. Women, on the other hand, because they must invest substantial effort in raising each child, should be more selective. The Many Varieties of Sexual Behavior Sex researchers have found that sexual behavior varies widely, not only between men and women but within each sex (Kinsey, Pomeroy, & Martin, 1948/1998; Kinsey,  1953/1998). About a quarter of women report having a low sexual desire, and about 1% of people report feeling no sexual attraction whatsoever (Bogaert, 2004; Feldhaus-Dahir, 2009;  West et al. For about 3% to 6% of the population (mainly men), the sex drive is so strong that it dominates life  experience and may lead to hyperactive sexual desire disorder(Kingston & Firestone, 2008). There is also variety in sexual orientation, which is the direction of our sexual desire toward people of the opposite sex, people of the same sex, or people of both sexes. The vast majority of human beings have a heterosexual orientation—their sexual desire is focused toward members of the opposite sex. Another 1% of the population reports being bisexual (having desires for both sexes).
Acute pyelonephritis per se can cause acute renal failure but this is very uncommon 120mg sildalis fast delivery. The overall interpretation at this point is that she is a medical emergency with acute pyelonephritis in an obstructed urinary tract generic sildalis 120mg on line. This shows stones in both kidneys; the left kidney is reduced in size to 10 cm discount 120 mg sildalis mastercard, with a scar at its upper pole, and is not obstructed; the right kidney is larger at 11 cm but is obstructed as shown by a dilated renal pelvis and ureter; its true size would be less than 11 cm. The immediate management is an intravenous antibiotic to treat Gram-negative bacteria, E. Intravenous fluids should be given (she has vomited) according to fluid balance, carefully observing urine output. The obstruction must be relieved without delay; the method of choice is percutaneous nephrostomy and drainage. In this procedure a catheter is inserted under imaging guidance through the right loin into the obstructed renal pelvis. Not only will this relieve the obstruc- tion but it allows the later injection of X-ray contrast to define the exact site of obstruction (percutaneous nephrostogram). This was done 48 h later and showed hold-up of the contrast at the vesico-ureteric junction, a typical place for a stone to lodge. The patient passed the stone shortly afterwards, as often happens if it is small enough; otherwise it would have to be removed surgically. Blood biochemistry revealed no underlying abnormality to cause the stones: calcium, phosphate, alkaline phosphatase and uric acid were normal. The probable cause of her renal disease is reflux nephropathy because of her sex, history of recurrent infections and the scar on the left kidney. Long-term management comprises prophylactic antibiotics, immediate treatment of acute urinary infections, control of hypertension and regular measurement of renal function. These should be supervised from a fixed base, despite the patient’s peripatetic existence. It settled over the next few hours but there is still a mild ache in the right side on deep breathing. She felt a little short of breath for the first hour or two after the pain came on but now only feels this on stairs or walking quickly. Four years ago something very similar happened; she is not sure but thinks that the pain was on the left side of the chest on that occasion. There is decreased tactile vocal fremitus and the intensity of the breath sounds is reduced over the right side of the chest. Pneumothoraces are usually visible on normal inspira- tory films but an expiratory film may help when there is doubt. There is no mediastinal displacement on examination or X-ray, movement of the mediastinum away from the side of the pneumothorax would suggest a tension pneumothorax. Although she had symp- toms initially, these have settled down as might be expected in a fit patient with no under- lying lung disease. A rim of air greater than 2 cm around the lung on the X-ray indicates at least a moderate pneumothorax because of the three-dimensional structure of the lung within the thoracic cage represented on the two-dimensional X-ray. The differential diagnosis of chest pain in a young woman includes pneumonia and pleurisy, pulmonary embolism and musculoskeletal problems. However, the clinical signs and X-ray leave no doubt about the diagnosis in this woman. Pneumothoraces are more common in tall, thin men, in smokers and in those with underlying lung disease. There is a suggestion that she may have had a similar episode in the past but it may have been on the left side. There is a tendency for recurrence of pneumothoraces, about 20 per cent after one event and 50 per cent after two. Because of this, pleurodesis should be con- sidered after two pneumothoraces or in professional divers or pilots. The immediate management is to aspirate the pneumothorax through the second inter- costal space anteriorly using a cannula of 16 French gauge or more, at least 3 cm long. Small pneumothoraces with no symptoms and no underlying lung disease can be left to absorb spontaneously but this is quite a slow process. Up to 2500 mL can be aspirated at one time, stopping if it becomes difficult to aspirate or the patient coughs excessively. If the aspir- ation is unsuccessful or the pneumothorax recurs immediately, intercostal drainage to an underwater seal or valve may be indicated. Difficulties at this stage or a persistent air leak may require thoracic surgical intervention. This is considered earlier than it used to be since the adoption of less invasive video-assisted techniques. In this woman the apical bulla was associated with a persistent leak and required surgical intervention through video-assisted minimally invasive surgery. Marijuana has been reported to be associated with bullous lung disease, and she should be advised to avoid it. He was unable to look after himself at home because of some osteoarthritis in the hips limiting his mobility. Apart from his reduced mobility, which has restricted him to a few steps on a frame, and a rather irritable temper when he doesn’t get his own way, he has had no prob- lems in residential care. He has been trying to get out of his bed and his chair, and this has resulted in a number of falls. Prior to this he had only been incontinent on one or two occasions in the last 6 months. He thinks that there is a conspiracy in the ward and that the staff are having secret meetings and planning to harm him. He is disorien- tated in place and time although reluctant to try to answer these questions. On a routine blood test 8 years ago he was diagnosed with hypothyroidism and thyroxine 100 mg daily is the only medication he is taking. The staff say that he has taken this regularly up to the last 36 h and his records show that his thyroid function was normal when it was checked 6 months earlier.
Afferent arteriole → Collecting tubule → Glomerulus → Proximal convoluted tubule → Loop of Henle → Distal convoluted tubule d sildalis 120mg for sale. Efferent arteriole → Proximal convoluted tubule → Glomerulus → Loop of Henle → Distal convoluted tubule → Collecting tubule 11 buy sildalis 120mg. Distal convoluted tubules Chapter 12: Filtering Out the Junk: The Urinary System 199 Getting Rid of the Waste After your kidneys filter out the junk discount sildalis 120 mg free shipping, it’s time to deliver it to the bladder. Surfing the ureters Ureters are narrow, muscular tubes through which the collected waste travels. About 10 inches long, each ureter descends from a kidney to the posterior lower third of the bladder. Like the kidneys themselves, the ureters are behind the peritoneum outside the abdominal cavity, so the term retroperitoneal applies to them, too. It also has a middle layer of smooth muscle tissue that propels the urine by peristalsis — the same process that moves food through the digestive system. So rather than trickling into the bladder, urine arrives in small spurts as the muscular contractions force it down. The tube is surrounded by an outer fibrous layer of connective tissue that supports it during peristalsis. Ballooning the bladder The urinary bladder is a large muscular bag that lies in the pelvis behind the pubis bones. There are three openings in the bladder: two on the back side where the ureters enter and one on the front for the urethra, the tube that carries urine outside the body. The neck of the bladder surrounds the urethral attachment, and the internal sphincter (smooth muscle that pro- vides involuntary control) encircles the junction between the urethra and the bladder. When full, the bladder’s lining is smooth and stretched; when empty, the lining lies in a series of folds called rugae (just as the stomach does). When the bladder fills, the increased pressure stimulates the organ’s stretch receptors, prompting the individual to urinate. The male and female urethras Both males and females have a urethra, the tube that carries urine from the bladder to a body opening, or orifice. Both males and females have an internal sphincter con- trolled by the autonomic nervous system and composed of smooth muscle to guard the exit from the bladder. Both males and females also have an external sphincter com- posed of circular striated muscle that’s under voluntary control. The female urethra is about one and a half inches long and lies close to the vagina’s anterior (front) wall. The external sphinc- ter for the female urethra lies just inside the urethra’s exit point. Several openings appear in this region of the urethra, including a small opening where sperm from the vas deferens and ejacu- latory duct enters, and prostatic ducts where fluid from the prostate enters. The membranous urethra is a small 1- or 2-centimeter portion that contains the external sphincter and penetrates the pelvic floor. The cavernous urethra, also known as the spongy urethra, runs the length of the penis on its ventral surface through the corpus spongiosum, ending at a vertical slit at the end of the penis. The and urinary systems is complete in male urethra runs through the the human same “plumbing” as the male reproductive system. The internal sphincter found at the junction of the bladder neck and the urethra is composed of a. Smooth muscle tissue Spelling Relief: Urination Urination, known by the medical term micturition, occurs when the bladder is emptied through the urethra. Although urine is created continuously, it’s stored in the bladder until the individual finds a convenient time to release it. Mucus produced in the blad- der’s lining protects its walls from any acidic or alkaline effects of the stored urine. When there is about 200 milliliters of urine distending the bladder walls, stretch recep- tors transmit impulses to warn that the bladder is filling. Afferent impulses are trans- mitted to the spinal cord, and efferent impulses return to the bladder, forming a reflex arc that causes the internal sphincter to relax and the muscular layer of the bladder to contract, forcing urine into the urethra. The afferent impulses continue up the spinal cord to the brain, creating the urge to urinate. Because the external sphincter is com- posed of skeletal muscle tissue, no urine usually is released until the individual volun- tarily opens the sphincter. Renal artery Chapter 12: Filtering Out the Junk: The Urinary System 203 Answers to Questions on the Urinary System The following are answers to the practice questions presented in this chapter. Irregular sac-like structures for collecting urine in the renal pelvis e Collecting tubule: d. The other answer option can’t be correct because carbon dioxide exits the body through the lungs. Peritoneal refers to the peritoneum, the membrane lining the abdominal cavity; and retro can be defined as “situated behind. Each nephron contains a series of the parts needed to do the kidney’s filtering job. Afferent arteriole → Glomerulus → Proximal convoluted tubule → Loop of Henle → Distal convoluted tubule → Collecting tubule. In short, blood comes through the artery (arteriole) and material gloms onto the nephron before twisting through the near (proximal) tubes, loop- ing the loop, twisting through the distant (distal) tubes, and collecting itself at the other end. Those brush borders provide extra surface area for reabsorption, so it makes sense that they congregate in the first area after filtration. The glomerulus is a collection of capillaries with big pores, so think of it as the initial filtering sieve. These tubules have the most surface area with all those villi brush borders, so they reabsorb the most. The internal sphincter is smooth muscle tissue that prevents urine leakage from the bladder. We go with the guys first because — let’s face it — their biological role in reproduction isn’t as involved as women’s. Then we explain reproduction on the female side of the equation, including a review of the human life cycle from birth to death. But to survive as a species, Ia number of individuals must produce and nurture a next generation, carrying their uniqueness forward in the genetic pool.