By R. Saturas. Voorhees College. 2018.
Phosphate plays a variety of roles in the body: It mainly passive and occurs through the tight junctions aurogra 100mg impotence solutions, is an important constituent of bone; it plays a critical role in driven by the lumen positive potential aurogra 100 mg low cost erectile dysfunction names. Recent studies have cell metabolism, structure, and regulation (as organic phos- identified a tight junction protein that is a channel that fa- phates); and it is a pH buffer. Changes in Mg excretion re- Phosphate is mainly unbound in the plasma and freely sult mainly from changes in loop transport. About 60 to 70% of filtered phos- portions of the nephron reabsorb only a small fraction of phate is actively reabsorbed in the proximal convoluted 2 filtered Mg and, under normal circumstances, appear to tubule and another 15% is reabsorbed by the proximal 2 play a minor role in controlling Mg excretion. Abnormally high tions of the nephron and collecting ducts reabsorb little, if 2 plasma Mg levels have a sedative effect and may cause car- any, phosphate. Only about 5 to 20% of filtered mEq/day; two thirds is excreted in the feces, and one third is phosphate is usually excreted. The kidneys are mainly responsible for important pH buffer and contributes to titratable acid ex- 2 2 regulating the plasma [Mg ]. In Mg -deficient states, limited (see Chapter 23), and the amounts of phosphate fil- 2 Mg virtually disappears from the urine. This is different from the situa- tion for glucose, in which normally less glucose is filtered than can be reabsorbed. If more phosphate is ingested and PHOSPHATE BALANCE absorbed by the intestine, plasma [phosphate] rises, more A normal plasma concentration of inorganic phosphate is phosphate is filtered, and the filtered load exceeds the Tm about 1 mmol/L. The proximal tubule is the major site of limb, is the major site of reabsorption of filtered Mg2. Second, hyperphosphatemia de- of phosphate in the body, they automatically increase creases production of 1,25(OH)2 vitamin D3 in the kidneys phosphate excretion. In cases of phosphate depletion, the by inhibiting the 1 -hydroxylase enzyme that forms this kidneys filter less phosphate and the tubules reabsorb a hormone. With decreased plasma levels of 1,25(OH)2 vita- larger percentage of the filtered phosphate. PTH is of particular im- 2 Low plasma ionized [Ca ] stimulates hyperplasia of the portance; it decreases the phosphate Tm, increasing parathyroid glands and increased secretion of PTH. Patients with chronic renal disease often develop an el- PTH then inhibits phosphate reabsorption by the proximal evated plasma [phosphate] or hyperphosphatemia, de- tubules, promotes phosphate excretion, and helps return pending on the severity of the disease. Elevated PTH levels, the filtered phosphate load is diminished, and the tubules 2 however, also cause mobilization of Ca and phosphate reabsorb phosphate more completely. Increased bone reabsorption results, and the tion is inadequate in the face of continued intake of phos- bone minerals are replaced with fibrous tissue that renders phate in the diet. Hyperphosphatemia is dangerous be- the bone more susceptible to fracture. For example, when calcium phosphate precipitates vised to restrict phosphate intake and consume substances in the walls of blood vessels, blood flow will be impaired. Administration of synthetic 1,25(OH)2 vitamin D3 may com- When plasma [phosphate] rises, the plasma ionized pensate for deficient renal production of this hormone. First, phosphate forms hormone opposes hypocalcemia and inhibits PTH synthesis CHAPTER 24 The Regulation of Fluid and Electrolyte Balance 423 and secretion. Parathyroidectomy is sometimes necessary in Micturition Involves Autonomic patients with advanced chronic renal failure. The urine is trans- hibited or facilitated by higher centers in the brain. The bladder is sic reflexes occur at the level of the sacral spinal cord and specialized to fill with urine at a low pressure and to empty are modified by centers in the midbrain and cerebral cor- its contents when appropriate. Distension of the bladder is sensed by stretch receptors and its sphincters are controlled by the nervous system. This reflex is released by removing inhibitory influ- The Ureters Convey Urine to the Bladder ences from the cerebral cortex. Fluid flow through the ure- thra reflexively causes further contraction of the detrusor The ureters are muscular tubes that propel the urine from and relaxation of the external sphincter. Peristaltic parasympathetic nerve activity stimulates contraction of movements originate in the region of the calyces, which the detrusor and relaxation of the internal sphincter. Sym- contain specialized smooth muscle cells that generate pathetic innervation is not essential for micturition. These pacemaker po- micturition, the perineal and levator ani muscles relax, tentials trigger action potentials and contractions in the shortening the urethra and decreasing urethral resistance.
Nerve conduc- tion is studied in the visual tracts discount aurogra 100 mg with mastercard impotence trials, in the brainstem buy aurogra 100 mg low cost erectile dysfunction books, and through the spinal cord (VEP, BAEP, and SEP). The evidence for immune system involvement in MS is fairly clear while evidence that it is an autoimmune disease is more indirect. Unusually high reactivity of immune system T-cells to proteins of myelin in the CNS (termed antigens since they can trigger immune responses) 2. An over-representation of cells that enhance immune responses (T-helper cells). A relative under-representation of cells that suppress immune responses (suppressor T-cells) 4. The presence of immune system cells in MS lesions in the brain, spinal cord, and optic nerves. Recently, the role of B-lymphocytes that are responsible for producing antibodies has been emphasized. Many studies during the latter part of the twentieth century increased our understanding of the immune system’s reactiv- ity to myelin in MS, including specificity immune responses to myelin antigens. There is an increased susceptibility in certain families in which MS already occurs 2. Some genetically isolated ethnic groups never develop MS (Hutterites in Canada; East European gypsies). The racial differences in MS prevalence are likely to be genetically based. While genetics play a role in MS susceptibility, the nature of the link is both complex and largely unknown. Over the decades, there have been studies of retroviral (HTLV-1, HHV6, and canine distemper), and bacterial (chlamydia pneumoniae, et al. Evidence is anecdotal at this point, with no substantiation in research. Primary progressive MS involves slow worsening from onset and is considered as a single attack. These patients may have to be observed over time; 15% of people with MS show this pattern. Relapsing-remitting MS patients experience neurologic attacks with variable recovery but are clinically stable between attacks. Among this group are a minority of patients who will have minimal disease activity and little or no disability 25 years into their disease. These patients have benign or mild MS and may comprise 10 to 20% of those with MS. Secondary progressive MS is the major progressive form of the disease and accounts for approximately 30% of all MS patients. These patients start with relapsing-remitting disease then slow- ly begin to worsen. By 10 years, 50%, and by 20–15 years at least 80%, of untreat- ed relapsing patients will become secondary progressive. An additional term in the literature, transitional MS, refers to those patients who are evolving into the secondary progressive stage. Some patients begin with no attacks and a progressive course, and later in their disease begin having exacerbations (progressive-relapsing). Clinically isolated syndromes (CISs) are monoregional acute monophasic syndromes that encompass optic neuritis, transverse myelitis, isolated brainstem, or cerebellar syndromes. MRI scans with T2 lesions predict a greater than 80% conversion to MS by 10 years. Have not had any laboratory tests CHAPTER 8: DETERMINING THE DIAGNOSIS AND PROGNOSIS 37 2. Have disease onset at a very early or very late age ADDITIONAL READING Coyle PK. The Nature of Multiple Sclerosis in Advanced Concepts in Multiple Sclerosis Nursing Care. This page intentionally left blank Chapter 9 The Immune System and Its Role in MS Objectives: Upon completion of this chapter, the learner will: Cite normal immune system activity Discuss abnormal immunology involved in MS Describe the rationale for immumodulating MS treatmentsThe immune system protects people from pathogens such as: A. Immunity to certain pathogens; this is common to all healthy individuals 2.
In this procedure buy aurogra 100 mg on-line erectile dysfunction icd 9 code, the semen is diluted with a 10% glycerol purchase 100 mg aurogra visa erectile dysfunction at age of 20, monosaccharide, and distilled water of Semen buffer, and frozen in liquid nitrogen. For some unknown reason, however, not all human sperm is suitable for freezing. Explain the statement that male sexual function is an auto- 1 hour after ejaculation 70% or more nomic synergistic action. Use a flow chart to explain the physiological and physical Leukocyte count 0–2,000/ml events of erection, emission, and ejaculation. Fructose concentration 150–600 mg/100 ml Reprinted with permission of Medical Economics Company from Glaser, L. CLINICAL CONSIDERATIONS Sexual dysfunction is a broad area of medical concern that in- cludes developmental and psychogenic problems as well as con- spurts of semen from the ejaculatory ducts and the urethra. Psychogenic problems of takes place as parasympathetic impulses traveling through the pu- the reproductive system are extremely complex and beyond the dendal nerves stimulate the bulbospongiosus muscles (see fig. Only a few of the principal developmental at the base of the penis and cause them to contract rhythmically. Sexual function in the male thus requires the synergistic action (rather than antagonistic action) of the parasympathetic and sympathetic divisions of the ANS. The mechanism of emis- Developmental Problems of the Male sion and ejaculation is summarized in figure 20. Immediately following ejaculation or a cessation of sexual Reproductive System stimulus, sympathetic impulses cause vasoconstriction of the ar- The reproductive organs of both sexes develop from similar em- terioles within the penis, reducing the inflow of blood. At the bryonic tissue that follows a consistent pattern of formation well same time, cardiac output returns to normal, as does venous re- into the fetal period. Because an embryo has the potential to dif- turn of blood from the penis. With the normal flow of blood ferentiate into a male or a female, developmental errors can re- through the penis, it returns to its flaccid condition. A person with undifferentiated or am- spontaneous emission and ejaculation of semen during biguous external genitalia is called a hermaphrodite. These nocturnal emissions, sometimes called “wet dreams,” True hermaphroditism—in which both male and female are triggered by psychic stimuli associated with dreaming. They are thought to be caused by changes in hormonal concentrations that gonadal tissues are present in the body—is a rare anomaly. Male pseudohermaphroditism occurs more frequently and generally results from hormonal influences during early fetal Semen development. This condition is caused either by inadequate se- Semen, also called seminal fluid, is the substance discharged dur- cretion of androgenic hormones or by the delayed development ing ejaculation (table 20. These individuals have a 46 XY chromosome con- (about 60%) is produced by the seminal vesicles, and the rest stitution and male gonads, but the genitalia are intersexual and (about 40%) is contributed by the prostate. There are usually between 60 and 150 million sperm cells per milliliter of ejaculate. Male Reproductive © The McGraw−Hill Anatomy, Sixth Edition Development System Companies, 2001 Chapter 20 Male Reproductive System 715 The treatment of hermaphroditism varies, depending on the extent of ambiguity of the reproductive organs. Although people with this condition are sterile, they may engage in normal Pelvic sexual relations following hormonal therapy and plastic surgery. The two most 3 Symphysis frequent chromosomal anomalies cause Turner’s syndrome and pubis Klinefelter’s syndrome. About 97% of embryos lacking an X chromosome die; the remaining 3% survive and appear to be Penis females, but their gonads, if present, are rudimentary and do not Scrotum mature at puberty. A person with Klinefelter’s syndrome has an XXY chromosome constitution, develops breasts and male geni- (a) Creek talia, but has underdeveloped seminiferous tubules and is gener- ally mentally retarded. A more common developmental problem than genetic ab- normalities, and fortunately less serious, is cryptorchidism. A cryptorchid testis is usually located along the path of descent but can be anywhere in the pelvic cavity 1 (fig. It occurs in about 3% of male infants and should be treated before the infant has reached the age of 5 to reduce the likelihood of infertility or other complications. The causes of impotence may be physical, involving, for example, ab- normalities of the penis, vascular irregularities, neurological dis- Pelvic cavity orders, or certain diseases.
His plasma (C) Anterior pituitary (E) Skeletal muscle injury osmolality was 370 mOsm/kg H2O (D) Collecting ducts of the kidneys 9 aurogra 100 mg erectile dysfunction divorce. Parathyroid hormone (PTH) (normal buy aurogra 100 mg lowest price what medication causes erectile dysfunction, 281 to 297 mOsm/kg H2O), (A) Decreases tubular reabsorption of plasma [Na ] was 140 mEq/L (normal, (E) Posterior pituitary Ca2 136 to 145 mEq/L), plasma [glucose] 4. A 60-kg woman is given 10 microcuries ( CI) (370 kilobecquerels) (B) Decreases tubular reabsorption of 100 mg/dL (normal fasting level, 70 to of radioiodinated serum albumin phosphate 110 mg/dL), and BUN 15 mg/dL (RISA) intravenously. His most later, a venous blood sample is (D) Secretion is decreased in patients likely problem is collected, and the plasma RISA activity with chronic renal failure (A) Alcohol intoxication is 4 CI/L. Her hematocrit ratio is (E) Secretion is stimulated by a rise in (B) Dehydration plasma ionized Ca2 (C) Diabetes insipidus 0. Aldosterone acts on cortical collecting (D) Diabetes mellitus (B) 625 mL ducts to (E) Renal failure (A) Decrease K secretion 15. Which of the following (D) Increase K secretion changes would be expected? Which of the following leads to decreased Na reabsorption by the (E) Increase water permeability (A) Plasma aldosterone level will rise kidneys? In response to an increase in GFR, the (B) Plasma angiotensin I level will rise (A) An increase in central blood proximal tubule and the loop of Henle (C) Plasma angiotensin II level will rise volume demonstrate an increase in the rate of (D) Plasma bradykinin level will fall Na reabsorption. This phenomenon is (E) Plasma renin level will fall (B) An increase in colloid osmotic called 16. If a person consumes a high-K diet, pressure in the peritubular capillaries (A) Autoregulation the majority of K excreted in the (C) An increase in GFR (D) An increase in plasma aldosterone (B) Glomerulotubular balance urine is derived from level (C) Mineralocorticoid escape (A) Glomerular filtrate (D) Saturation of tubular transport (B) K that is not reabsorbed in the (E) An increase in renal sympathetic nerve activity (E) Tubuloglomerular feedback proximal tubule (continued) CHAPTER 24 The Regulation of Fluid and Electrolyte Balance 425 (C) K secreted in the loop of Henle isotonic saline (0. Renal potassium transport: medullary-collecting duct (C) Plasma arginine vasopressin (AVP) Mechanisms and regulation. Which of the following set of values concentration Physiol 1998;274:F817–F833. Renal Physiol- kg H2O) (mEq/L) kg H2O) explanation for this is that the ogy. Louis: Mosby-Year (A) 300 145 100 (A) Effective arterial blood volume is Book, 2001. New concepts concerning the (C) 285 140 600 (B) Extracellular fluid volume is regulation of renal phosphate excre- (D) 270 130 450 decreased tion. News Physiol Sci (E) 285 140 1,200 (C) Extracellular fluid volume is 1997;12:211–214. Renal magnesium handling: with uncontrolled diabetes mellitus (D) Total blood volume is decreased New insights in understanding old has a plasma [K ] of 4. The body is constantly threatened by acid resulting from (mainly proteins and organic phosphates), and by meta- diet and metabolism. Respiratory acidosis is an abnormal process characterized lungs, and the kidneys. The concentration ratio (base/acid) of any buffer diminishing the severity of the acidemia. The bicarbonate/CO buffer pair is effective in buffering in compensate by increasing the excretion of filtered HCO , 2 3 the body because its components are present in large thereby, diminishing the alkalemia. The respiratory system influences plasma pH by regulating by a gain of acid (other than H CO ) or a loss of HCO. The Respiratory compensation is hyperventilation, and renal kidneys influence plasma pH by getting rid of acid or base compensation is an increased excretion of H bound to uri- in the urine. Metabolic alkalosis is an abnormal process characterized tion of filtered HCO , excretion of titratable acid, and by a gain of strong base or HCO or a loss of acid (other 3 3 excretion of ammonia. Respiratory compensation is hypoventilation, 3 2 3 plasma and replenishes depleted HCO when titratable and renal compensation is an increased excretion of 3 acid (normally mainly H PO ) and ammonia (as NH ) HCO. The stability of intracellular pH is ensured by membrane [HCO ] and is most useful in narrowing down possible 3 transport of H and HCO , by intracellular buffers causes of metabolic acidosis. For example, the in extracellular fluid because ECF is easier to analyze than [H ] of arterial blood is normally 35 to 45 nmol/L (pH intracellular fluid and is the fluid used in the clinical eval- 7.
Space Cadets Corner featuring:
Ares: US space program - talk by Hall and Jenkins 9/06
Asteroid Dreams - Astra's story about asteroid exploration