Treating Adrenal Exhaustion
The furrowed surface of the adrenal gland (suprarenal gland) is encased in a vascularized connective tissue capsule H .The adrenal gland consists of the cortex 2 and the medulla O. The zona reticularis H of the cortex is emphasized as a heavily stained dark band. This band makes the border between cortex and medulla particularly obvious in this preparation. A large muscular vein 0 in the medulla is cut (cf. Fig.357). o Cortex and medulla are of different phylogenetic origin and have distinct o functions within the organ.
The adrenal glands are enclosed within the perinephric fascia and are usually surrounded by a sufficient amount of fat for identification on computed tomography (CT) or magnetic resonance imaging (MRI). The right adrenal gland lies immediately posterior to the inferior vena cava (IVC). The left adrenal gland lies anteromedial to the upper pole of the left kidney and posterior to the pancreas and splenic vessels. The shape of the adrenals can vary, depending on the orientation of the gland and the level of the image, but the normal adrenal gland has an arrowhead configuration, with a body and medial and lateral limbs. The normal adrenals extend over 2-4 cm in the cranio-caudal direction, and on CT the thickness of the normal adrenal body and limbs does not exceed 10-12 and 5-6 mm, respectively 8 .
The adrenal gland is a richly vascularized organ. There are connections between the vascular networks of the cortex and medulla. Having passed the medullary sinuses, the venous blood accumulates in the throttling veins, which are characterized by irregularly arranged subendothelial longitudinal muscle strands (muscle cushions). In some places, very strong underlying muscles may cause the venous walls to bulge into the lumen. The contraction of muscles underneath the tunica intima presumably throttles the blood flow in the capillaries, which supply the surrounding tissue. The figure shows a throttling vein in the adrenal medulla and its powerful muscle bulges . Note the cross-sectioned smooth muscle cells. The muscle cells run parallel to the longitudinal axis (cf. Figs. 284, 285).
The cardiovascular system becomes depressed, leading to depression of the vasomotor center in the brain and to hypotension. Conversely, in some individuals, intoxication causes the release of catecholamines from adrenal glands, which leads to hypertension. Intoxication depresses leukocyte movement into areas of inflammation, depresses platelet function, and leads to fibrinogen and clotting factor deficiency, thrombocytopenia, and decreased platelet function.
Plasma volume contraction cardiovascular volume receptors Fall in arterial blood pressure cardiovascular baroreceptors Hormonal beta-adrenergic stimulation angiotensin II hypothyroidism hypoadrenalism Drugs nicotine barbiturates vincristine Miscellaneous nausea and vomiting hypoglycaemia stress heat
Oo Small lipid inclusions are particularly abundant in cells from steroid hor- 3 mone-producing glands. This figure shows cells from the zona fasciculata of the adrenal gland. The cells are densely populated with small vacuoles, which correspond to small lipid droplets. With suitable fixation methods, these lipid droplets remain intact, and they can then be stained with lipo-philic dyes. At the time of preparation, other fatty substances were removed from the tissue. This accounts for the holes in these large round or polygonal cells and explains the name spongiocytes. Between fat vacuoles, the delicate cytoplasmic septa and cytoplasmic bridges (stained blue) are preserved (see Figs. 351-354). Note the intensely stained cell nuclei (blue) , their clearly visible nucleoli, and the abundance of capillaries 2.
In the liver and adrenal gland, the activity of EPHX1 was three times higher than that observed in the kidney and lung and could be observed as early as 8 weeks' gestation (Table 4). At 22 weeks, EPHX1 activity had increased to about half that observed in adult liver. EPHX2 is also expressed in the fetus, although fewer ontogenic studies have focused on this isoform. EPHX2 activity was demonstrated as early as 14 weeks in fetal liver with no change in activity occurring with time.25 Adult hepatic activity of EPHX2 was fivefold higher than that observed in the fetus. However, additional studies are needed to examine the change in activity between 30 weeks' gestation and 30 years of age. EPHX2 is also observed in extrahepatic fetal tissue, including the kidney, adrenal glands, intestine, and lungs, but developmental expression in these tissues was less evident.90
CRF is synthesized in the hypothalamus and elicits the release of adrenocorticotropic hormone (ACTH) from the pituitary. CRF was isolated from sheep hypothalamus and its structure as a 41-amino-acid peptide determined.96 The hypothalamic paraventricular nucleus (PVN) is the major region in the brain of CRF-containing cell bodies and through axonal projections to the capillaries of the median eminence can secrete CRF directly into the portal system where it acts at the pituitary to regulate ACTH secretion into the circulation. The principal role of ACTH is to stimulate the release of cortisol from the adrenal gland, thus completing the HPA axis, a primary component of the neuroendocrine response to stress. Similarly, projections from the PVN to the lower brainstem and spinal cord have been demonstrated to regulate autonomic function and help to further mediate the behavioral responses to stress. High densities of CRF-containing neurons are localized in particular to prefrontal,...
The laboratory rat has been, and continues to be a mainstay of biomedical research. Both albino and pigmented animals are available. There are recognized differences between wild and laboratory rodents. For example, laboratory rats have smaller adrenals and preputial glands, earlier sexual maturity, no reproductive cycle seasonability, better fecundity, and a shorter life span than their free-ranging wild counterparts.
A high serum androgen value may suggest the diagnosis of polycystic ovary syndrome or may suggest an androgen-secreting tumor of the ovary or adrenal gland. Further testing for a tumor might include a 24-hour urine collection for cortisol and 17-ketosteroids, determination of serum 17-hydroxyprogesterone after intravenous injection of corticotropin (ACTH), and a dexamethasone suppression test. Elevation of 17-ketosteroids, DHEA-S, or 17-hydroxyprogesterone is more consistent with an adrenal, rather than ovarian, source of excess androgen.
Doctors are not sure exactly how physical and mental health influence each other, but growing scientific evidence suggests that the mind body connection is real. For example, the so-called fight or flight response, in which the nervous system and the adrenal glands flood the body with the hormone adrenaline when you are frightened, increases both heart rate and blood flow to the muscles. This response prepares the body to deal with apparent danger. In this case, the survival response is helpful.
Ably around 106 neurons are in the hypothalamus, and this region controls a wide diversity of clearly definable functions that are much more amenable to experimental investigation. Different neuronal groups in the hypothalamus control the release of different hormones from the pituitary gland - oxytocin vasopressin prolactin growth hormone the gonadotrophic hormones adrenocorticotrophic hormone (that in turn controls steroid secretion from the adrenal glands) thyroid stimulating hormone (that controls the functions of the thyroid gland) and melanocyte-stimulating hormone. The hypothalamus also controls thirst, feeding behavior (including specific appetites such as sodium appetite), body composition, blood pressure, thermoregulation, and much instinctive or reflex behavior including male and female sexual behavior and maternal behavior. These functions involve highly specialised cells with specific properties cells for instance that have receptors or intrinsic properties that enable...
Burkitt lymphoma occurs endemically in children in the lymphoma belt'' of Central Africa and in Papua. The incidence peaks at 4-8 years of age with a male female ratio of 2 1. Sporadic cases are seen in children and young adults throughout the rest of the world (2,3). It is also seen in association with HIV induced immunodeficiency (4). Because BL is so common in Africa, it accounts for 30-50 of all childhood lymphomas. In the United States and Europe, it makes up only 1-2 of all B-cell lymphomas. The most frequently involved sites are the jaws, ovaries, testes, thyroid, adrenals, and breasts, i.e., tissues that are comparatively poor in lymphoreticular elements. Patients present with large tumors due to the high proliferation rate and rapid growth of BL (Fig. 1). The skin may show secondary involvement (5) or indicates relapse of BL (6,7).
Early reports were enthusiastic about the ability of MRI to differentiate benign from malignant adrenal masses on the basis of signal intensity (SI) differences on T2-weighted spin-echo images. In general, metastases and carcinomas have a higher fluid content than adenomas and therefore are of higher SI on T2-weighted images than the surrounding normal adrenal gland. Adenomas are homogeneously iso- or hypo-intense compared with the normal adrenal gland. However, considerable overlap exists between the signal intensities of adenomas and other lesions, and up to 31 of lesions remain indeterminate 16-18 .
Whole body positron emission tomography (PET) with 18-F-fluorodeoxyglucose (18-FDG) allows malignant adrenal lesions to be recognized. The contribution of 18-FDG PET has been well evaluated in large studies in relation to lung cancer, and is highly accurate in differentiating benign non-inflammatory lesions from malignant disease. Using 18-FDG PET, these studies have shown a 100 sensitivity and specificity for the diagnosis of malignant adrenal mass when CT or MRI identify enlarged adrenal glands or a focal mass. Recent studies have reported false positive results as a result of 18-FDG uptake by pheochromocytomas and benign adenomas. For the diagnosis of a malignant adrenal tumour, the positive predictive value of 18-FDG PET was 100 and the negative predictive value (NPV) to rule out malignancy was also 100 . Within these study populations, 18-FDG PET also has the ability to detect metastatic lesions in non-enlarged adrenal glands, but its accuracy in this situation has not been fully...
The restricted fate of different neural crest cell precursor populations along the neuraxis (see Table 1) has been extensively tested in avian embryos using the quail-chick chimera technique. Neural fold fragments from one axial level of quail donor embryos were grafted into different axial levels of chick host embryos (reviewed in Le Douarin and Kalcheim, 1999). These experiments revealed that, in general, neural crest cell precursors from all axial levels are plastic, as a population that is, a premi-gratory population from one axial level can form the neural crest cell derivatives characteristic of any other axial level. For example, caudal diencephalic neural crest precursors, which do not normally form neurons or glia, will contribute appropriately to the parasympathetic ciliary ganglion and proximal cranial sensory ganglia after grafts to the mesencephalon or hindbrain (Noden, 1975, 1978b). Trunk neural crest precursors, which do not normally form enteric neurons, will colonize...
The two deaths reported by Steinschneider that form the basis for the contention that apneic episodes are associated with SIDS cases involved a brother and sister. In addition to these two deaths, mention is made in the article that three other children in the family had also died. The first male developed recurrent cyanotic spells and died suddenly at 102 days of age the second, a female, turned blue and died at 48 days of age. Neither of the two children was autopsied. The third cried out and died suddenly at 28 months of age. An autopsy was negative, except for the fact that the adrenal glands were considered to be of small size.
An exception to this general arrangement of the sympathetic division is that of the adrenal medulla. The adrenal gland lies above the kidney, and is structurally two separate organs. The outer shell of the adrenal gland is concerned with production of the steroid hormones, while the inner core is the adrenal medulla, a modified sympathetic ganglion. Thus, pregan-glionic cholinergic fibers run to the adrenal medulla, where they synapse with postganglionic cell bodies, which are in effect hormone-secreting cells. These cells respond to the arrival of impulses down the preganglionic fibers, by secreting the catecholamine hormones epinephrine and norepinephrine into the bloodstream.
Schematic showing trunk neural crest cell migration pathways and derivatives (also see Fig. 1C). Neural crest cells migrate ventrally through the sclerotome to form neurons and satellite glia in the dorsal root ganglia and sympathetic ganglia, chromaffin cells in the adrenal gland (and Schwann cells on the ventral root not shown). Neural crest cells also migrate dorsolaterally beneath the epidermis to form melanocytes. nc, notochord nt, neural tube. FIGURE 5. Schematic showing trunk neural crest cell migration pathways and derivatives (also see Fig. 1C). Neural crest cells migrate ventrally through the sclerotome to form neurons and satellite glia in the dorsal root ganglia and sympathetic ganglia, chromaffin cells in the adrenal gland (and Schwann cells on the ventral root not shown). Neural crest cells also migrate dorsolaterally beneath the epidermis to form melanocytes. nc, notochord nt, neural tube.
These observations led us to the hypothesis that ketoconazole administration on a long-term basis might slow the progression of renal failure. One problem with this concept is the well-known escape phenomenon When cortisol production is inhibited, adrenocorticotrophic hormone (ACTH), derived from the pituitary gland, increases and stimulates the adrenal gland to produce more cortisol. We have found that this escape can be prevented by administering a low dose (2.5 mg per day) of prednisone (a synthetic glucocorticoid) at the same time. ACTH levels do not rise, and the block in cortisol synthesis persists.
Pheochromocytoma is a rare tumor, most often located in the adrenal gland, that arises from catecholamine-producing chromaffin cells. Although pheochromocytoma occurs in only 0.1 to 0.3 of all hypertensive patients, hypertension may be fatal if the pheochromocytoma goes unrecognized. These tumors secrete large quantities of epinephrine and norepinephrine, resulting in persistent or paroxysmal hypertension. Pheochromocytomas are vascular tumors that contain hemorrhagic or cystic areas and are most often well encapsulated, with 90 of the tumors being benign. The tumors are generally less than 6 cm in diameter and usually weigh less than 100 g.
Throughout the time the patient is under your care, monitor serial blood pressures to determine if high or low levels occur. Monitor the heart rate and rhythm, assessing for sinus tachycardia and other cardiac dysrhythmias. Avoid palpation over the bladder or deep palpation of the kidneys and the adrenal gland, which can lead to a severe hypertensive attack.
In cases such as the aforementioned, most deaths are caused by the combined effect of the physiological consequences of violent physical activity and the effects of the drugs. During high intensity exercise, e.g., a struggle, there is release of catecholamines (norepinephrine and epinephrine) from the adrenals into the circulation. The effects of these substances are to increase the rate and force of contraction of the heart, the conduction velocity and the blood pressure. This results in an increase in demand for oxygen by the heart. The highest levels of catecholamines occur not during physical activity (a struggle in this case) but approximately 3 min after cessation of the activity.1,2
The rest of the abdomen is 'filled' with the liver and the spleen, both appearing as homogenous triangular structures. The adrenals are triangular hypoechoic masses located on the top of the kidney. The pancreas and the abdominal vessels complete the evaluation of the fetal abdomen. The adrenals are large and display a corticomedullary differentiation 1, 2 .
Lesions also have more profound effects on food intake, particularly in females. Neurons of the VMH are selectively activated by the ovarian hormone, estrogen, and in female rats the cells respond by producing progesterone receptors. This does not occur in the male VMH. In primates, the hormonal signal may be somewhat different because loss of the adrenal glands, a source of androgen hormones, leads to reduction in copulatory behavior. Although there is little difference in the absolute size of the VMH, there is some reason to believe that it becomes sexually dimorphic during development (Sakuma, 1984). Estra-diol and testosterone have a dramatic affect on both neurite outgrowth and dendritic branching in organ-otypic cultures of the mouse hypothalamus (Toran-Allerand, 1980 Toran-Allerand et al., 1983).
Depending on the stage, surgical intervention and further staging is the primary treatment for renal cell cancer. A radical nephrectomy (removing the whole kidney, the attached adrenal gland, and fatty tissue that surrounds the kidney), sometimes with lymph node removal, offers the patient the best chance for cure. The procedure is the treatment of choice for localized cancer or in patients with tumor extension into the renal vein and vena cava. Surgical intervention is not curative for disseminated disease. Because of the proximity of the kidney to the diaphragm, the surgeon may explore the pleura on the surgical side. The patient could therefore return from surgery with a chest tube placed to remove blood and air from the pleural space. A partial nephrectomy is reserved for those patients with very small renal cell tumors, those who have cancer in both kidneys, or those who only have one kidney.
The endogenous nucleoside adenosine exerts a variety of physiological effects via interactions with a family of G protein-coupled receptors consisting of four subtypes the adenosine A A2A, A2B, and A3 receptors.49 The A1 receptor is the most comprehensively studied adenosine receptor subtype and has been cloned from a number of species, including humans. Ai receptors are believed to act mainly via the Gi o family of G proteins and are widely expressed in the brain, spinal cord and a variety of peripheral tissues such as adipose tissue, heart, eye, adrenal gland, liver, kidney, salivary glands, and GI tract.49 Despite this widespread distribution, A1 knockout mice develop normally and display relatively subtle differences compared to wild-type animals, suggesting that adenosine A1 receptors are particularly important under pathophysiological conditions.50
Hormone levels play a role in men's sexual expression, and changes in hormone levels may account for some of the age-related changes in sexuality. Testosterone is the key hormone that regulates sexual response in men and has some effect in women. Testosterone is produced by the adrenal glands, testicles, and ovaries. Women produce less than a tenth of the amount produced by men. Testosterone levels in men are highest in the morning right after waking and decrease throughout the day, so blood tests for testosterone are taken before 9 00 am for accuracy. After a rise during adolescence, testosterone production declines throughout life in men. Much less is known about age-related production of testosterone in women.
Animals were regularly weighed and inspected to follow their growth and general well-being. Also, survival of animals was followed. An autopsy was performed on all rats that died naturally, whenever possible within 24 hours. A total of 31 treated and 29 control rats were autopsied. An autopsy included a macroscopic evaluation of skin, internal tumors, and pathology. After macroscopic evaluation, samples were taken of heart, liver, kidney, lung, hypophysis, adrenals, and tumors for later microscopic examination. This included a normal pathological examination of tissues as carried out by a pathologist. A fluorescence histochemistry of adrenal gland and superior cervical ganglia was carried out to estimate lipopigment accumulation. This was determined by a quantitative fluorescence microscopy as described in detail elsewhere.27 Briefly, the fixed tissues were embedded in paraffin, sectioned serially, and examined under a Nikon Mikrophot FXA fluorescence microscope. Quantitation of...
Renal agenesis may also be mimicked by a multicystic dysplastic malformation of the kidney later in life since the multiple cysts seen in the affected infant disappear with time. In 10 of cases unilateral renal agenesis is associated with aplasia of the ipsilateral adrenal gland. In all other cases a characteristic elongated feature of the adrenal gland is found. Bilateral renal agenesis (Potter syndrome) is incompatible with life and most infants die shortly after birth.
Upon commencement of high-intensity physical activity (a struggle in these cases), the adrenal glands secrete epinephrine and norepinephrine into the blood. Most of the alpha adrenergic receptors on effector organs (cardiac muscle, smooth muscle) are alpha-1 receptors. Stimulation results in smooth muscle contraction of blood vessels, with resultant vasospasm. The beta-1 receptors are primarily in the heart the beta-2 receptors in the heart and peripherally. Stimulation of the beta-1 receptors causes an increase in heart rate, contractility and conduction velocity. Beta-2 stimulation results in smooth muscle relaxation. Epinephrine reacts with alpha and beta receptors both peripherally and in the cardiovascular system. Norepinephrine has its predominant effect on the cardiovascular system, reacting with the alpha-1 and beta-1 receptors in the effector cells of the heart. Thus, both epinephrine and norepinephrine react with beta-1 receptors with resultant increase in heart rate,...
Aldosterone is secreted from the zona glomerulosa of the adrenal gland in response to hyperkalemia, circulating angiotensin II, surgery, physical trauma, hemorrhage, or anxiety. It stimulates sodium retention and potassium and hydrogen ion secretion in the distal convoluted tubule of the kidney and promotes sodium absorption by the intestinal mucosa, sweat glands, and salivary glands.
Early studies on P450 enzymes focused on the liver as the main drug-detoxifying organ and the adrenal gland for the metabolism of endogenous substrates, but it was soon recognized that other organs, notably those that serve as portals of entry to the body, such as the respiratory and the gastrointestinal tracts, also express P450s and other biotransformation enzymes. Each organ or tissue has its own profile of P450 enzymes that will determine the sensitivity of that tissue to a xenobiotic. It should be noted that most extrahepatic P450 enzymes are also present in the liver, often at a higher concentration, but can be regulated differently in different tissues, leading to altered xenobiotic exposures. Table 3 summarizes the tissue distribution of P450 enzymes that are commonly detected at either the mRNA (or, less commonly, the protein) level in various human organs.
The aim of the first case study was to elucidate pathways downstream of the corticotropin-releasing factor (CRF) receptor CRF1 in order to identify novel modulators of this receptor-signaling pathway.16 CRF is a 41-amino-acid polypeptide that plays a central role in the regulation of the hypothalamic-pituitary-adrenal (HPA) axis, mediating neuroendocrine, autonomic, and behavioral responses to various stressors.17 Hypothalamic neurons release CRF in response to stress, stimulating the secretion of adrenocorticotropic hormone (ACTH) from the pituitary, which in turn leads to increased release of glucocorticoids from the adrenal glands. Alterations in the CRF system activity have been linked to a number of psychiatric disorders, including anxiety and depression. Since the pituitary is the main target organ for CRF, the study was performed on a mouse pituitary-derived cell line called AtT-20 that expresses the CRF1 receptor. Experimenting on freshly isolated pituitary cells probably...
The effects that HCB has on immune system development in the rat were reported in studies by Vos et al. (1979a 1983). Pregnant Wistar rats received diets containing 50 or 150 mg HCB kg starting on day 1 to 3 of pregnancy and through gestation and lactation. Pups were weaned after PND 21 and continued on the same HCB dose as their dams for an additional 2 weeks prior to testing at 5 weeks of age (Vos et al. 1979a). Either male or female offspring, but not both, were evaluated for alterations in immune endpoints. The weight of the adrenal glands and livers of female pups exposed to 150 mg HCB kg was increased, as were total serum IgM and IgG concentrations. Body, spleen, and thymus weights of females were not different from controls. In both dosage groups, males infected with Listeria mono-cytogenes displayed reduced resistance to this bacterial infection, as did a separate set of males infected with Trichinella spiralis . In both dosage groups, females had increased IgM and IgG...
Low density lipoproteins (LDL) contain a high concentration of cholesterol and cholesterol esters and are involved in the transport of dietary and endogenous cholesterol. Cholesterol is delivered from the liver to peripheral tissues, especially adipose tissue and the adrenal glands, and also returned to the liver. High density lipoproteins (HDL) HDL2 and HDL3 involved in the return of cholesterol from peripheral tissues to the liver (reverse transport).
Since IV-BCL is a systemic disease with widespread dissemination, thorough staging investigations are mandatory early in the course of the disease. Special emphasis has to be addressed to the involvement of the central nervous system, the lung, kidney, and adrenals (15). Multiagent chemotherapy (CHOP) is the standard treatment (16). Successful treatment with high-dose chemotherapy and autologous peripheral blood stem cell transplantation (17) or autologous bone marrow transplantation (18) has been reported.
The kidneys are situated in the posterior part of the abdomen on either side of the vertebral column behind the peritoneum. The right kidney is usually slightly lower than the left. The posterior surface and upper portion of the right kidney rest on the 12 th rib the left kidney usually rests on the 11th and 12 th ribs. The anterior surface of the right kidney is in contact with the right adrenal gland, liver, and the right colic flexure. The anterior surface of the left kidney is in contact with the left adrenal gland, stomach, spleen, jejunum, colon, and, medially, the pancreas.
Anemia, leukopenia, thrombocy-topenia. Pulmonary Bronchopul-monary dysplasia with interstitial pulmonary fibrosis. Ophthalmologic Cataracts after prolonged use. Der-matologic Hyperpigmentation, especially in clients with a dark complexion also, urticaria, erythema multiforme, erythema nodosum, alopecia, porphyria cutanea tarda, excessive dryness and fragility of the skin with anhidrosis, dryness of the oral mucous membranes, cheilosis. Metabolic Syndrome resembling adrenal insufficiency, including symptoms of weakness, severe fatigue, weight loss, anorexia, N&V, and melanoderma (especially after prolonged use). Also, hyperuricemia and hyperuricosuria in clients with chronic myelogenous leukemia. Oral Dry mouth, stomatitis, cheilosis. Miscellaneous Cellular dysplasia in various organs, including lymph nodes, pancreas, thyroid, adrenal glands, bone marrow, and liver. Also, gynecomastia, seizures after high doses, cataracts after prolonged use, hepatotoxicity, cholestatic jaundice,...
Most adrenal neoplasms are amenable to laparoscopic approach because of small size and benign nature. The right adrenal gland is pyramidal in shape and lies superior to the right kidney. Laparoscopic right adrenalectomy is easier than left adrena-lectomy but can be more hazardous due to shorter adrenal vein that empties into the vena cava. The left adrenal gland is more flattened and in intimate contact with the medial aspect of the superior pole of left kidney. The key to laparoscopic resection is complete division of the splenorenal ligament superiorly to the diaphragm and mobilization of the spleen medially.
Adrenal glands Adrenal glands Hypothalamus. The hypothalamus is the region of the brain that coordinates production and release of hormones by the pituitary gland, the thyroid gland, the adrenal glands, and the testicles. Adrenal glands. The adrenal glands produce corticosteroid hormones, which 365 have an important role in metabolism epinephrine, which helps your body Endocrine respond to stress or danger aldosterone, which helps regulate your blood system pressure and the sodium and potassium levels in your blood and testosterone,
Following cessation of a violent struggle, the levels of catecholamine continue to increase for approximately three minutes, while the level of potassium drops dramatically.1-5 These two factors predispose to the development of an arrhythmia. This is the time of post exercise peril described by Dimsdale.1 Stimulants such as cocaine and methamphetamine can cause excited delirium. If the individual has taken amphetamine, cocaine or another stimulant, the physiologic effects of the struggle can be magnified by the drugs and a fatal arrhythmia more readily ensue. Cocaine has a double effect. It causes increased release of catecholamines from the adrenals and inhibits norepinephrine reuptake. The latter action causes norepinephrine to accumulate at the neu-roeffector junction, intensifying its effect. Thus, by these actions, cocaine works on the beta-1 receptors to increase heart rate, force of contraction and
Cancer which arises from neural crest cells, which most commonly occur in preschool aged children. Tumor location may be the adrenal glands, neck, pelvis, mediastinum, or any other place where sympathetic ganglion cells are located. It usually presents as an asymptomatic abdominal mass. Workup includes CT and ultrasound, followed by possible BM biopsy and radionuclide scanning. Laboratory evaluation includes blood and urine levels of VMA and HVMA. The most effective treatment is surgical excision.
The left adrenal gland is frequently crescent-shaped. The left adrenal gland often extends relatively far downward toward the renal hilum. 189 Layers of adrenal gland 189 Layers of adrenal gland 190 Layers of adrenal gland 190 Layers of adrenal gland The adrenal gland is seen to consist of three layers two echodense outer layers and a hypoechoic middle layer.
The RAS contributes to the development and maintenance of hypertension and mediates renal injury by inducing systemic and glomerular hypertension. Synthesis of angiotensin II (AT-II) depends on the release of renin, primarily by juxtaglomerular cells in the kidney (Figure 5). The release of renin is regulated by the hydrostatic pressure sensed at the glomerular afferent arterioles, AT-II levels, and the quantity of sodium delivered to the macula densa. Plasma potassium, atrial natriuretic peptide, and endothelin levels also affect renin synthesis and release. Renin acts to cleave the liver angiotensinogen to angiotensin I (AT-I). ACE then converts AT-I to AT-II. This proteolytic enzyme is found in the endothelial cells of the lung, vascular endothelium, and cell membranes of the kidneys, heart, and brain. ACE also degrades vasodilator bradykinin to inactive fragments. Non-renin and non-ACE pathways also exist in the body allowing the production of AT-II either directly from...