Term
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Definition
| portion of the sphenoid bone called sella turcica |
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Term
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Definition
| roof of the pituitary gland is formed by a reflection of the dura attached to the clinoid processes. prevents cerebrospinal fluid from entering the sella turcica. pituitary stalk passes through an opening in this diaphragm. 500-900mg |
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Term
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Definition
| somatotrophs,mammotrophs, corticotrophs,thyrotrophs,gonadotrophs |
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Term
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Definition
| contains non-myelinated axons of neurosecretory cells, which are supported by pituicytes. |
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Term
| Blood supply of pituitary gland |
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Definition
| internal carotied, superior, inferior middle hypophysial arteries |
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Term
| Posterior Lobe Pituitary gland |
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Definition
| is supplied directly from branches of the middle and inferior hypophisal arteries. |
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Term
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Definition
| superior hypophisal artery form capillary network in the median eminence of hypothalamus that recombines in long portal veins draining down the pituitary stalk to anterior lobe. |
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Term
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Definition
| venous channels drain via cavernous sinus posteriorly to superior and inerior sinuses to the jugular vein. |
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Term
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Definition
| allows control of anterior pituitary function by the hypothalamic hypphysiotropic hormones secreted into the portal hypophysial vessels. |
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Term
| Posterior Pituitary Hormones |
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Definition
| vasopressin and oxytocin, are not regulated by releasin hormones. synthesized in hypothalamus transported to posterior pituitary and released in response to specific signals. |
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Term
| Synthesis locations of Posterior Pituitary Hormones |
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Definition
| supraoptic nuclei and lateral and superior parts of paraventricular nuclei. transported to posterior pituitary and released in response to specific physiologic signals, such as high plasma osmolarity. |
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Term
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Definition
| Arginine vasopressin produced in supraoptic and paraventricular nuclei of hypothalamus and it is stored in posterior part of pituitary gland. some released directly into brain. related to oxytocin. |
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Term
| Receptor types of Arginine Vasopressin |
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Definition
| V1-vasoconstriction in vascular smooth muscle in the skin, gluconeogenesis in liver. V-2 kidney it is mediated via binding ov AVP to G protein-coupled V2 receptors on surface of cell of the collecting tubules, activation of adenyl cyclase and insertion into luminal surface of water channels composed of aquaporin 2 increasing water permeability and resorbtion. Vasopressin treats diabetes insipidus. |
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Term
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Definition
| implicated with memory formation. released into the brain in circadian rhythm by neurons of suprachiasmatic nucleus of hypothalamus. caution with coronary heart disease. |
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Term
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Definition
| 1. secretion regulated by osmotic pressure. osmoreceptors in hypothalamus. extremely sensitive to small chanes in plasma concentration of Na. 2. Acute changes in blood volume/pressure. Neuronal afferents in transmural pressure receptors of cardiac atria, aorta, and carotid arteries; project via vagus glossopharyngeal nerves to nucleus tractus of brain stem; ascend to paraventricular supraoptic. 3. nausea, hypoglycemia, glucocorticoid. |
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Term
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Definition
| essential to prevent hypertonic dehydration. regulated by osmostat located in anteromedial hypothalamus and able to detect very small changes in plasma concentration of sodium and other effective solutes. |
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Term
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Definition
| caused by lack of ADH called Central Diabetes Insipidus. Caused by failure of kidneys to respons to ADH, called nephrogenic diabetes insipidus. |
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Term
| Etiology of Central Diabetes Insipidus |
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Definition
| damage to hypothalamus or pituitary as result of surgery; hypophysectomy(complete or partial); infection; tumor or cysts (intra-and suprasellar), or head injury; autoimmune. |
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Term
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Definition
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Term
| Etiology Nephrogenic Diabetes Insipidus |
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Definition
| diseases of kidney, chronic renal disease: any renal disease that interferes with collecting duct or medullary function; effects of certain drugs; hypokalemia; congenital defect. |
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Term
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Definition
| hypernatremia(increased blood sodium content), polyuria(excess urine production), polydipsia(thirst), nocturia |
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Term
| Treatment of Central Diabetes Insipidus |
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Definition
| may be controlled with vasopressin(desmopressin). administered as either a nasal spray or tablets. ineffective for patients with nephrogenic DI. |
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Term
| Medication causing diabetes insipidus |
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Definition
| (lithium) stops medication leads to recovery of normal kidney function. |
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Term
| Adipsic Hypernatremia Etiology |
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Definition
| caused by agenesis or destruction of hypothalamic osmoreceptors that normally regulate thirst and AVP secretion. deficiency can usually be traced to an identifiable congenital or acquired disease in the hypothalamus. |
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Term
| Pathophysiology Adipsic Hypernatremia |
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Definition
| lack of thirst and failure to drink enough water to replenish renal and extrarenal losses decrease total-body water and decrease plasma osmolality/sodium. Plasma renin activity and aldosterone secretion increase, and plasma potassium fall to urinary excretion. |
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Term
| Clinical Signs and symptoms of Adipsic Hypernatremia |
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Definition
| characterized by chronic or recurrent hypertonic dehydration and a deficient AVP response to osmotic stimulation. Little or no thirst. Hypovolemia such as tachycardia, hypotension, hypokalemia, acute renal failure. |
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Term
| Treatment of Adipsic Hypernatremia |
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Definition
| administering water by mouth, if patient alert, .45% saline by vein. |
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Term
| Etiology of Syndrome of Inappropriate Antidiuretic Hormone |
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Definition
| can be caused by a primary defect in AVP secretion or action can be secondary to a recognized nonosmotic stimulus such as hypovolemia, hypotension, glucocorticoid deficiency. |
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Term
| Clinical Signs and symptoms |
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Definition
| water intoxification that may include mild headache, confusion, anorexia, nausea, vomiting, coma, convulsions. sever hyponatremia. |
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Term
| Treatment of Syndrome of Inappropriate Antidiuretic Hormone |
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Definition
| Acute is to restrict total fluid intake to less than the sum of insensible losses and urinary output. Total should include water derived from food. Insensible losses in adults usually approximate 500ml/d total discretionary intake should be at least 500 ml less than urinary output. deficit reduces body water and increases serum sodium by about 1-2% per day. chronic hypoatremia minimized by treatment with demeclocycline, 150 to 300 mg orally 3-5 times a day |
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Term
| Oxytocin Productino center |
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Definition
| magnocellular neurosecretory cells in supraoptic nucleus and paraventricular nucleus of hypothalamus and released into blood from posterior pituitary. paraventricular nucleus releases it to other locations. |
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Term
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Definition
| a peptide of nine amino acids. molecular mass of 1007 daltons. One IU of this is equivalent of about 2 micrograms of pure peptide. half life is .55 to 3.6 minutes. |
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Term
| Oxytocin actions in brain |
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Definition
| plasma concentrations of oxytocin have been reported to be higher amongst people who claim to be falling in love. role in social behaviors in humans. deficiencies may be feature of autism. increases trust. |
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