adrenal medulla

medulla /me·dul·la/ (mĕ-dul´ah) pl. medul´lae   [L.] the innermost part; marrow.

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adrenal medulla , medulla of adrenal gland the inner, reddish brown, soft part of the adrenal gland; it synthesizes, stores, and releases catecholamines.

medulla of bone  bone marrow.

medulla oblonga´ta  that part of the brainstem continuous with the pons above and the spinal cord below.

medulla os´sium  bone marrow.

renal medulla  the inner part of the kidney substance, composed chiefly of collecting elements, Henle's loops, and vasa recta, organized grossly into pyramids.

spinal medulla , medulla spina´lis spinal cord.

medulla of thymus  the central portion of each lobule of the thymus; it contains many more reticular cells and far fewer lymphocytes than does the surrounding cortex.

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adrenal medulla

n.

Medulla of the adrenal gland.

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Adrenal medulla

The inner part of the adrenal gland. The adrenal medulla produces the hormones epinephrine (adrenaline), which stimulates the heart, tightens blood vessels, and relaxes some smooth muscles; and norepinephrine, which has similar effects.

Mentioned in: Adrenal Gland Scan, Pheochromocytoma, Vasodilators

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adrenal medulla,

the inner portion of the adrenal gland. Its cells secrete the catecholamines epinephrine and norepinephrine when stimulated by the sympathetic division of the autonomic nervous system. Compare adrenal cortex.

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adrenal

1. near the kidney.

2. of or produced by the adrenal glands.

3. an adrenal gland.

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adrenal cortex

the outer part of the adrenal gland made up of an external zona glomerulosa, a deeper zona fasciculata and a zona reticularis. It produces three main groups of hormones, the glucocorticoids which are concerned with increasing blood glucose levels, the mineralocorticoids concerned with the maintenance of electrolyte levels in the extracellular fluid, and androgens which have the same masculinizing effect as the hormone testosterone produced by the testis. Called also adrenal gland cortex. See glucocorticoid, mineralocorticoid, androgen.

adrenal cortex inhibitors

see adrenolytic.

adrenal-cortical

see adrenocortical.

adrenal cortical dysfunction

see hyperadrenocorticism, hypoadrenocorticism.

adrenal corticoids

see mineralocorticoid, glucocorticoid, corticosteroid.

adrenal function tests

see acth response test, dexamethasone suppression test, v-test.

adrenal hyperplasia-like syndrome

a congenital abnormality of adrenal steroidogenesis reported in dogs which results in hyperprogestinism and hyperandrogenism. Clinical signs include bilaterally symmetrical alopecia resembling that seen with other endocrinopathies.

adrenal insufficiency

hypofunction of the adrenal gland, particularly the cortex, leading to signs of weakness and loss of sodium, chloride and water. See also primary hypoadrenocorticism.

adrenal medulla

a glandular extension of the effector fibers of the sympathetic nervous system that releases into the bloodstream the hormones epinephrine (adrenaline) and norepinephrine (noradrenaline). When the sympathetic nervous system is stimulated the adrenal medulla responds also and its hormones are carried via the bloodstream to cause increases in cardiac output and metabolic rate, vasoconstriction and reduction of gastrointestinal peristalsis. The hormones have similar functions but epinephrine is removed from the bloodstream more slowly and has a more prolonged effect. Called also adrenal gland medulla.

Adrenal medullary hormones are not essential to life. Hypersecretion, such as occurs in some functional pheochromocytomas, causes tachycardia, edema and cardiac hypertrophy.

adrenal steroids

cortisol, corticosterone, cortisone, 11-dehydroxycortisone, desoxycorticosterone, 17-hydroxy-11-desoxycorticosterone, aldosterone, the adrenal corticoids from the adrenal cortex. Called also corticosteroids.

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medulla

pl. medullae [L.] the central or inner portion of an organ.

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adrenal medulla

the inner portion of the adrenal gland, where epinephrine is produced.

medulla of bone

bone marrow, contained in the medullary canal of bone.

medulla oblongata

that part of the hindbrain continuous with the pons anteriorly and the spinal cord posteriorly; it houses nerve centers for both motor and sensory nerves, where such functions as breathing and the beating of the heart are controlled. Called also myelencephalon. In animals the principal clinical manifestations of local lesions in the medulla are those of head rotation and circling, and facial and tongue paralysis with resulting difficulty in prehension and swallowing. With diffuse lesions spastic paralysis or a stiff-legged incoordination occurs.

medulla ossium

bone marrow.

renal medulla

the inner part of the substance of the kidney, composed chiefly of collecting tubules, and in some species organized into a group of structures called the renal pyramids.

spinal medulla, medulla spinalis

spinal cord.

medulla of thymus

the central portion of each lobule of the thymus; it contains many more reticular cells and far fewer lymphocytes than does the surrounding cortex.