Term
Adrenal Gland location?
two parts?
embryological origin? |
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Definition
Lies superior to each kidney
Cortex - comes from Intermediate Mesoderm
Medulla - from Neural Crest Cells |
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Term
| process of developing adrenal gland |
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Definition
1. gland develops between root of dorsal mesentery of the primitive gut & developing urogenital ridges
2. mesodermal fetal cells surround developing medulla (7 months 70% is fetal cortex)
3. permanent cortex develop outside fetal cortex at age of 4 months |
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Term
| 3 arteries that supply adrenal gland |
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Definition
1. superior suprarenal a. fr inferior phrenic a.
2. middle suprarenal a. fr aorta
3. inf suprarenal a. fr renal a. |
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Term
Describe Adrenal subcapsular plexus that arise from 3 diff. arteries
venous drainage? |
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Definition
1. Arteries of capsule
2. arteries fr cortex that form capillaries in cortex
3. arteries of medulla that form capillaries in medulla.
so medulla has a dual blood supply
medullary veins join and form the adrenal vein |
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Term
| name 3 layers of adrenal cortex |
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Definition
1. Zona Glomerulosa
2. Zona Fasiculata
3. Zona Reticularis |
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Term
zona glomerulosa
what layer in adrenal cortex?
what 2 types of cells found here?
how are they arranged?
what hormone is secreted here?
under control of what hormone? |
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Definition
beneath capsule (most outer layer)
columnar & pyramidal cells
arranged as rounded / arched chords
mineralocorticoid (aldosterone)
under control of Angiotensin II (a lil ACTH also) |
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Term
zona fasciculata of adrenal cortex
where is layer located?
how are cells arranged?
what hormone secreted here?
secretion under control of what hormone? |
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Definition
middle layer of cortex
arranged in straight chords, 1 or 2 cells thick, perpendicular to surface
secrete glucocorticoids (cortisol)
under control of ACTH
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Term
zona reticularis of adrenal cortex
where is layer?
how are cells arranged?
what two things are present here also?
what hormone secreted?
secretion controlled by what hormone? |
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Definition
layer closest to medulla
cells arranged in an anastomosing network
lypofuscin granules & pyknotic nuclei present
secrete steroid sex hormones (dehyroepiandrosterone)
controlled by ACTH |
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Term
hormones of adrenal cortex
are they stored here?
how do they exit/enter cells?
what's collaboration? |
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Definition
hormones are not stored, only synth & released on demand
they're steroids thus can diffuse across membranes
enzymes of SER & Mitochondria work together in the production of steroid hormones |
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Term
3 functions of glucocorticoids
describe (-) feedback loop |
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Definition
1. Regulate metabolism (glucose homeostasis)
2. provides resistance to stress
3. depress immune response
glucocorticoid negatively feedsback on hypothalamus excreting CRH & on pituitary (ACTH) |
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Term
| hypophysectomy & [stress or adding ACTH] affects on adrenal cortex |
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Definition
(removal of pituitary gland) - cause cortical atrophy (loss of zona fasciculata & reticularis)
adding ACTH will cause cortical hypertrophy
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Term
Stress response on Adrenal Medulla
describe sympathetic pathway
what excretory cells are in the medulla?
what is special about these cells?
what do they excrete? |
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Definition
stress -> hypothalamus -> sympathetic preganglionic neuron -> sym. post. ganglionic neuron (chromaffin cells)
chromaffin cells - they are neurons that lost their axons / dendrites & excrete directly into blood vessels
excrete epinephrine & norepinephrine |
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Term
Adrenal Medulla
1. why do chromaffin cells appear brown?
2. describe the chromaffin cells (structure, what surrounds them, what connects to them)
3. where are the excretory products?
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Definition
1. oxidation of catacholamines by chromic cells
2. modified sympathetic postganglionic neurons
surrounded by capillaries
innervated by presympathetic neurons
3. membrane bound secretory granules storing epi / norepi |
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Term
the conversion of norepi to epi is done by what enzyme which is made in response to what hormone?
where does this happen? |
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Definition
| PNMT converts them. it's made in response to glucocorticoids. this is done in the cytosol (after norepi is transported there out of the granules) |
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