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76 Cards in this Set
- Front
- Back
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What are the 3 zones of the outer adrenal glands?
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1. Glomerulosa
2. Fasciculata 3. Reticularis |
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What does each Adrenal zone produce?
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1. Glomerulosa - Mineral corticoids; ALDOSTERONE.
2. Fasciculata - glucocorticoids; CORTISOL. 3. Reticularis - Adrenal Androgens; SEX hormones. |
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What does the outer adrenal gland compose, what type of gland is it?
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cortex: 80-90% of the adrenals.
Gland that produces STEROIDS. |
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What is the inner adrenal gland?
How much of the adrenal gland? What does it produce? |
Adrenal Medulla; 10-20% of the whole gland.
Produces CATECHOLAMINES: Norepinephrine & Epinephrine. |
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What is special about the adrenal medulla?
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It is a modified sympathetic ganglion.
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What is the name of the cells in the adrenal medulla that synthesize and secrete hormone?
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Chromaffin cells - synthesize Norepi and Epi and package in vesicles.
(have high affinity for chromaffin stain) |
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What causes chromaffin cells to release their vesicle contents into the blood stream?
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Input from preganglionic sympathetic neurons; they release AcH which causes synapse.
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What are the ratios of epi and norepi output by the adrenal medulla?
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80-90% Epinephrine
10-20% Norepi |
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what are other names for epi and norepi?
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Adrenaline, noradrenaline
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What type of hormone are epi and norepi again?
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Catecholamines
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What is the major role of the hormones produced by the adrenal medulla (epi and norepi)?
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to protect the body against hypoglycemia.
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What stimulates and regulates epinephrine/norepi secretion?
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1. Low blood glucose
2. Exercise 3. Cold 4. Pain 5. Anger/stress |
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What is the function of the catecholamines?
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The FIGHT OR FLIGHT response
-increase blood glu -incr. cardiac output, FFA, blood flow to muscles. -Decreased GI activity. |
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Why do we have an adrenal medulla?
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To provide a response to acute and short term stress - by storing epi in vesicles, you don't have to wait for its synthesis.
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Why are epi and norepi especially valuable hormones?
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because they act on nervous system in places where nerves can't go, b/c they are transported by the bloodstream.
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How does Epi affect blood vessels?
What caues this? |
It dilates vessels in skeletal muscle;
-caused by B2 adrenergic receptor stimulation. |
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What has a better effect when released; epinephrine or nor?
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Epi - 10x better.
Because norepi does not act on Beta-2 adrenergic receptors. |
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What are the 2 effects of Epi and Norepi on the pancreas?
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1. Increased glucagon release
2. Decreased Insulin release |
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What are the 2 effects of Epi and Norepi on the liver?
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1. Increased Gluconeogenesis
2. Increased glycogenolysis -Breaks down glycogen to increase blood glucose. |
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What is the effect of Epi and Norepi on skeletal muscle?
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Increased glycogenolysis - breaks it down to use the glucose right in the muscle.
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What is the effect of Epi and Norepi on adipose tissue?
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Increased lipolysis to break down Triglycerides into glycerol and free fatty acids for gluconeogenesis.
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how specifically do Epi/norepi cause increased lipolysis?
Glycogenolysis? |
By increasing Hormone sensitive lipase.
Glycogen phosphorylase |
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What are two differences between hormones of the adrenal cortex and medullar?
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1. Cortical hormones are lipophilic - not H2O soluble.
2. Cortical hormones are not stored; only synth and released as needed. |
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What induces release of Cortisol and glucocorticoids?
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Stress - physical or emotional.
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What pattern governs how corticoids are released?
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Circadian rythms.
Increased release in AM Decreased at night. |
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How does ACTH affect the adrenal cortex?
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1.Simulates synthesis and release of cortisol
2. Upregulates steroidogenic enzymes 3.Increases cell size of synthesizing cells in the cortex. |
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What region of the cortex produces cortisol and glucocorticoids?
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the zona fasciculata
(glomerulosa acts on the renal glomerulus, mineralcorticoids) |
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what is the prohormone for ACTH?
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Pro-opiomelanocortin
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What happens to the adrenals if ACTH stimulation is decreased?
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They atrophy and become smaller.
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What is the whole pathway for cortisol release stimulation and inhibition?
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1. Hypothalamus produces CRH in response to stress.
2. Anterior pituitary produces ACTH 3. ACTH travels to pituitary and causes cortisol release. 4. Cortisol decreases insulin |
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How does ACTH cause cortisol synthesis/secretion, in contrast to how EPI/norepi are?
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It upregulates enzymes for gene expression; in general turns on Cortisol synthesis - takes TIME for the response.
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Why do we need to know that POMC is the prohormone for ACTH?
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Because the 1st 13 amino acids on its protein are alpha-MSH; high ACTH concentrations cause melanocyte stim, pigmentation.
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How does glucocorticoid synthesis/release fluctuate?
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Circadially - lowest at midnight, highest mid-morning.
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why is there a rythm to glucocorticoid release?
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To respond to stress fluctuations normal to every person.
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why are glucocorticoids vital for life?
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Without them you can't deal with stress, or prolonged fasting.
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What are the 3 main things glucocorticoids effect?
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1. Metabolism
2. Stress 3. Inflammation |
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How do glucocorticoids affect metabolism?
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Cortisol has an anti-insulin effect; result is to increase plasma glucose, amino acid, and calcium levels.
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How does cortisol affect bones?
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Increases break-down, can be a cause of osteoporosis.
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Why are glucocorticoids important for dealing w/ stress?
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-necessary for coping (idiopath)
-necessary for vascular smooth muscle to constrict -affects norepi/epi release by blood flow from cortex-medulla |
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What affect does cortisol have on immunity?
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suppresses immune response - an anti-inflammatory.
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Why are mineralcorticoids important?
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because they regulate Na/K levels, thus blood pressure, salt and water balance.
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What two things stimulate Aldosterone?
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-Decreased blood pressure/Na levels (detected by juxtamed apparatus)
-Increased sympathetic activity |
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By what pathway/system is aldosterone regulated?
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The renin-angiotensin system:
Angiotensinogen is activated by Renin; angiotens 1 activates to Angiotens II, and increases aldosterone. |
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what is the main stimlulator of aldosterone, and what is the affect?
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Angiotensin II, produced by the lungs; causes general vasoconstriction.
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What is the function of mineralcorticoids in a nutshell?
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Regulate Salt/Water balance by:
-Increasing Na reabsorption -Increasing K/H excretion |
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finish this!
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ok
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What 3 effects can Cortisol incur on the body at HIGH concentrations?
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1. Psychotic effects on mood
2. Osteoporosis (bone bkdown) 3. Immunosuppressant |
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What are the NORMAL effects Cortisol has on the body?
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Increased GLUCONEOGENEIS by
1. Skeletal muscle breakdown of glucose -> free amino acids 2. Liver glycogen breakdown -> free glucose 3. BLOCKING insulin to prevent glycogenesis. |
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What is the response to increased plasma glucose from cortisol's stimulation?
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it actually feedsback to incrase insulin levels in response to high blood glucose.
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How do blood glucose levels change as the body transfers from fed to fasting states?
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1. Blood glucose rises initially, in response to Cortisol.
2. Then gluconeogenesis stops when glycogen is exhausted; fatty acids + ketone bodies then take over. |
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OK keren, HOW DOES ALDOSTERONE CONTROL WATER AND SALT BALANCE?
(3 things) |
1. Stimulates Na+ reabsorption
2. Stimulates K+ excretion 3. Stimulates H+ excretion. |
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3 things that stimulate RENIN secretion:
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1. Decreased Na levels
2. Decreased blood pressure 3. Increased sympathetic NS activity |
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What happens when Renin is stimulated?
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The angiotensin system, which ultimately results in increased aldosterone synthesis.
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What are the 2 Adrenal Androgens?
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1. DHEA - dehydroepiandrosterone
2. Androstenedione |
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How does DHEA work, and what does the body do with it?
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1. Mimics testosterone and binds its receptors WEAKLY.
2. Body converts DHEA to testosterone in tissues. |
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What is the role of DHEA in
-Men? -Women? -Both? |
Men - has no role!
Women - probly causes hair growth, libido. Both - probly involved in development before puberty. |
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What is the one disorder that occurs in the adrenal medulla?
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Pheochromocytoma
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What in the world is Pheochromocytoma?
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A tumor of the chromaffin cells - therefore more Epi and Norepi are produced - makes you have high blood pressure.
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What are the 3 disorders of the Adrenal Cortex?
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1. Cushing's syndrome
2. Addison's disease 3. Congenital adrenal Hyperplasia. |
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What causes Cushing's syndrome?
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1. Therapeutic glucocorticoids causing high cortisol levels.
2. Hypothalamic, pituitary, or adrenal tumor -In general: HIGH CORTISOL |
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what is the result of high cortisol seen in Cushing's?
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-Moon face/buffalo hump
-fat re-distribution -Immune suppression -poor wound healing -muscle wasting -high blood glucose. |
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How does Addison's disease compare to Cushing's, pathologically?
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Cushing = cortisol overproductn
Addison = ADRENAL insufficiency - cortisol AND aldosterone. |
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What causes addison's disease?
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an autoimmune disorder where cortisol AND aldosterone are decreased; resulting ACTH increase causes pigmentation.
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What are the symptoms of addison's disease?
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-from low cortisol, inability to deal with stress, weak, fatigue.
-from low aldosterone, low blood volume, hypotensive - death. -from high ACTH, hyperpigment. |
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What is the underlying problem in congenital adrenal hyperplasia?
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An enzyme needed to synthesize the adrenal steroids is missing; The precursors of are shunted over to the ANDROGEN pathway.
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What is the result of congenital adrenal hyperplasia?
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-Cortisol/aldosterone are low
-Androgens (DHEA and androstenedione are high; -women/children are masculinized -men have low sperm counts -addison symptoms too |
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What is the one disorder that occurs in the adrenal medulla?
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Pheochromocytoma
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What in the world is Pheochromocytoma?
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A tumor of the chromaffin cells - therefore more Epi and Norepi are produced - makes you have high blood pressure.
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What are the 3 disorders of the Adrenal Cortex?
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1. Cushing's syndrome
2. Addison's disease 3. Congenital adrenal Hyperplasia. |
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What causes Cushing's syndrome?
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1. Therapeutic glucocorticoids causing high cortisol levels.
2. Hypothalamic, pituitary, or adrenal tumor -In general: HIGH CORTISOL |
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what is the result of high cortisol seen in Cushing's?
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-Moon face/buffalo hump
-fat re-distribution -Immune suppression -poor wound healing -muscle wasting -high blood glucose. |
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How does Addison's disease compare to Cushing's, pathologically?
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Cushing = cortisol overproductn
Addison = ADRENAL insufficiency - cortisol AND aldosterone. |
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What causes addison's disease?
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an autoimmune disorder where cortisol AND aldosterone are decreased; resulting ACTH increase causes pigmentation.
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What are the symptoms of addison's disease?
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-from low cortisol, inability to deal with stress, weak, fatigue.
-from low aldosterone, low blood volume, hypotensive - death. -from high ACTH, hyperpigment. |
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What is the underlying problem in congenital adrenal hyperplasia?
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An enzyme needed to synthesize the adrenal steroids is missing; The precursors of are shunted over to the ANDROGEN pathway.
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What is the result of congenital adrenal hyperplasia?
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-Cortisol/aldosterone are low
-Androgens (DHEA and androstenedione are high; -women/children are masculinized -men have low sperm counts -addison symptoms too |
