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57 Cards in this Set
- Front
- Back
A dysfuntion affecting the gland out in the peripheral that is going to secrete hormone is what type of dysfunction?
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Primary dysfunction
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A dysfunction at the pituitary or hypothalamic level is what type of dysfunction?
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Secondary dysfunction
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The adrenocortical axis refers to control by what?
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Brain
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Mineralocorticoids and aldosterone are controlled by what?
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Peripheral substrate system
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In a primary endocrine disorder of the adrenal cortex, what will be lost?
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GCC and MCC
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In a secondary endocrine disorder, what will be lost?
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Only one pathway
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What is the RLS in the synthesis of GCC and MCC?
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Uptake and conversion of cholesterol to pregnenolone
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Where does the uptake and conversion of cholesterol to pregnenolone occur?
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Zona Fasiculata and Zona Reticularis
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In the zona reticulata and zona reticularis, what enzyme is used to convert pregnenolone to 17 hydroxy pregnenolone?
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17-alpha hydroxylase
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Are steroids stored?
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NO, there is direct synthesis and release from adrenal cortex--> "ON DEMAND PRODUCTION"
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What is the major GCC synthesized in humans?
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Cortisol
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Once cortisol is out in the plasma, what is cortisol bound to?
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CBG made by the liver
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What percentage of cortisol is bound to CBG? What percentage of cortisol is in the free, bioactive form?
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95% bound
5% free |
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What is the half-life of cortisol?
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90-110 minutes
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What type of reaction is the following reacton?
cortisol(free) + CBG <-->cortisol + CBG (bound) |
Equilibrium reaction-->maintains a fixed level of free cortisol
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What are the 3 important sites in cortisol?
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1.17 site
2.20 site 3.A ring |
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Cleavage at what 3 sites render's cortisol inactive?
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17 site, 20 site, A ring
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Cleavage at any of the 3 imp. sites on cortisol results in what inactive metabolites?
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17-ketogenic steroids and 17-ketosteroids
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What happens to the inactive metabolites of cortisol?
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They are lost in the urine
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How can the amount of cortisol being released into the plasma be measured?
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Measure urine
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Cleavage of cholesterol at 3 important sites is what type of reaction?
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Phase I reaction
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After the phase I reaction of cortisol which produces inactive meatbolites, what can happen next?
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Phase II conjugation reaction to make the metabolites of cortisol even more water-soluble
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In the HPA axis, what hormone cannot be measured in the periphery?
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CRH
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In the HPA axis, what hormone can be measured in the blood?
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ACTH
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What things coming in higher in the brain can override the negative feedback system of the HPA axis?
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1.psychogenic, emotional, traumatic
2.cytokines-->inflammation 3.diurnal rhythm |
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During sleep what is the overall major physiologic function of the GCC system?
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To provide glucose to the brain. (during sleep one is fasting)
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Is the uptake of glucose into the brain insulin dependent or independent?
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Insulin INdependent
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During what stage of sleep is the HPA axis activated?
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Late stage of sleep
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What are the 3 main physiological actions of GCCs?
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1.Metabolic (glucose availability for brain)
2.Anti-inflammatory 3.Immunosuppression |
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Where are GCC catabolic? Where are GCC anabolic?
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1.Catabolic: Periphery
2.Anabolic: Liver |
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Why is the hypersecretion of GCC devastating?
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B/c it does cause breakdown of tissue in the periphery.
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How does cortisol exert its anti-inflammatory actions?
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By long-term actions at the genome (through GCC receptor)
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What does the HPA-GCC axis do to the immune system?
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Inhibits immune system
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Do cells in the zona glomerulosa have 17-alpha hydroxylase?
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NO
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What do cells in the zona glomerulosa have?
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Dehydrogenase enzyme
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In the mineralocorticoid pathway, what is the precursor that gets shunted through the microsomal enzyme pathways? What is the precursor in the GCC pahtway?
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1.Mineralocorticoid: Pregnenolone
2.GCC: 17-hydroxy pregnenolone |
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In the mineralocorticoid pathway, are synthesis and release coupled?
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YES
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How does the transport of aldosterone differ from the transport of cortisol?
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Aldosterone is only weakly bound to a plasma protein.
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What percentage of aldosterone is bound? What percentage is active?
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5% of aldosterone is bound
95% of aldosterone is free |
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What is the half life of aldosterone compared to the half-life of cortisol?
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Aldosterone: 20-30 min
Cortisol: 90-110 min |
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Where are both cortisol and aldosterone degraded and secreted?
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Degraded in liver
Secreted in urine |
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What are the 3 functions of angiotensin II?
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1.Direct vasoconstriction
2.Increases total peripheral resistance 3.Increase BP |
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What protein acts directly to simulate aldosterone secretion also?
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Angiotensin II
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What are the 2 main effects of aldosterone on the kidney?
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1.Genomic effect
2.Membrane effect |
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What disease state involves adrenocortical insufficiency?
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Addison's Disease
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What are the 2 types of insufficiencies with Addison's Disease?
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1.Primary Insufficiency
2.Secondary Insufficiency |
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In Addison's disease, what are 2 things that MCC insufficiency results in?
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1.Sodium loss-->dehydration
2.K retention |
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In primary Addison's disease, excess ACTH production causes what?
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Hyperpigmentation of the skin.
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What is the difference between primary Addison's Disease and secondary Addison's Disease?
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1.Primary-->Hypersecretion of ACTH
2.Secondary-->Hyposecretion of ACTH |
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In congential adrenal hyperplasia, what enzyme is deficient?
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21-beta-hydroxylase
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What are the 2 effects of congenital adrenal hyperplasia?
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1.Adrenal hyperplasia
2.Virilization |
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The following are all symptoms of what disease?
-weakness, fatigue, wt. loss, inability to maintain blood glucose levels during fasting -hyponatremia, hyperkalemia, dehydration -hyperpigmentation of skin |
primary and secondary adrenocortical insufficiency
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The following are all symptoms of what disease?
-Adrenocortical hypertrophy -Virilization |
Congential Adrenal Hyperplasia
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The following are all symptoms of what disease?
-Muscle atrophy, thinning of skin, redsitribution of fat to face and trunk, poor wound healing |
Cushing's Syndrome
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The following are all symptoms of what disease?
-HTN, polyuria, polydipsia, muscle weakness and tetany |
Primary Aldosteronism or Conn's Syndrome
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Anti-inflammatory activity is high for what drugs?
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GCCs
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Salt retaining activity is high for what drugs?
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MCCs
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