Adrenal Medulla and Cortex
__ exhibit significant permissive actions for other hormonal activity
Glucocorticoids
__ need to be present for glucagon and catecholamines to exert their calorigenic effects
Glucocorticoids
Adrenal cortex secretes three things:
Glucocorticoids, mineralcorticoid, and sex hormones
Gluticocorticoid stimulates hepatic __
Gluconeogenesis
Glucocorticoids
Cortisol (primary) and corticosterone
Androgens
Hormones that exert masculinizing effects
Adrenal medulla secretes three catecholamines:
Epinephrine, norepinephrine, dopamine
Glucocorticoid effect on lipids
Facilitate lipolysis
Stress and diurnal rhythms stimulate __ to release __ hormone
Hypothalamus; corticotropin-releasing hormone (CRH)
Cortisol is metabolized by the
Liver
Renin is released in response to
Low sodium levels in the fluid
MAP = CO X TPR
Mean Arterial Pressure = Cardiac Output x Total Peripheral Resistance
Cells of the adrenal medulla secrete when they are stimulated by
Preganglionic nerve fibers
Small amounts of glucocorticoids are important for catecholamines to produce __ responses and broncho(dilation/constriction)
Pressor; bronchodilation
Cushing's Syndrome
Prolonged increase in plasma glucocorticoids
Cushing's Syndrome symptoms
Protein depletion, skin and subcutaneous tissues thin, poorly developed muscles, poor wound healing, easy bruising, body fat distribution, type 2 DM, mineralcorticoid effect (retention of sodium), hypertensive, osteoperosis, increased appetite, insomnia, mental symptoms
Stress causes (release/inhibition) of glucocorticoids
Release
Angiosensin II is dependent on the release of
Renin
Zona reticularis
Sex hormones
Adrenal cortex secretes __ hormones
Steroid
Glucocorticoid effect on proteins
Stimulate protein degredation
Epinephrine promotes breakdown of __ and __
Stored fat and carbohydrate
Glucocorticoids help a person resist
Stress
__ cortisol is what interacts with the tissue
Unbound (free)
Norepinephrine produces vaso(constriction/dilation) via alpha1 receptors
Vasoconstriction
Three layers of adrenal cortex
Zona glomerulosa (outer, 15%), Zona fasciculata (middle, 50%), Zona reticularis (lower, 7%)
The long term changes of adrenal androgens is due to changes in
17 alpha-hydroxylase (not ACTH)
75% of daily production of cortisol occurs between __ and __ (times)
4am and 10am
Half-life of cortisol is
60-90 minutes
Secretion of adrenal androgens is controlled by
ACTH (not gonadotropins)
ACTH acts on __ to release __
Adrenal cortex; glucocorticoids
Two endocrine organs in the adrenal gland:
Adrenal medulla, adrenal cortex
Zona glomerulosa
Aldosterone; new cortical cells
Androgens promote protein __ and __
Anabolism and growth
Aldosterone is regulated by __ levels and stimulated by high __ levels
Angiotensin II; plasma potassium
Aldosterone plays a role in potassium function by
Causing secretion of potassium into the urine when plasma potassium levels are high
Corticotropin-releasing hormone (CRH) stimulates __ to release __
Anterior pituitary gland; adrenocorticotropic hormone (corticotropin, ACTH)
Stress is defined as
Any change in environment that changes or threatens to change an existing optimal steady state
Glucocorticoids play an important role in
Carbohydrate, fat, protein metabolism
CO = HR X SV
Cardiac Output = Heart Rate x Stroke Volume
Pheochromocytoma
Catecholamine-secreting tumor
Five major hormones secreted by adrenal cortex
Cortisol, corticosterone, aldosterone, dehydroepiandrosterone (DHEAS), androstenedione
Zona fasciculata
Cortisol, glutococorticoids
__ have less than 20% of testosterone's activity
Dehydroepiandosterone sulfate (DHEAS)
Epinephrine (dilates/constricts) vessels in skeletal muscle and liver via beta2 receptors
Dilates
Result of epinephrine and norepinephrine together is that the total peripheral resistance (rises/drops)
Drops
Epinephrine and norepinephrine (increase/decrease) the force and rate of contraction of the heart by beta1 receptors
Increase
Glucocorticoids released from stress (increase/decrease) the pool of glucose, amino acids, and fatty acids
Increase
Aldosterone major function is to
Increase the resorption of sodium in the collecting ducts in the kidney.
Sympathetic stimulation (increases/decreases) renin release
Increases
Glucocorticoids (inhibit/stimulate) the hypothalamus and anterior pituitary gland
Inhibit
Glucocorticoids (inhibit/stimulate) the inflammatory response to tissue injury
Inhibit
Prolonged treatment of anti-inflammatory gluticocorticoids will (inhibit/stimulate) __ hormone release
Inhibit ACTH
Glucocorticoids will (inhibit/stimulate) glucose uptake by most tissues, except __
Inhibit; brain
Adrenal cortex (is/is not) essential to life
Is
Adrenal medulla (is/is not) essential to life
Is not (but helpful when dealing with emergencies and stress)
Rate of cortisol metabolism is decreased with
Kidney disease, stress
Secretion of adrenal androgens play __ roles in masculizing
Minimum
Two cell types that comprise the adrenal medulla
Norepinephrine secreting cells (10%), Epinephrine secreting cells (90%)
Secretion is initiated by the __ nervous system with __ release by the preganglionic neurons
Sympathetic; Acetylcholine
The most active androgen is __
Testosterone
Androstenedione is converted into __ and __ in fat and other peripheral tissues
Testosterone and estrogens
Gluticocorticoid-receptor complexes synthesize enzymes that alter cell function using this method
The complexes act as transcription factors that lead appropriate mRNAs to synthesize enzymes
Cortisol is bound to an alpha globulin called __
Transcortin (corticosteroid-binding globulin)