Adrenal glands Flashcards
What are adrenal glands
The wedges of grandular and neuroendorine tissue adhering to the top of the kidneys by a fibrous capsule
- rich blood supply - highest rates of blood flow in body
- served by arteries branching off aorta - suprarenal and renal arteries
What are the 4 tissue areas of the adrenal gland
Zona glomerulus: releases Meralcorticoids ex. Aldosterone
Zona Fasciculata: releases glucocoriticoids ex. Cortisol
Zona reticularis: releases Androgens ex. Dehydroepiandrosterone
Adrenal medulla: Stress hormones - NorEpi
The adrenal gland consists of what types of tissue
Outer cortex of glandular tissue
Inner medulla of nervous tissue
Outer cortex is divided into 3 zones
Zona glomerulus: releases Meralcorticoids ex. Aldosterone
Zona Fasciculata: releases glucocoriticoids ex. Cortisol
Zona reticularis: releases Androgens ex. Dehydroepiandrosterone
The adrenal cortex is a component of what?
and secretes steroid hormones that are important for what?
Hypthalamic-pituitary adrenal axis
important for
- long term stress response
- blood pressure
- nutrient uptake and storage
- fluid and electrolyte balance
- inflammation
The adrenal medulla is what?
Neuroendocrine tissue
composed of postganglionic sypatheric nervous system neurons
extension of autominc nervous system
regulates homeostasis of the body
When the medulla is stimulated it secretes what?
Epinepherine and Norepinephrine
One of the major functions of the adrenal gland is what
regulating stress
physical or psychological
What is stage one of the Gneral Adaptation Syndrome (body’s response to stress)
Alarm reaction - short term stress - fight or flight response
epinephrine or norepinephrine
prepares body for extreme physical exertion
What is the 2nd stage of GAS if 1st step doesn’t relieve stress
Stage of resistance
starvation mode- maximize absorbtion of nutrients
If stress continues past 2nd stage of stress what is the last stage of GAS
Stage of exhaustion
depression
supression of immune system
severe fatigue
mediated my hormones in adrenal cortex- cortisol
What is the most superficial region of the adrenal cortex and what group of hormones does it produce
Zona glomerulosa
Mineralocorticoids- hormones essential for fluid and electrolyte balance
What is a major Mineralocorticoid
Aldosterone
Important in regulation of the concetration of Na and K ions in urine sweat and saliva
key component in renin-angiotensin-aldosterone system
can increase blood pressue or blood volume
What are the 3 major functions of Angiotensin 2?
- Initiate vasoconstriction- decrease blood flow
- Stimulate kidney tubules to reabsorb NaCl - increase blood volume
- Signal adrenal cortex to secrete aldosterone - restore blood pressure and blood volume
An individual with hypertension or high blood pressure would want drugs that
Block production of angiotensin 2 ACE inhibitors
Intermediate region of adrenal cortex is what?
What hormones does it produce?
Zona Fasciculata
Glucocorticoids - gluclose metabolism
What is a major glucocorticoid?
Cortisol
long term stress for storage of nutrients
downregulation of immune system to inhibit inflammatory response - prednisone
What is the deepest region of the adrenal cortex?
What hormone does it produce?
Zona reticularis
Androgens
produces in response to ACTH from anterior petuitary and converted into testosterone or estrogen
Adrenal medulla releases hormones in response to what
Short term stress mediated by the SNS
What is the medullary tissue composed of
Unique pstganglionic SNS neurons called Chromaffin cells - large and irregular shapes
- produce neurotransmitters epinepherine and norepinephrine
Which is produced more Epinephrine or Norepinephrine
Epinephrine 4 to 1 ration
most powerful hormone
Epinephrine and Norepinephrine stimulate what?
Liver and skeletal muscle to convert glycogen into gluclose resulting in increased blood sugar levels
- increase heart rate, pulse, and blood pressure
What are the major hormones of the adrenal cortex
Aldosteron - increase blood pressure levels
Cortisol, coricosterone, cortisone - increase blood sugar levels
What is the major hormones of the adrenal medulla
Epinephrine & Norepinepherine - stimulate flight or fight response
