13.3 Hormonal Regulation Flashcards
Where are the adrenal glands located?
On top of the kidneys
What is the inner layer of the Adrenal glands?
The Adrenal Medulla
What is the outer layer of the Adrenal glands called?
The Adrenal Cortex
Which hormones does the Adrenal Medulla produce?
Epinephrine (adrenaline) and Norephrine
What do Epinephrine and Norephrine regulate?
The Short Term Stress response aka Fight or Flight
Why is the Adrenal Medulla known as a neuroendocrine structure?
Because in developing embryo’s, sympathetic neurons and the adrenal medulla are made of nervous system tissue
What initiates the Adrenal Medulla to start releasing hormones?
In response to a stressor. neurons of the sympathetic system carry a signal from the hypothalamus directly to the adrenal medulla
What do Epinephrine and Norephrine do?
Increase breathing rate, heart rate, blood pressure, blood flow to the heart and muscles, and the conversion from glycogen to glucose in the liver. Pupils dilate and blood flow to extremities decreases
Why is the release of Epinephrine and Norephrine so rapid?
Because it is under nervous system control
How long do the effects of Epinephrine and Norephrine stay in comparison with effects of the nervous system?
About 10 times longer
What do the hormones released by Adrenal cortex trigger?
The long term stress response
What hormones are released by the Adrenal Cortex?
Glucocorticoids and Mineralocorticoids
What do Glucocorticoids do?
Increase blood sugar
What do Mineralocorticoids do?
Increase blood pressure
What are Gonadocorticoids?
Female and Male sex hormones produced by the Adrenal Cortex that supplement the hormones produced by the gonads
What category does Cortisol fall under?
Glucocorticoids
What is Cortisol produced by?
The Adrenal Cortex
What is Cortisol?
A steroid hormone synthesized from cholesterol
What happens in the Hypothalamus when the brain detects danger?
The hypothalamus secretes a releasing hormone, the releasing hormone stimulates the anterior pituitary to secrete Adrenocorticotropic hormone (ACTH)
What does ACTH do?
Targets the adrenal cortex which releases the stress hormone cortisol
What is the main function of Cortisol?
To raise blood glucose levels
How does Cortisol raise blood glucose levels?
It promotes the breakdown of muscle protein into amino acids which are taken out of the blood by the liver where they are used to make glucose
What causes negative feedback in the long term stress response?
Increased cortisol levels in the blood cause negative feedback in the hypothalamus and the anterior pituitary which stops CTH production and stops the release of cortisol
What can be a side effect of Cortisol?
Chronic Stress, impaired thinking, damage to the heart, HBP, diabetes and susceptibility to infections
Why does increased Cortisol lead to susceptibility of infection?
One of the ways the body fights infection is by inflammation, cortisol is a natural anti-inflammatory
What is the main Mineralocorticoid?
Aldosterone
What does Aldosterone do in the kidneys?
It stimulates the distal tubules to increase absorption of sodium into the bloodstream which absorbs more water into the bloodstream which increases blood pressure
What disease could happen if the adrenal cortex is damaged?
Addison’s disease
What happens in Addison’s disease?
The body secretes inadequate amounts of mineralocorticoids and glucocorticoids
What happens as a result to Addison’s disease?
Low blood sugar, sodium and potassium imbalances, weight loss
What does Low Aldosterone result in?
Loss of sodium and water from the blood
How is Addison’s disease treated?
Injections of glucocorticoids and mineralocorticoids
