Cortisol, Cushing's and Addison's stuff Flashcards
What are the 4 layers of the supra-renal gland?
1) . Zona glomerulosa
2) . Zona fasciculata
3) . Zona reticularis
4) . Adrenal medullla
Which layer takes up the majority of the adrenal gland?
Zona fasciculata
Describe the pathway of cortisol release
Hypothalamus produces CRH -> anterior pituitary produces ACTH -> zona fasciculata produces cortisol
How are cortisol levels inhibited?
Increased cortisol inhibits both the anterior pituitary and the hypothalamus in making CRH and ACTH
What does CRH stand for?
Corticotrophic Releasing Hormone
What does ACTH stand for?
Adrenal CorticoTrophic Hormone
What circulation system connects the anterior pituitary and the hypothalamus?
Hypophyseal portal system
What class of molecules is cortisol, and are they lipid or water-soluble?
Glucocorticoids = lipid-soluble
Describe the state of cortisol within the blood
Most cortisol is bound to a carrier protein called “Cortisol Binding Globulin”
Around 5% is free
- only a small portion of free cortisol is biologically active
What happens to excess free cortisol?
It is filtered by the kidneys and excreted in the urine
What are the 5 roles of cortisol?
1) . Part of our circadian rhythm
2) . Part of our response to stress
3) . Regulate blood pressure
4) . Dampen immune response
5) . Affect the brain (mood and memory)
How is cortisol involved in our circadian rhythm?
Alter our level of alertness:
- Levels rise in the morning
- Levels fall at night
What is the role of cortisol in our stress response?
1 - Increases gluconeogenesis
2 - Increases proteolysis
3 - Increases lipolysis
How does cortisol increase blood pressure?
Increases the sensitivity of peripheral blood vessel to catecholamines (like adrenaline), causes increased contraction
How does cortisol dampen the immune response
1 - Decreased release of inflammatory mediators like prostaglandins and interleukins
2 - Inhibiting T-lymphocytes
