Pituitary hormones & Insulin Flashcards
Structure of adrenal gland
Zona glomerulosa
- Contains plenty of enzymes that convert cholesterol to aldersterone
Zona fasciculata
enzymes that convert cholesterol to cortisol
Zona reticularis
Enzymes to convert cholesterol to dehydroepiandrostrone
Chromaffin cells
Sympathetic innovation to release noadreline and adranaline
Aldersterone funtion
- Sodium reabsorbtion increase
- Increase in the absorbtion of water
- Increase of potassium secreation in urine
Hypoaldersteronism
- Decrease in enzyme required to synthesise aldersterone
- Causes Hyperkalaemia, Hyponatremia and Hypovolemia
Hyperaldersteronism
- Excess aldersterone levels (Conn’s disease)
Androgens
- Steroid hormone that regulates the development and maintenance of MALE characteristics
- Regulated by the level of ACTH
Hypoandrosteronism
- Deficiency in the enzyme required for synthesis DHEA
- Could cause loss of energy and erectile disfuntion
Excess DHEA level
Excess hair (pubic and auxiliary hair growth) masculinisation
Cortisol
- Steroid hormone that regulates the glucose metabolism
- Secreation regulated by the level of ACTH
- In adipose take glucose and lipogenisis this increase liposis
- Muscle increase in breakdown of protiens decrease glucose uptake
- increase in glucogenesis in the liver
Tumour in pituitary
- Increases excess cortisol and ATCH 80% chance
Cushing’s syndrome (excess glucocorticoids)
- Obesity with thin arms and legs
- Buffalo hump
- High BP and blood sugar
- vertigo
- Blurry vision
- Pink streach marks at the back and stomach due to collogen breakdown
Adrenal insufficiency
Addison’s disease
- Not producing sufficient cortisol and aldersterone
- hair loss
- blur in vision abdomin pain
- darkening of skin
- Weight loss
- Postural hypotension
- ATCH production increase increase in melanin in skin
Posterior pituitary hormone
- Para ventricular and supratropic nuclei and the neurone carry oxitcin and ADH
- Stimulated by Hypovolemia, Hyperosmolality and Hypotension
-Stimulate ACTH release - Vasoconstriction (at higher [ADH])
Decreases level ADH
diabetes insipidus (DI): polyuria and polydipsia
Pituitary DI:
Inadequate release of ADH
Nephrogenic DI:
Dysfunction of receptors in collecting ducts
increase in ADH
- Syndrome of inappropriate ADH secretion (SIADH)
- CNS pathologies, malignancy, CNS drugs
- Retention of water in the body, highly concentrated urine
- Hyponaterimia (dilution effect not sodium loss)
Oxytocin
- Stimulate expression of breast milk (positive feedback axis)
- Maternal and sexual social bonding
- Causes utrine smooth muscle contration
- Admister during labour to contract and dialate utrine
secreated from prosterior pituitary gland
Pancreas and hormones
- Mostly exocrine glands responsible for digestion
- Ilests of langahan which contain alpha cells, beta cells, delta cells and
Alpha cells
Secrete glucagon which increases glucose production
Beta cells
Secreate Insulin which reduces production of glucose
Delta cells
Secreate stomatostain which is a a global inhibitor
Insulin
- Peptide hormone
- 51 amino acids ( A - 21aa and B - 30aa)
- Molecular weight 5800
- 3 disulfide bridges
- Half life 5-9 and free move in blood not bound to protiens
Proinsulin to insulin
- Splice proinsulin using proconvertase 1 & 2
- Futher 3 amino acids need to be spliced using carboxypeptidase
- 1 insulin formation also forms 1 c peptide
Storage of insulin in beta cells
- 6 insulin molecules bind with the central zinc core (hexomer)
liver
Insulin function
- Decrease blood glucose levels by stimulating glugose uptake into live
- Promotes glycogen synthesis when energy is needed it is given back
- Inhibit gluconeogenisis and breakdown of glycogen breakdown
Muscle
Insulin function
- Stimulates protien synethis takes glucose as a substrate
- Metabolised and build protien
- Reduced protien breakdown
Anabolic process
Adipose tissue
Insulin function
- Stimulates glucose uptake and lipogenesis storage
- Inhibit breakdown of lipid molecule
