Endocrine system - Pituitary hormones & insulin III

Question 1

What are the hormones of Adrenal Gland?

Answer 1

• Mineralocorticoids (Mineral Balance)
  Aldosterone
• Glucocorticoids (Glucose Metabolism)
  Cortisol
• Androgens (Masculinisation)
  Dehydroepiandrosterone
• Catecholamines (Sympathetic activation)
  Adrenaline/Noradrenaline

Question 2

Aldosterone (mineralocorticoid)(Recollect BP regulation RAAS)

Answer 2

Secretion – Stimulated by increased plasma [K+]
and RAAS system; largely independent of Hypothalamus-pituitary axis (ACTH)

Question 3

Sodium secretion happens in the…

Answer 3

kidney

Question 4

sodium reabsorption ^^^^ =

Answer 4

Sodium reabsorption^

water reabsorption^

Potassium excretion in urine^

Question 5

Hypoaldosteronism =

Answer 5

Deficiency in the enzyme required for synthesis of aldosterone

e.g. Hyperkalaemia, Hyponatremia, Hypovolemia, Hypotension and others

Question 6

Primary hyperaldosteronism (Conn’s syndrome) =

Answer 6

Excess aldosterone level

e.g. Hypokalaemia, Hypernatremia, Hypervolemia, Hypertension and others

Question 7

Androgens

Answer 7

Dehydroepiandrosterone (DHEA) and its derivatives are steroid hormone that regulates the development and maintenance of MALE characteristics (masculinisation)

Question 8

Androgens secretion?

Answer 8

Regulated by the level of ACTH (but no feedback axis to ACTH/CRH)

Question 9

Hypoandrosteronism and symptoms/effects= Deficiency in the enzyme required for synthesis of DHEA

Answer 9

Loss of energy, erectile dysfunction, libido, loss of muscle and bone mass and others

Question 9

Hypoandrosteronism and symptoms/effects= Deficiency in the enzyme required for synthesis of DHEA

Answer 9

Loss of energy, erectile dysfunction, libido, loss of muscle and bone mass and others

Question 10

Predominately in women =

Answer 10

Excess DHEA level

Excess hair (pubic and auxiliary hair growth), masculinisation

Question 11

What is the cortisol?

Answer 11

It’s your body’s main stress hormone

[ Cortisol and its derivatives are steroid hormones that regulates the glucose metabolism ]

Question 12

Cortisol secretion;

Answer 12

Regulated by the level of ACTH/CRH(HPA axis)

Question 13

Gluconeogenesis^, protein breakdown^

Decrease- glucose iuptake/ protein synthesis

Lipolysis^

Decrease - Glucose uptake, lipogeneis

Answer 13

High Physiological levels: Anti-inflammatory/immunosuppressive effects

Permissive role for other endocrine hormones

Several Biological functions

Question 14

Where does glugonegenesis take place?

Answer 14

Liver

Question 15

Protein breakdown
Glucose uptake/ protein synthesis HAPPENS in the

Answer 15

muscle

Question 16

Glucose uptake, lipogeneis HAPPENS in the

Answer 16

adipose

Question 17

What is cushing’s syndrome?

Answer 17

ACTH-secreting pituitary tumour

excess glucocorticoids

Question 18

Symptoms of cushing’s syndrome?

Answer 18

• upper body obesity with thin arms and legs
• Buffalo hump
• Red, round face
• High blood pressure
• Vertigo
• Blurry vision
• acne
• Female balding
• water retention
• Menstrual irregularities
• thin skin and bruising
• purple striae
• poor wound healing
• Hirsutism
• severe depression
• cognitive difficulties
• emotional instability
  sleep disorders
  -fatigue

Question 19

Cortisol – Addison’s disease

Answer 19

Adrenal insufficiency

Question 20

Autoimmune disease or by HIV or TB

Answer 20

not producing sufficient, cortisol, aldosterone and androgens

Question 21

Symptoms of Addison’s disease

Answer 21

Hair Loss
Blurred vision
Abdominal pain
Decreased appetite
Darkening of the skin
Weight Loss
Hypoglycaemia
Postural Hypotension

Question 22

Because of Addison’s disease

Answer 22

ACTH production increased, as is MSH (share same POMC-precursor as ACTH)
→ increase melanin content in skin

Question 23

Posterior Pituitary Hormones

Answer 23

Paraventricular (PVN) and supraoptic (SON) nuclei, and the neurons carrying oxytocin and ADH (vasopressin) to the posterior pituitary, where they are stored/ released

Question 24

What stimulates antidiuretic hormone (ADH) / Arginine Vasopressin (AVP)

Answer 24

Stimulated by Hypovolemia, Hyperosmolality and Hypotension

Question 25

ADH/AVP function

Answer 25

1) Increase permeability and hence re-absorption of water.

2) Stimulate ACTH release

3) Blood vessels – vasoconstriction (at higher [ADH])

Question 26

DCT & CD:

Answer 26

distal convoluted tubules and collecting ducts

Question 27

What decreases because of ADH

Answer 27

diabetes insipidus (DI): polyuria and polydipsia
Pituitary DI:

Inadequate release of ADH
Nephrogenic DI:

Dysfunction of receptors in collecting ducts

Question 28

What increase because of ADH

Answer 28

Syndrome of inappropriate ADH secretion (SIADH)

CNS pathologies, malignancy, CNS drugs

Rétention of water in the body, highly concentrated urine

Hyponaterimia (dilution effect not sodium loss)

Question 29

Oxytocin - positive feedback?

Answer 29

Stimulate “milk let-down”, expression of breast milk
Uterine smooth muscle - contraction
Maternal behaviour / sexual behaviour

Question 30

Hormones of Pancreas;

Answer 30

Insulin

Question 31

Acid amino chains in insulin

Answer 31

Initially as proinsulin (human, 86aa)

mw ~ 5800
A-Chain: 21 aa
B-Chain: 30 aa
Disulphide Bridges: 3

Half-life of 5-9 minutes

Question 32

Insulin - enzymes;

Answer 32

Involves 3 enzymes:
proconvertase 1 (PC1)
proconvertase 2 (PC2)
carboxypeptidase H (CPH)

Question 33

What is the ratio of zinc and insulin crystalloid core?

Answer 33

2 Zn 2+ : 6 insulin crystalloid core
(in secretory granules)

Question 34

Insulin&raquo_space;> Function (anabolic hormone)

Answer 34

Chronic metabolic disorder characterised by hyperglycaemia

Insulin deficiency (Type 1)
Impaired b-cell function and/ or loss of insulin sensitivity (insulin resistance) (Type 2)