Lecture 7 - Pituitary physiology

Question 1

Pituitary effect loops: what is the standard loop and how do the latter stages affect the prior ones?

Answer 1

Hypothalamus - pituitary - effector gland

Produced effector hormone suppresses prior organs through a negative feedback loop

Question 2

How can we use pituitary/gland hormone levels to locate problems within the endocrine systems?

Answer 2

Compare pituitary and gland hormones to figure out what the issue is - ie high amounts of gland while pituitary is low (suppressed) then it is likely to be a gland issue

Question 3

Pituitary gland: what is it important for?

Answer 3

• Metabolic control
• Sexual function
• Fertility
• Puberty
• Water balance
• Stress response
• Growth
• Lactation
• Parturition (childbirth)

Question 4

Pituitary gland: what are the components of it?

Answer 4

• Anterior
• Posterior
• Pituitary stalk

Question 5

Optic chiasm: what is it and what clinical significance can it have with the pituitary gland?

Answer 5

Space just above the pituitary gland where the optic nerves cross over and where a pituitary tumour may invade, potentially causing a loss of vision

Question 6

Anterior pituitary axes: what are they?

Answer 6

• Growth
• Adrenal
• Gonads
• Thyroid
• Prolactin

Question 7

Posterior pituitary hormones

Answer 7

Vasopressin, oxytocin

(rewatch)

Question 8

Growth hormone system: what is the hypothalamic signal, what is the pituitary hormone, what is the target organ, and what is the downstream hormone?

Answer 8

Growth hormone releasing hormone (GHRH)

Growth hormone (GH)

Liver

Insulin-like growth factor-1 (IGF-1), resulting in growth

Question 9

Adrenal hormone system: what is the hypothalamic signal, what is the pituitary hormone, what is the target organ, and what is the downstream hormone?

Answer 9

Corticotropin releasing hormone (CRH)

Adrenocorticotropin hormone (ACTH)

Adrenal cortex

Cortisol

Question 10

Gonad hormone system: what is the hypothalamic signal, what is the pituitary hormone, what is the target organ, and what is the downstream hormone?

Answer 10

Gonadotrophin releasing hormone (GnRH)

LH/FSH

Gonads

Testosterone/oestrogen

Question 11

Thyroid hormone system: what is the hypothalamic signal, what is the pituitary hormone, what is the target organ, and what is the downstream hormone?

Answer 11

Thyrotropin releasing hormone (TRH)

Thyroid stimulating hormone (TSH)

Thyroid

T4 (T3)

Question 12

Prolactin hormone system: what is the hypothalamic signal, what is the pituitary hormone, and what is the target organ?

Answer 12

Dopamine, neuropeptides

Prolactin

Mammary gland

Question 13

Vasopressin: what is it, when is it released, and what does it do?

Answer 13

Anti-diuretic hormone (ADH)

Controlled by baroreceptors and osmoreceptors

Regulates water reabsorption in the kidney

Question 14

Oxytocin: what is it and what does it do?

Answer 14

Critical hormone in the processes of parturition and lactation and also social behaviours (notably bonding)

Question 15

Overactive thyroid: what are the key symptoms?

Answer 15

• High temps
• Quick metabolism
• Weight loss
• High bone turnover
• High heart rate

Question 16

Underactive thyroid: what are the key symptoms?

Answer 16

• Low temps
• Slow metabolism
• Weight gain
• Slow bone turnover
• Slow heart rate