Pituitary physiology Flashcards
What are the key pituitary hormones?
ACTH (Adrenocorticotropic hormone)
TSH (Thyroid stimulating hormone)
GH (Growth hormone)
PRL (Prolactin)
FSH (Follicle stimulating hormone)
LH (Leutenizing hormone)
MSH (Melanocyte stimulating hormone)
ADH (Antidiuretic hormone)
Oxytocin
What axis is ACTH involved in?
HPA axis
What causes the release of CRH?
Stress and circadian rhythm
What stimulates ACTH production?
CRH (Corticotrophin releasing hormone) produced by the hypothalamus
What does ACTH stimulate?
The release of cortisol by the adrenal glands
What is the function of cortisol?
Glucose regulation
Increasing body fat
Defence against infection
Stress response
How does cortisol affect hormone production?
It decreases ACTH and CRH production
What axis is TSH a part of?
HPT axis
What stimulates TSH release?
TRH (Thyroid releasing hormone) produced by the hypothalamus
What does TSH stimulate?
T3 and T4 release
What does GH stimulate?
The liver to release somatomedins (E.g. IGF-1)
What stimulates prolactin release?
Drop in dopamine levels
Unlike many of the other axes, this is inhibited by the hypothalamus
The hypothalamus releases dopamine, which inhibits prolactin hormone; a decrease in dopamine levels causes an increase in prolactin levels
What is the function of prolactin?
Lactogenesis in the mammary glands
Breast tissue development
What are some structures affected by testosterone?
Muscle, bone, libido, the penis and hair follicles
What are some structures affected by oestrogen and progesterone?
Bone, fat, the vagina, heart and liver
