Neuroendocrinology

Question 1

What’s the physiological role of the neuroendocrine system in homeostasis?

Answer 1

Stress, thyroid and gonad axes
Energy metabolism
Maintain blood pressure and blood osmolarity
Maintain body temperature

Question 2

What 3 processes of homeostasis does the hypothalamus control?

Answer 2

Behaviour (influences amygdala)
Neural control through ANS
Hormonal control via pituitary gland

Question 3

What are the 3 main hypothalamic nuclei and their functions?

Answer 3

Paraventricular nucleus (PVN - stress, energy balance, osmoregulation, maternal control, blood pressure

Supraoptic nucleus - osmoregulation and maternal control

Arcuate nucleus - reproduction, lactation and growth

Question 4

How does the hypothalamus regulate pituitary gland function?

Answer 4

Positive/negative feedback (neuroendocrine feedback)

Hormones secreted by neurosecretory cells into hypophysial portal system to the anterior pituitary from the parvocellular neurones

Magnocellular neurones directly secrete stimulating hormones onto posterior pituitary receptors

Question 5

Outline the 3 hypothalamic axes and their roles

Answer 5

HPA axis: CRH > ACTH > Coritsol (adrenal gland stress response)

HPT axis: Somatostatin/TRH > TSH > T3/T4 (thyroid metabolic response)

HPG axis: GnRH > LH/FSH > Oestrogen/Progesterone/Testosterone

Question 6

What hormone doesn’t have a releasing factor? But how is its release controlled?

Answer 6

Prolactin - stimulates body to produce breast milk

Short loop feedback system and DA secretion