Lecture 20

Question 1

Hypothalamus function

Answer 1

Homeostasis, links the nervous and endocrine system via. the pituitary gland (hypophysis)

Question 2

2 parts of pituitary gland

Answer 2

Adenohypophysis (anterior, endocrine)
Neurohypophysis (posterior, nervous)

Question 3

Pituitary gland location

Answer 3

PG sits in the sella turcica (a depression of the sphenoid bone…)

Question 4

Three parts of anterior pituitary

Answer 4

Pars tuberalis (wraps around infundibulum)
Pars intermedia (between anterior and posterior pituitary)
Pars distalis (distal, main hormone-producing part)

Question 5

The optic chiasm is above the ___ and right in front of the ___

Answer 5

Pituitary gland, infundibulum

Question 6

Pars nervosa

Answer 6

Neural part of PG (posterior) that stores and releases hormones (doesn’t produce hormones)

Question 7

Posterior pituitary gland - hormones, nuclei from hypothalamus, pathway, and blood supply

Answer 7

Oxytocin - paraventricular nucleus
ADH - supraoptic nucleus
Hypothalamus produces hormones - hypothalamo-hypophyseal tract to neurohypophysis
Inferior hypophyseal artery

Question 8

ADH role

Answer 8

Released in response to decreased BP or blood volume, or rise in electrolytes, decreases amount of water lost at kidneys, and constricts blood vessels

Question 9

Oxytocin role

Answer 9

Stimulates milk production by mammary gland, uterine smooth muscle contraction, and contraction of myoepithelial cells of mammary gland

Question 10

Median eminence - location, what happens here, blood supply

Answer 10

At base of hypothalamus, neurosecretory cells of the hypothalamus secrete release/release-inhibiting hormones into the hypophyseal portal system that goes to the anterior pituitary to stimulate/inhibit hormone production and secretion
Superior hypophyseal artery

Question 11

Cortisol - pathway and function

Answer 11

Hypothalamus - CRH - PG - ACTH - adrenal glands - cortisol - negative feedback to hypothalamus/PG
Quickly increase available energy (glucose) in times of stress

Question 12

Hypothalamic inputs (5)

Answer 12

NTS (visceral information eg. BP and gut stretch), reticular formation, retina to suprachiasmatic nucleus, amygdala, intrinsic receptors (thermo- and osmoreceptors)

Question 13

Hypothalamus efferents (3)

Answer 13

Pituitary gland, ANS, limbic system

Question 14

Lateral vs ventromedial hypothalamic nuclei and lesion effect

Answer 14

Lateral - feeding center, lesion = no urge to eat or drink (aphagia and adipsia)
Ventromedial - satiety center, lesion = abnormally increased food intake

Question 15

Growth hormone and disorders

Answer 15

Cause increase in bone length and thickness (deposition of cartilage at ends of bones)
Too little GH - dwarfism
Excess GH prior to puberty - gigantism
Excess GH after puberty - acromegaly

Question 16

Pituitary tumors can cause ___ by pushing on the optic chiasm

Answer 16

Bitemporal hemianopsia (loss of both temporal visual fields)

Question 17

Pineal gland (epiphysis) function and signalling pathway

Answer 17

Produces melatonin (sleep hormone)
Some retinal axons - to SCN of hypothalamus via. retinohypothalamic tract - to pineal gland via. sympathetic nerves - inhibit melatonin production

Question 18

Anterior pituitary hormones (6) and function

Answer 18

FSH & LH (ovaries and testes) , GH (for bone and tissue growth), prolactin (milk production), ACTH (cortisol release), TSH (thyroid hormones)

Question 19

Role of SCN and melatonin

Answer 19

SCN is the ‘clock’ that regulates the brain the endocrine systems
Melatonin changes the speed of the ‘clock’ (jet lag hormone)