Week 4- hypothalamus and pituitary gland

Question 1

Pituitary gland is the central feature of the endocrine gland.

Briefly describe function.

Answer 1

Produces hormones that are released into the blood stream.
Receives signals from the brain and hypothalamus and responds by sending pituitary hormones to target glands.
Target glands produce hormones that provide neg feedback

This feedback enables the pituitary to regulate the amount of hormone that is released into the blood stream by the target glands

Question 2

Describe the physiological and anatomic relationship between the hypothalamus, post/ ant pituitary.

Answer 2

Pituitary gland lies beneath hypothalamus
The pituitary gland comprises the adenohypophysis (anterior lobe) and neurohypophysis (posterior lobe)
The anterior and posterior pituitary are derived from different embryonic tissues and hence function as separate glands
Axons from hypothalamic nuclei extend to the posterior pituitary
Other axons from hypothalamic nuclei extend to the median eminence, where they release hormones into the hypophyseal portal circulation

Question 3

Hypothalamic control of anterior lobe.

2 types

Answer 3

releasing hormone: stimulates synthesis of one/ more hormones at ant lobe. Hormones from hypothalamic neuron and released at median eminence and comes down to ant pit. By blood

Inhibiting hormone: prevents synthesis/ secretion of hormones from the anterior lobe

Rate of secretion is controlled by negative feedback

Question 4

Name the hormones produced by anterior pit gland.

Cell types—> hormone they secrete.

Answer 4

Somatotropes: Growth Hormone
Corticotropes: ACTH- adrenocorticotropic hormone
Thyrotropes: TSH- thyroid stimulating hormone
Gonadotropes: FSH- follicle stimulating hormone, LH- luteinizing hormone
Lactotropes: PRL- Prolactin

Question 5

Physiological Action of: Adrenocoricotropic hormone

Answer 5

Stimulates production of glucocorticoids and androgens by adrenal cortex.

Question 6

Physiological Action of: TSH

Answer 6

Stimulates production of thyroid hormones T3/T4 by thyroid follicular cells: maintains size of follicular cells

Question 7

Physiological Action of: Growth hormone

Answer 7

stimulates post natal body growth: stimulates triglyceride lipolysis: inhibits insulin action on carbohydrate and lipid metabolism

Question 8

Physiological Action of: FSH

Answer 8

Stimulates development of ovarian follicles, regulates spermatogenesis in testes

Question 9

Physiological Action of: LH

Answer 9

causes ovulation and formation of corpus luteum in ovaries, stimulates production of estrogen/ progesterone
Stimulates testosterone production by testes

Question 10

Physiological Action of Prolactin

Answer 10

essential for milk production by lactating mammary glands