Exam 6: Neuroendocrine/pituitary

Question 1

What is the main sensory information that gets sent to the hypothalamus?

Answer 1

Blood pressure and temperature

Question 2

What are the trhee parts of the anterior pituitary?

Answer 2

Pars tuberalis, pars distalis, pars intermedia

Question 3

What are the two parts of the posterior pituitary?

Answer 3

infundibular stalk, posterior lobe

Question 4

What do neurons of the posterior pituitary secrete?

Answer 4

vasopressin and oxytocin

Question 5

What cells of the posterior pituitary make vasopressin and oxytocin? where are they located?

Answer 5

magnocellular neurons; supraoptic and paraventricular nuclei

Question 6

where do magnocellular nuclei secrete their peptides (oxytocin and vasopressin)?

Answer 6

Directly into systemic circulation

Question 7

What are the functions of vasopressin?

Answer 7

Increase water resorption in kidney, anti-diuretic, vasoconstriction. All raise blood pressure

Question 8

What are the stimuli that increase the release of vasopressin?

Answer 8

increased blood osmolality, hypovolemia, hypotension

Question 9

What are the functions of oxytocin?

Answer 9

smooth muscle contraction in breast to release milk, smooth muscle contraction in uterus to deliver baby

Question 10

What are the stimuli that increase release of oxytocin?

Answer 10

suckling, uterine stimulation

Question 11

What are the three families of hormones that the anterior pituitary secretes?

Answer 11

Somatomammotropins, glycoproteins, opiomelanocortin peptides

Question 12

What are the hormones under “somatomammotropins” secreted by the anterior pituitary?

Answer 12

Growth hormone, prolactin

Question 13

What are the hormones under “glycoproteins” secreted by the anterior pituitary?

Answer 13

Thyroid stimulating hormone, follicle stimulating hormone, luteinizing hormone

Question 14

What are the stimuli and effects of growth hormone?

Answer 14

exercise, stress, sleep; tissue growth and increased cellular metabolism

Question 15

What are the stimuli and effects of prolactin?

Answer 15

suckling, stress; development of mammary tissue, lactation

Question 16

What are the stimuli and effects of TSH?

Answer 16

exposure to cold temps; increase thyroid hormone to increase cell metabolism which raises body temp

Question 17

What are the effects of FSH?

Answer 17

men: increased spermatogenesis, women: increased development of ovarian follicles

Question 18

What are the effects of LH?

Answer 18

Men: works w/ FSH to increase spermatogenesis, stimulates testosterone, women: initiates ovulation, stimulates progesterone

Question 19

What are the hormones of opiomelanocortin peptides secreted by the anterior pituitary

Answer 19

adrenocorticotropic hormone, Beta-endorphine

Question 20

What are the stimuli and effects of ACTH?

Answer 20

stress; secretion of cortisol from adrenaline

Question 21

What are the stimuli and effects of Beta-endorphine?

Answer 21

stress; analgesia

Question 22

What are the precursors of opiomelanocortin peptides (ACTH and Beta-endorphine

Answer 22

pro-opiomelanocortin (POMC)

Question 23

Which is a shorter peptide: ACTH or Beta-endorphine?

Answer 23

ACTH

Question 24

What test could be used clinically to assess anterior pituitary function?

Answer 24

Inducing stress by injecting a small amount of insulin to induce hypoglycemia, leads to increased ACTH, Cortisol, Beta-endorphine, growth hormone

Question 25

What controls the release of anterior pituitary hormones?

Answer 25

Hypothalamic releasing hormones

Question 26

Describe the release of hypothalamic releasing hormones

Answer 26

synthesized in parvocellular neurons, transported via axons to median eminence, released from nerve terminals into hypophyseal portal vein where it travels to the secondary capillary bed in ant. pit. lobe and stimulates specific cells for specific hormones

Question 27

What are the excitatory hypothalamic releasing hormones and their targets?

Answer 27

thyrotrophin releasing hormone (TSH), gonadotropin-releasing hormone (FSH, LH), corticotropin-releasing hormone (ACTH, Beta endorphine), growth hormone-releasing hormone (Growth hormone)

Question 28

What are the inhibitory hypothalamic releasing hormones and their targets?

Answer 28

somatostatin (GH), dopamine (Prolactin)

Question 29

What hormonal changes occur after pituitary stalk section?

Answer 29

Increased prolactin, decrease of all other pituitary hormones

Question 30

What is diabetes insipidus?

Answer 30

Increase in water excretion leading to electrolyte imbalances

Question 31

What is the etiology of DI?

Answer 31

head trauma severing the stalk of the pituitary leading to decreased vasopressin, autoimmune destruction of magnocellular neurons, idiopathic

Question 32

What are the symptoms of DI?

Answer 32

polyurea, polydipsia

Question 33

What is the treatment of DI?

Answer 33

desamino-vasopressin, increased retention of H2O in the kidney

Question 34

What is galactorrhea-amenorrhea?

Answer 34

inappropriate lactation; hyperprolactinemia with cessation of menstraution

Question 35

What is the etiology of galactorrhea-amenorrhea?

Answer 35

microadenoma in pituitary that released prolactin, leading to decreased FSH and LH

Question 36

what is the treatment of galactorrhea-amenorrhea?

Answer 36

surgery, drugs DA receptor agonists to block prolactin