18.3 Pituitary gland

Question 1

sella turcica

Answer 1

depression in the shpenoid; where pituitary gland lies

Question 2

pituitary gland hangs inferior to the

Answer 2

hypothalamus

Question 3

infundibulum

Answer 3

structure that connects the pituitary gland to the hypothalamus

Question 4

pituitary gland is held in position by

Answer 4

sellar diaphragm

Question 5

All nine hormones secreted by the pituitary gland use _______ as a second messenger

Answer 5

cAMP

Question 6

anterior lobe of pituitary is AKA

Answer 6

adenohypophysis

Question 7

Regions of anterior lobe

Answer 7

1. pars distalis
2. pars tuberalis
3. pars intermedia

Question 8

pars distalis

Answer 8

largest and most anterior portion of pituitary gland

Question 9

pars tuberalis

Answer 9

wraps around adjacent portion of infundibulum

Question 10

pars intermedia

Answer 10

narrow band bordering posterior lobe

Question 11

fenestrated capillaries

Near what region?

Answer 11

unusually permeable capillaries (near median eminence)

Question 12

portal vessels

Answer 12

blood vessels that link two capillary networks (in this case, portal veins)

Question 13

releasing hormone (RH)

Answer 13

stimulates the secretion of one or more hormones at the anterior lobe

Question 14

inhibiting hormone (IH)

Answer 14

prevents synthesis and secretion of hormones from anterior lobe

Question 15

hormone secreted by pars intermedia

Answer 15

MSH

Question 16

TSH

AKA, stimulation, and effects

Answer 16

AKA: thyrotropin

• released in response to TRH (thyrotropin releasing hormone
• triggers release of thyroid hormones

Question 17

ACTH

AKA, stimulation, and effects

Answer 17

AKA: corticotropin

• released in response to CRH
• stimulates release of steroid hormones by adrenal cortex.. specifically targets cells that produce gluccocorticoids

Question 18

gonadotropins

hormones and stimulation

Answer 18

hormones that regulate activities of testes and ovaries…. FSH and LH
-production stimulated by GnRH

Question 19

hypogonadism

Answer 19

abnormally low level of gonadotropin production. People with this condition do not mature sexually, and cannot produce functional sperm or oocytes

Question 20

FSH

AKA and effects

Answer 20

AKA: follitropin

• stimulates follicle growth in females, and nurse cells (aid in sperm development) in males
• FSH + LH stimulates secretion of estrogen by ovarian cells in females
• release of inhibin from testes and ovaries

Question 21

most important estrogen

Answer 21

estradiol

Question 22

LH

AKA and effects

Answer 22

AKA: lutropin

• FEMALES: induces ovulation, promotes secretion of estrogens and progestins (prepare body for possible pregnancy)
• MALES: stimulates production of androgens by the interstitial cells of the testes

Question 23

most important androgen

Answer 23

testosterone

Question 24

PRL

AKA, stimulation/inhibition, and effects

Answer 24

AKA: mammotropin

• PRL stimulates PIH (dopamine) release and inhibits secretion of PRF (prolactin releasing factors)
• stimulates: mammary gland development, milk production during pregnancy
• in males: helps regulate androgen production and makes interstitial cells more sensitive to LH

Question 25

GH | AKA, stimulation/inhibition, and effects

Answer 25

AKA: somatotropin - regulated by GH-RH and GH-IH - stimulates cell growth and replication by accelerating protein synthesis - liver responds by releasing somatomedins (insulin-like growth factors IGF that stimulate tissue growth)

Question 26

MSH | AKA, stimulation/inhibition, and effects

Answer 26

AKA: melanotropin - dopamine inhibits release of MSH - secreted by pars intermedia - increases production of melanin by melanocytes - usually no MSH in bloodstream

Question 27

posterior lobe of pituitary gland is AKA:

Answer 27

neurohypophysis.. contains axons of hypothalamic neurons

Question 28

neurons of the supraoptic and paraventricular nuclei manufacture...

Answer 28

ADH and OXT respectively. | -hormones move along axons in infundibulum to capillaries in posterior lobe.. "axoplasmic transport"

Question 29

ADH | AKA, stimulation/inhibition, and effects

Answer 29

AKA: vasopressin (VP) - released in response to rise in solute concentration in blood, or a fall in blood volume or blood pressure.. detected by osmoreceptors in hypothalamus - decrease water loss at kidneys. - alcohol inhibits release

Question 30

How does ADH in high concentrations effect blood vessels

Answer 30

vasoconstriction: narrowing of peripheral blood vessels.. elevates blood pressure.

Question 31

OXT | stimulation/inhibition, and effects

Answer 31

- stimulates smooth muscle contractions in uterus, promoting labor and delivery. (most of this hormone is secreted by uterus and fetus) - after delivery, promotes ejection of milk by stimulating contraction of myoepithelial cells around alveoli. Neuroendocrine reflex: milk let-down reflex

Question 32

OXT during sex

Answer 32

levels peak at orgasm. -causes smooth muscle contractions that may be important to ejaculation; contractions of uterus may help transport sperm toward uterine tubes

Question 33

diabetes insipidus | cause, effects, treatment

Answer 33

posterior pituitary doesn't release adequate amounts of ADH. results in polyuria (excessive urine production). -treated with desmopressin

Question 34

glucocorticoids

Answer 34

cortisol and corticosterone