Endocrinology

Question 1

what are the 2 ways that the endocrine system function

Answer 1

nervous system
endocrine system

Question 2

what is a hormone

Answer 2

substance produced by a specific organ or gland that is transported to a distant site where it influences the activity of another organ or gland
(travels from the endocrine organ to the target organ via the blood stream)

Question 3

what are parahormones

Answer 3

not produced by true endocrine glands
doesn’t fit the classic hormone definition

Question 4

what are pheromones

Answer 4

chemical factor that will trigger a social response in members of the same species
ex: male knows that female is in estrous via pheromones

Question 5

why is knowledge of hormone chemistry important (2 factors)

Answer 5

1) cost
2) administration

Question 6

what are the 5 endocrine organs

Answer 6

pituitary
hypothalamus
gonads
uterus
placenta

Question 7

where is the pituitary gland located
where does it rest

Answer 7

located at the base of the brain
rests in a cavity of the sphenoid bone called the sella turcica

Question 8

what is pituitary gland composed of

Answer 8

2 lobes
anterior pituitary gland
posterior pituitary gland

Question 9

what is the purpose of the anterior pituitary gland

Answer 9

responsible for the synthesis, storage and release of 6 hormones

Question 10

what is somatotropin
what releases it

Answer 10

anterior pituitary gland
growth hormone
191 amino acid

Question 11

what is thyroid stimulating hormone
what releases it

Answer 11

anterior pituitary gland
stimulates thyroid gland which causes the realse of thyroxine
thyroxine controls metabolic rate

Question 12

what is adrenocorticotropic hormone
what releases it

Answer 12

anterior pituitary gland
stimulating effect on the adrenal cortex
this causes release of glucocorticoids- cortisol and used during parturition and corticosterone and used for metabolism of carbs (during times of stress)

Question 13

what is follicle stimulating hormone
what releases it

Answer 13

anterior pituitary gland
releases gonadotropin which stimulates male and female gonads
female- development of ovarian follicles which will result in the estrogen production
male- development of the seminiferous tubules which stimulates spermatogenesis

Question 14

what is luteinizing hormone
what releases it

Answer 14

anterior pituitary gland
releases gonadotropin which stimulates male and female gonads
female- final growth and ovulation of the follicle and maintains the corpus luteum
male- stimulates the leydig cells to produce testosterone

Question 15

what are the 2 non-pituitary gonadotropins

Answer 15

Equine Chorionic Gonadotropin (eCG)
Human Chorionic Gonadotropin (hCG)

Question 16

what is equine chorionic gonadotropin (eCG)

Answer 16

stimulates development of the fetal gonads in pregnant mares
mainly FSH like activity with slight LH activity
causes follicular development in mares, resulting in accessory corpus luteum
can cause superovulation in other species and synchronization

Question 17

what is human chorionic gonadotropin (hCG)

Answer 17

produces by the early placenta of pregnant women
mainly LH like activity with slight FSH activity
basis for early preg testing
can be used in farm animals to induce ovulation and increases production of testosterone

Question 18

what is prolactin
what releases it

Answer 18

anterior pituitary gland
favors lactation
function include: mammary development, maintain corpus luteum, maternal behavior

Question 19

what is the purpose of posterior pituitary

Answer 19

responsible for the storage and release of 2 hormones

Question 20

what are the 2 hormones that posterior pituitary gland

Answer 20

Antidiuretic Hormone
Oxytocin

Question 21

what is antidiuretic hormone
what realeses it

Answer 21

posterior pituitary gland
ADH regulates amount of water absorbed by kidneys
dehydration- ADH is released and water absorption is increased by the kidneys

Question 22

what is oxytocin
what releases it

Answer 22

posterior pituitary gland
smooth muscle stimulator: increase myometrium contraction for expulsion of fetus, aids in uterine sperm transport, aids in semen expulsion, aids in milk release

Question 23

what does the hypothalamus do and where is it located

Answer 23

regulates hormone release by the pituitary gland
located just above the pituitary gland

Question 24

what are the 3 segments of the hypothalamus

Answer 24

1- surge center
2- tonic center
3- paraventricular nucleus (PVN)

Question 25

hypothalamus what are the functions of the surge and tonic centers

Answer 25

responsible for the synthesis of hormones that regulate the release of anterior pituitary hormones regulation occurs via hypothalamic adenohypophysis portal system which is the capillary network that connects the hypothalamus and anterior pituitary

Question 26

What is the anterior pituitary aka

Answer 26

adenohypophysis

Question 27

what is the posterior pituitary aka

Answer 27

neurohypophysis

Question 28

what is the anterior pituitary hormone somatotropin (STH) and what is the hypothalamus releaser/inhibiter response

Answer 28

somatotropin releasing factor somatotropin inhibiting factor

Question 29

what is the anterior pituitary hormone (TSH) and what is the hypothalamus releaser/inhibitor response

Answer 29

thyroxine releasing factor (TRF)

Question 30

what is the anterior pituitary hormone Adrenocorticotropic hormone (ACTH) and what is the hypothalamus releaser/inhibitor response

Answer 30

Corticotropin Releasing Factor (CRF)

Question 31

what is the anterior pituitary hormone prolactin and what is the hypothalamus releaser/inhibitor response

Answer 31

prolactin releasing factor (PRF) prolactin inhibiting factor (PIF)

Question 32

what is the anterior pituitary hormone Follicle Stimulating Hormone (FSH) and Luteninzing Hormone (LH) and what is the hypothalamus releaser/inhibitor response

Answer 32

gonadotropin releasing hormone (GnRH)

Question 33

explain this

Answer 33

BMR- basal metabolic rate

Question 34

what are the functions of PVN (paraventricular nucleus of the hypothalamus)

Answer 34

responsible for synthesis and release of posterior pituitary hormone oxytocin and antidiuretic hormone

Question 35

in regard to PVN what are the functions of Oxytocin and Antidiuretic Hormone

Answer 35

1- travel down nerve fibers 2- stored at nerve endings 3- released into blood circulation

Question 36

what is the relationship between PVN and OC (endocrine hormone that regulates glucose metabolism) in regard to nerves

Answer 36

nerves are stimulated by 1-optic stimuli 2-audio stimuli 3-tactile stimuli 4-olfactory

Question 37

what are examples of optic stimuli

Answer 37

mother sees offspring male sees female in estrus

Question 38

what are examples of audio stimuli

Answer 38

mother hears offspring cow hears milk pump

Question 39

what are examples of tactile stimuli

Answer 39

physical contact between male and female in estrus intromission massaging the udder induced ovulatory

Question 40

what are the olfactory stimuli

Answer 40

male senses pheromones female smells intact male mother smells offspring

Question 41

what are the 3 hormones produced by the gonads and placenta

Answer 41

estrogen progesterone testosterone

Question 42

in regard to estrogen what are the hormones produced by the gonads and placenta where is the sources

Answer 42

granulosa cells of the ovarian follicles placenta, especially during later stages of pregnancy Sertoli cells of the testes cortex of adrenal gland

Question 43

in regard to estrogen what are the hormones produced by the gonads and placenta what is the functions

Answer 43

anabolic-stimulates the transfer of amino acids across cell membrane stimulates hyperplasia and hypertrophy in variety of tissues most growth promoting implants contain estrogen uterine growth, mammary gland development, stimulate proliferation and dilation of blood vessels, induces estrus, recruits smooth muscle oxytocin receptors

Question 44

in regard to progesterone what are the hormones produced by the gonads and placenta where is the sources

Answer 44

corpus luteum or luteal tissue placenta- primary source of progesterone during late pregnancy cortex of the adrenal gland leydig cells of the testes

Question 45

in regard to progesterone what are the hormones produced by the gonads and placenta what are the functions

Answer 45

keeps farm animal females out of estrous or heat termed the "governor" of the estrous cycle all other hormones involved in the estrous cycle are suppressed when levels of progesterone are high relaxing effect of uterine smooth muscle, stimulates uterine gland secretions, suppresses the GnRH release

Question 45

in regard to testosterone what are the hormones produced by the gonads and placenta where is the sources

Answer 45

leydig cells of the testes cortex of the adrenal gland theca cells of the follicle

Question 46

steroidogenesis the synthesis of all steroid hormones starts with _________

Answer 46

cholesterol

Question 46

in regard to testosterone what are the hormones produced by the gonads and placenta what are the functions

Answer 46

spermatogenesis, supports function of the tunica dartos and cremaster muscles, development of secondary sex characteristics in the male, anabolic- stimulates transfer of amino acids across cell membranes closure of epiphyseal lines in bones or calcification of bones, castrates will be larger frames

Question 47

what is prostaglandins where is it secreted

Answer 47

parahormones every organ in the body produces prostaglandins influence the glands that produce them

Question 48

what is the function of prostaglandins

Answer 48

smooth muscle stimulator receptor in vascular smooth muscle prostaglandins play a role in blood pressure regulation

Question 49

explain the luteolysis of a cow

Answer 49

Question 50

what is the mechanisms of luteolysis of a cow

Answer 50

PGF causes a reduction in blood flow to the CL PGF directly inhibits steroid production by the luteal cells