Endocrine System

Question 1

endocrine system

Answer 1

gland of the body that produce hormones

Question 2

hormone

Answer 2

signaling molecule produced by body that elicit specific response

Question 3

endocrine

Answer 3

hormones that are transported through the body via blood to deliver their messages

Question 4

what are the roles of hormones?

Answer 4

-maintain homeostasis
-control digestion/metabolism
-responses to external stimuli
-sexual behaviors/cycles/differentiation

Question 5

negative feedback

Answer 5

the product that the hormone causes the target tissue to produce acts on the endocrine gland by telling it to stop producing the hormone

Question 6

positive feedback

Answer 6

the product that the hormone causes the target tissue to produce acts on the endocrine gland by telling it to produce more of the hormone

Question 7

negative feedback of insulin

Answer 7

when blood glucose levels are high, pancreas releases insulin. insulin tells cells to take glucose from the blood. blood glucose decrease, causing the pancreas to stop releasing insulin

Question 8

positive feedback example

Answer 8

fetus presses on the cervix, causing pituitary gland to release oxytocin. oxytocin causes uterus to contract, further pressing the fetus against the cervix. more oxytocin is released from the pituitary and the uterus contracts more. continues until birth of the baby.

Question 9

thyrotrophin-releasing hormone (TRH)

Answer 9

released by hypothalamus

causes release of thyroid stimulating hormone from thyroid

Question 10

gonadotrophin-releasing hormone

Answer 10

released by hypothalamus

causes release of LH and FSH from anterior pituitary

Question 11

corticotrophin-releasing hormone

Answer 11

released by hypothalamus

causes release of ACTH from anterior pituitary

Question 12

what hormones are produced by anterior pituitary?

Answer 12

growth hormone, TSH, FSH, LH, ACTH

Question 13

what hormones are produced by the posterior pituitary?

Answer 13

oxytocin and vasopressin

Question 14

what hormone is produced by the pineal gland?

Answer 14

melatonin

Question 15

what hormones are produced by the adrenal glands?

Answer 15

aldosterone, cortisol, epinephrine, and norepinephrine

Question 16

what 2 hormones are produced by the pancreas?

Answer 16

insulin and glucagon

Question 17

glucagon

Answer 17

released from pancreas when have low blood glucose. causes cells to release glucose, blood. glucose levels rise, and glucagon stops being produced

Question 18

what is insulin resistance in horses?

Answer 18

their cells are no longer sensitive to insulin, so cells do not take up glucose from the blood, causing blood glucose levels to increase. This triggers more insulin release. High levels of blood glucose and insulin.

Question 19

what are characteristics of insulin resistant horses?

Answer 19

keep on weight

irregular fat deposits

cresty neck

Question 20

equine metabolic syndrome

Answer 20

EMS; have excess body fat, sensitive to glucose, and more susceptible to laminitis; insulin resistance contributes to it

Question 21

how are insulin resistant horses managed?

Answer 21

low-starch diet, which reduces their need for insulin

Question 22

what hormone is involved in short-term stress response? Long term?

Answer 22

epinephrine; cortisol

Question 23

epinephrine effects

Answer 23

increases HR, expands airways, maximizes blood glucose levels via gluconeogenesis, more blood to muscles/brain

Question 24

HPA axis

Answer 24

Hypothalamus releases CRH

Anterior pituitary releases ACTH

Adrenal cortex releases cortisol

Cortisol negative feedback on anterior pituitary and hypothalamus

Question 25

cortisol effects

Answer 25

increases blood glucose by telling cells to ignore insulin; suppresses immune system

Question 26

equine cushing's

Answer 26

dysfunction of pituitary causing increased cortisol levels; usually caused by pituitary tumor; called pituitary pars intermedia dysfunction (PPID)

Question 27

how can PPID lead to insulin resistance?

Answer 27

more ACTH is being produced, so lots of cortisol is being produced by the adrenal cortex. cortisol tells the cells to ignore insulin and not pick up glucose from the blood. this can lead to the cells of the body becoming resistant to insulin over time

Question 28

thyroid hormones

Answer 28

T3 and T4; increase metabolic rate, HR, and breakdown of protein and fat

Question 29

thyroid axis

Answer 29

Hypothalamus releases TRH TRH causes release of TSH from anterior pituitary TSH causes release of T3 and T4 from thyroid gland

Question 30

hyperthyroidism

Answer 30

overactive thyroid, so excess T3 and T4 produced; causes goiter

Question 31

hypothyroidism

Answer 31

under active thyroid; not a lot of T3 and T4 produced; causes cresty neck

Question 32

what 2 conditions can cause slow metabolism and cresty neck?

Answer 32

EMS and hypothyroidism

Question 33

melatonin

Answer 33

wakes up mare's repro cycle; light reduces its production

Question 34

short-day breeders

Answer 34

melatonin stimulates reproductive cycles

Question 35

long-day breeders

Answer 35

melatonin suppresses reproductive cycle