endocrine system

Question 1

Peptide hormones

Answer 1

derived from large polypeptides, charged and can’t pass through plasma membrane, so bind extracellular receptor; hormone is first messenger and triggers second messenger transmission (cAMP, IP3, and DAG); activates a G protein coupled receptor; has rapid for short lived response, quick to turn on response

Question 2

steroid hormones

Answer 2

derived from cholesterol, can easily cross membrane-intracellular receptors; upon binding, steroid-receptor complex undergo conformational change that allows to bind to dna and change transcription; slower response but longer lived; not water-soluble, must be carried by proteins (albumin)

Question 3

amino acid derived hormones

Answer 3

derived from one or two amino acids; includes catecholamines such as E and NE

Question 4

direct hormones

Answer 4

secreted and act directly on target tissue

Question 5

tropic hormones

Answer 5

require an intermediary to act; ex. when a hormone stimulates production of another hormone which then acts on target tissue

Question 6

hypophyseal portal system

Answer 6

hypothalamus exerts control on anterior pituitary through paracrine release of hormones into portal system that connects the two

Question 7

hypothalamus-posterior pituitary interaction

Answer 7

neurons in hypothalamus sends axons directly to posterior pituitary, which can release oxytocin and vasopressin (antidiuretic hormone-ADH)

Question 8

prolactin

Answer 8

released by anterior pituitary, stimulates milk production; dopamine release from hypothalamus decreases its secretion

Question 9

endorphins

Answer 9

decrease perception of pain; direct hormone released from anterior pituitary

Question 10

growth hormone

Answer 10

direct hormone released from anterior pituitary; promotes growth of bone and muscle, which requires lots of glucose; prevents glucose uptake in certain tissues that are not growing to allow muscle and bone to use it; GH release stimulated by GHRH from hypothal.

Question 11

ADH/AVP

Answer 11

secreted from posterior pituitary in response to low blood volume or increased blood osmolarity; increases permeability of collecting duct to water, which leads to greater reabsorption or water from nephron; leads to increased blood pressure

Question 12

oxytocin

Answer 12

released during childbirth, allows for contraction of uterus; also stimulated by suckling since it promotes milk ejection; positive feedback loop:oxy release leads to greater contractions which leads to more oxy release

Question 13

TSH

Answer 13

released from pituitary in response to TRH from hypothal.; stimulates thyroid to release T3 and T4

Question 14

Thyroid hormones

Answer 14

triiodothyronine (T3) and thyroxine (T4); have 3 and 4 iodine atoms respectively; increased amounts lead to increased cellular respiration, stimulatate metabolic activity; negative feedback leads to decreased TRH and TSH

Question 15

hypothyroidism

Answer 15

insufficient amounts of thyroid hormones as result of iodine deficiency or inflamed thyroid gland; causes decreased body temp, slowed respiratory and heart rate, and weight gain

Question 16

hyperthyroidism

Answer 16

excess of thyroid hormone, may result from tumor or thyroid overstimulation; can cause heightened activity, increased body temp, increased respiratory and heart rate, weight loss

Question 17

calcitonin

Answer 17

acts to decrease plasma calcium; increases calcium excretion from kidneys, decreased calcium reabsorption from gut, increased storage of calcium in bone

Question 18

parathyroid hormone (PTH)

Answer 18

raises blood calcium levels by decreasing excretion through kidneys, increasing reabsorption from gut, and breaking down bone to free up Ca; activates Vitamin D-increased absorption from gut

Question 19

glucocorticoids

Answer 19

secreted from adrenal cortex; steroid hormones, such as cortisol; stress hormones that increased blood glucose; under control of CRF and ACTH

Question 20

aldosterone

Answer 20

secreted by adrenal cortex; increased sodium reabsorption in convoluted tubule and collecting duct, which increases water reabsorption; increases blood pressure, but does not change plasma osmolarity

Question 21

adrenal medulla

Answer 21

releases catecholamines, NE and E to activate sympathetic nervous system; increases glycogenolysis (breakdown of glycogen), increases heart rate, dilates bronchi, alters blood flow to supply skeletal muscle, heart, lungs, and brain needed for response to stressor; short-term fast stress response

Question 22

pancreas

Answer 22

has exocrine and endocrine functions; has islets of Langerhans- groups of hormone-producing cells- contain either alpha, beta, or delta cells, which each produce different hormone

Question 23

glucagon

Answer 23

secreted when fasting as result of low glucose in blood; stimulates degradation of protein and fat, conversion of glycogen to glucose in order to increase glucose levels

Question 24

insulin

Answer 24

secreted when blood glucose levels are high, after a meal; induces muscle and liver cells to take up glucose and store as glycogen, stimulates anabolic processes

Question 25

hypoglycemia

Answer 25

too much insulin will result in low blood glucose levels

Question 26

hyperglycermia

Answer 26

insufficient insulin or insensitivity to insulin results in high blood glucose and leads to diabetes mellitus; causes excessive glucose in kidney (because too much in blood for it to reabsorb), leading to increased excretion of water

Question 27

somatostatin

Answer 27

released by hypothalamus; inhibitor of insulin and glucagon secretion; stimulated by high blood glucose and amino acid concentrations; also inhibits growth hormone secretion

Question 28

melatonin

Answer 28

secreted by pineal gland; involved in maintaining circadian rhythms; responds to decreased light from retina

Question 29

erythropoietin

Answer 29

stimulates bone marrow to produce red blood cells in response to decreased oxygen levels

Question 30

atrial natriuretic peptide (ANP)

Answer 30

in response to excess blood volume, promotes excretion of sodium, which increases urine volume

Question 31

substance P

Answer 31

involved with perception of pain