Ch. 5: The Endocrine System

Question 1

what are the organs of the endocrine system

Answer 1

glands

Question 2

what do glands secrete

Answer 2

hormones

Question 3

definition of hormones

Answer 3

signaling molecules that are secreted directly into the bloodstream to distant target tissues

Question 4

what are peptide hormones made of

Answer 4

long chains of amino acids, polypeptide sequences

Question 5

how are peptide hormones released from the cell

Answer 5

• packaged into vesicles
• released via exocytosis
• through plasma membrane d/t polarity/charge

Question 6

what is the first messenger in the signaling cascade

Answer 6

the peptide hormone that binds to an extracellular receptor and triggers the transmission of a second signal

Question 7

what is the second messenger in the signaling cascade

Answer 7

the signal that is released by the first messenger

Question 8

amplification

Answer 8

an increase in signal intensity d/t either one hormone binding to many receptors (first step) or one receptor activating multiple enzymes (second step)

Question 9

what is the timeline of the effect of a peptide hormone

Answer 9

rapid but short-lived d/t the transient nature of second messenger cascades

Question 10

how do peptide hormones travel in the bloodstream

Answer 10

freely because they are polar and therefore water soluble

Question 11

what are steroid hormones made of

Answer 11

cholesterol derivatives

Question 12

how are steroid hormones released from the cell

Answer 12

pass freely because they are nonpolar

Question 13

where are steroid hormone receptors located

Answer 13

intracellular or intranuclear

Question 14

where are peptide hormone receptors located

Answer 14

on the surface

Question 15

dimerization

Answer 15

pairing of two receptor-hormone complexes

Question 16

what effect do steroid hormones have on DNA

Answer 16

bind directly to DNA causing conformational changes and increasing or decreasing transcription of particular genes

Question 17

what is the timeline of the effect of a steroid hormone

Answer 17

effect is slower but longer-lived because of the effect on gene regulation

Question 18

how do steroid hormones travel in the bloodstream

Answer 18

they are carried by proteins because they are nonpolar

Question 19

how do steroids function while attached to proteins

Answer 19

proteins are inactive while attached to carrier proteins and must dissociate in order to function

Question 20

what are amino-acid derivative hormones made of

Answer 20

one or two amino acids with additional modifications

Question 21

what is the timeline of the effect of an amino-acid derivative hormone

Answer 21

highly unpredictable

epinephrine and norepinephrine are fast
thyroxine is long

Question 22

how do direct hormones act on target tissues

Answer 22

directly

Question 23

how do tropic hormones act on target tissues

Answer 23

via an intermediary

Question 24

what are the eight hormone glands

Answer 24

• hypothalamus
• pituitary
• thyroid
• parathyroid
• adrenal
• pancreases
• gonads
• pineal

Question 25

the hypothalamus bridges what two systems

Answer 25

endocrine and nervous systems

Question 26

how does the hypothalamus control the pituitary

Answer 26

through paracrine release of hormones into a portal system that connects them

Question 27

the hypothalamus is regulated by what type of feedback

Answer 27

negative feedback

Question 28

hypophyseal portal system

Answer 28

blood vessel connecting the hypothalamus and the anterior pituitary

Question 29

axes

Answer 29

three-organ systems involved in hormone feedback systems

Question 30

how does the hypothalamus control the posterior pituitary

Answer 30

hypothalamus axons extend directly into the posterior and release oxytocin and antidiuretic hormone

Question 31

what are the products of the anterior pituitary

Answer 31

FLAT (tropic) PEG (direct) ``` Follicle-stimulating hormone (FSH) Luteinizing hormone (LH) Adrenocorticotropic hormone (ACTH) Thyroid-stimulating hormone (TSH) Prolactin Endorphins Growth hormone (GH) ```

Question 32

what feedback systems regulates oxytocin release

Answer 32

a positive feedback system | contractions stimulate stronger contractions

Question 33

what does prolactin do

Answer 33

stimulates milk production in the mammary glands

Question 34

what do endorphins do

Answer 34

decrease perception of pain

Question 35

what do growth hormones do

Answer 35

promote growth of bone and muscle by - preventing glucose uptake in non-growing tissues - stimulating breakdown of fatty acids which allow growth to occur at epiphyseal plates

Question 36

what does antidiuretic hormone do

Answer 36

increases reabsorption of water in the kidneys by increasing the permeability of the collecting duct to water

Question 37

what does oxytocin do

Answer 37

stimulates uterine contractions in labor and milk letdown during lactation

Question 38

what does thyroid-stimulating hormone do

Answer 38

controls the two major functions of the thyroid - setting basal metabolic rate - promoting calcium homeostasis

Question 39

what do triiodothyronine and thyroxine do

Answer 39

adjust basal metabolic rate by making energy production more or less efficient

Question 40

what do thyroid follicular cells produces

Answer 40

T3, T4, and C-cells

Question 41

what do C-cells produce

Answer 41

calcitonin

Question 42

what does calcitonin do

Answer 42

tones down calcium levels in the blood - IGNORE decreases gut absorption of calcium - STORE increases calcium storage in the bone - WASTE increases kidney excretion of calcium

Question 43

what does parathyroid hormone do

Answer 43

- increases blood calcium levels (opposite of calcitonin) also. .. - promotes phosphorous homeostasis - activates vitamin D

Question 44

what does the adrenal cortex secrete

Answer 44

corticosteroids (SUGAR, SALT, SEX)

Question 45

what do glucocorticoids do

Answer 45

regulate glucose levels (SUGAR) - cortisol - cortisone

Question 46

what do mineralocorticoids do

Answer 46

maintain salt and water homeostasis (SALT) | - aldosterone

Question 47

what are cortical sex hormones

Answer 47

androgens and estrogens

Question 48

what does the adrenal medulla secrete

Answer 48

epinephrine and norepinephrine

Question 49

where are the islets of langerhans cells located

Answer 49

in small clusters throughout the pancreas

Question 50

what cell secretes glucagon and when

Answer 50

islet alpha cells when glucose is low

Question 51

what cell secretes insulin and when

Answer 51

islet beta cells when glucose is high

Question 52

what cell secretes somatostatin and when

Answer 52

islet delta cells when glucose and amino acid concentrations are high (inhibits glucagon and insulin)

Question 53

what secretes melatonin

Answer 53

the pineal gland