Endocrine System

Question 1

Peptide hormones: polar or non polar?

Answer 1

Polar

Question 2

How do peptide hormones regulate organs?

Answer 2

Bind to extracellular receptors –> trigger transmission of a second messenger like cAMP, inositol triphosphate, and Ca

Question 3

Hormones that have a rapid onset and are short-lived: peptide or steroid hormones?

Answer 3

Peptide

Question 4

Hormones that have a slow onset and are long lasting: peptide or steroid hormones?

Answer 4

Steroid

Question 5

What are steroid hormones derived from?

Answer 5

Cholesterol

Question 6

How do steroid hormones regulate organs?

Answer 6

Bind to intracellular or intranuclear receptors –> creates hormone-receptor complexes –> conformational change –> bind to DNA –> affect transcription of a particular gene

Question 7

How do steroid hormones travel in the bloodstream?

Answer 7

With carriers

Question 8

Are steroid hormones active in the bloodstream?

Answer 8

No

Question 9

What can change the level of steroid hormones in the bloodstream? How?

Answer 9

Levels of carrier proteins –> the more carriers, the less active hormones!!

Question 10

What is the thyroxine bloodstream carrier? What hormones regulate its levels in bloodstream? What does this mean for pregnant women?

Answer 10

TBG
Estrogen and progesterone
Must secrete more thyroxine

Question 11

What are two examples of amino acid derivative hormones?

Answer 11

norepi and epi

Question 12

Difference between direct and tropic hormones?

Answer 12

Direct –> direct effects on non endocrine organs

Tropic –> direct effects on endocrine organs

Question 13

What is a paracrine signal?

Answer 13

Signal acts on cells in the local area

Question 14

What is an autocrine signal?

Answer 14

Signal acts on the same cell that secreted the signal

Question 15

What is a juxtacrine signal?

Answer 15

Signal acts on the adjacent cell (no diffusion)

Question 16

What is an endocrine signal?

Answer 16

Signal acts on a distant target tissue

Question 17

What are the five hormones released by the hypothalamus to the anterior pituitary? Roles?

Answer 17

GnRH: increase FSH and LH
GHRH: increase growth hormone
TRH: increase TSH
Corticotropin RH: increase ACTH
Prolactin inhibiting factor = dopamine: decrease prolactin

Question 18

What happens if there is a tumor in the anterior pituitary that stimulates the release of PIF?

Answer 18

Too much prolactin will be secreted by anterior pituitary

Question 19

What are the two hormones released by the hypothalamus to the posterior pituitary?

Answer 19

Oxytocin: stimulates uterine contractions and mammary glands contraction / smooth muscle in ductus deferens and prostate glands
Antidiuretic (ADH): increase reabsorption of water in collecting duct –> increase blood volume and decrease blood osmolarity

Question 20

Does oxytocin have a positive or negative feedback loop?

Answer 20

+

Question 21

What are the 7 hormones released by anterior pituitary? Tropic or direct? Role?

Answer 21

Tropic = FLAT:
FSH: acts on gonads
LH: acts on gonads
ACTH: acts on adrenal cortex
TSH: acts on thyroid

Direct: PEG
Prolactin: acts on mammary glands: stimulates milk production
Endorphins: decrease pain perception
Growth hormone: promotes bone and muscle growth and prevents glucose uptake by other tissues so that the blood glucose concentration increases + promotes fatty acid breakdown

Question 22

What are the 3 hormones released by the thyroid? Role?

Answer 22

T3/T4: increase metabolic rate
Calcitonin: decreases calcium blood concentration by:
- promoting Ca excretion in kidneys
- decreasing Ca absorption in gut
- promoting Ca storage in bone

Question 23

What can cause hypothyroidism? What are the symptoms ?

Answer 23

Cause: iodine deficiency or thyroid inflammation
Symptoms: lethargy, decrease in body temp, slowed respiration and heart rate, weight gain

Question 24

What can cause hyperthyroidism? What are the symptoms ?

Answer 24

Cause: tumor or overstimulation
Symptoms: increased activity level, increase body temp, increased respiration heart rate, weight loss

Question 25

What are the effects of hypothyroidism in children?

Answer 25

Cretinism and improper physiological development

Question 26

What types of cell release T3 and T4?

Answer 26

Follicular cells

Question 27

What types of cells release calcitonin?

Answer 27

parafollicular C-cells

Question 28

What is the 1 hormone released by the parathyroid? Role?

Answer 28

PTH: increases blood calcium concentration by: - decreasing Ca excretion in kidneys - increasing Ca absorption in gut - increasing bone resorption

Question 29

What is the effect of PTH on vitamin D? for what purpose?

Answer 29

It activates it --> necessary for Ca and phosphate absorption in gut

Question 30

Does PTH affect the blood phosphate concentration?

Answer 30

No

Question 31

What are the 3 classes of hormones released by the adrenal cortex?

Answer 31

1. Glucocorticoids 2. Mineral corticoids 3. Cortisol sex hormones

Question 32

What are the 2 glucocorticoids? Role?

Answer 32

Cortisol and cortisone: - increase blood glucose - decrease protein synthesis - inhibit immune system - -> stress response

Question 33

What is the mineral corticoid released by the adrenal cortex? Role?

Answer 33

Aldosterone: - increase water resorption by kidneys by increasing sodium resorption: increase blood volume, but no change in osmolarity

Question 34

What is aldosterone secretion regulated by?

Answer 34

Renin-angiotensin-aldosterone system: 1. decrease blood pressure 2. baroreceptors secrete renin 3. angiotensinogen is activated to angiotensin I 4. ACE converts it to angiotensin II 5. Stimulates adrenal cortex 6. Secretion of aldosterone 7. Negative feedback loop

Question 35

What are the cortisol sex hormones? Role?

Answer 35

androgens and estrogen: can masculinize females genitalia

Question 36

What are the two hormones secreted by adrenal medulla? Role?

Answer 36

Epi and norepi: sympathetic NS response

Question 37

What are the 2 stress response? Which is fast/slow?

Answer 37

1. Cortisol/cortisone: slow | 2. epi/norepi: fast

Question 38

What are the 4 hormones that raise blood glucose levels?

Answer 38

1. Glucagon 2. Growth hormone 3. Glucocorticoids 4. Epi/norepi

Question 39

What are the other 4 organs that release hormones? Role?

Answer 39

1. Stomach/intestine: secretin, gastrin (HCl secretion), cholecystokinin, ghrelin 2. Kidneys: eryothropoietin: stimulates bone marrow to produce erythrocytes 3. heart atria: ANP: promotes excretion of salt and water in response to high blood volume 4. Thymus: thymosin: stimulates T-cell development

Question 40

What hormones promote hunger?

Answer 40

Glucagon, ghrelin, and orexin

Question 41

What hormones promote satiety?

Answer 41

Leptin and cholecystokinin (CCK)

Question 42

What cells produce insulin?

Answer 42

Beta cells

Question 43

What cells produce glucagon?

Answer 43

alpha cells

Question 44

What cells produce somatostatin?

Answer 44

delta cells

Question 45

How do hormones bind to receptors?

Answer 45

Hormonal controls are covalent through phosphorylation and dephosphorylation → they modify covalent bonds

Question 46

List the 5 steroid hormones

Answer 46

glucorticoids, mineral corticoids, testosterone, estrogen, progesterone.

Question 47

List the 4 amino-acid derivative hormones. What aa do they come from?

Answer 47

T3, T4, epi, norepi (all from tyrosine)

Question 48

Are steroid hormones stored within the cell? Why?

Answer 48

No, because they are nonpolar and would freely exit the cell and diffuse out

Question 49

What hormones promote thirst?

Answer 49

ADH and aldosterone