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NBDE PART 1 BIOCHEM/PHYSIOLOGY > Hormones > Flashcards

Flashcards in Hormones Deck (173):
1

somatotrophic hormone/somatotropin is aka

Growth hormone

2

GH is synthesized and secreted by cells called

somatotropes in anterior pituitary

3

GH stimulates body growth, secretion of _

IGF-1 and lipolysis

4

GH inhibits the action of

insulin on carb and lipid metabolism

5

major target of GH is

liver

6

GH causes liver to form small proteins called

somatomedins = increase bone growth

7

somatomedins are called

insulin like growth factors (IGFs) bc have similar effects as insulin

8

the most important somatomedin is

somatomedin C aka IGF-1.

9

IGF-1 concentration in plasma closely parallels

GH secretion

10

GH metabolic effects

increase rate of protein synthesis and breakdown of fatty acid from adipose = increase FFA in blood and increase use of FFA for energy

11

GH affect on glucose

decrease the rate of glucose utilization in the body

12

GH __ body protein, __ fat stores, __ carbs

GH increases body protein, depletes fat stores, and conserves carbs

13

GH _ blood glucose levels

raises, by decreasing peripheral tissue utilization = it is protein anabolic and lipolytic

14

Excess GH can lead to

gigantism and acromegaly

15

which one occurs after the growth plates have closed: gigantism and acromegaly

acromegaly

16

what stimulates GH secretion

decrease blood glucose/free fatty acids
starvation/fasting/protein deficiency
trauma/stress/excitement
exercise
testosterone estrogen
deep sleep stages 2 and 4
GHRH

17

what inhibits GH secretion

increased blood glucose/FFA
aging
obesity
GHIH (somatostatin)
GH exogenous
somatomedins (IGF)

18

Only _ cells express the androgen receptors and the FSH receptors

sertoli cells

19

all of the hormones use adenylyl cyclase-cAMP second messenger except one:
a ACTH
b calcitonin
c. glucagon
d. somatostatin
e. TRH

TRH

20

hormones that utilize second messengers are usually

water soluble peptide/protein hormones

21

the most important target of cAMP is

protein kinase A

22

cAMP is degraded by a group of enzymes known as

phosphodiesterases

23

cAMP is synthesized from

ATP by adenylate cyclase = a hormone controlled enzyme in plasma membrane

24

best stimuli to increase rate of TSH secretion by anterior pituitary:

exposure to heat
exposure to cold
exposure to stress

exposure to cold

25

TSH is aka

thyrotropin

26

TSH is secreted from

thyrotropes of the anterior pituitarty

27

TSH controls the rate of secretion of T4 (thyroxine) and T3 (triiodothyronine) of the thyroid and these hormones control the rates of most __ chemical reactions in the body

intracellular (inside the cell)

28

stress will __ TSH secretion

inhibit. bc inhibits secretion of TRH

29

Thyrotoxicosis

Thyrotoxicosis means an excess of thyroid hormone in the body. Having this condition also means that you have a low level of thyroid stimulating hormone, TSH, in your bloodstream, because the pituitary gland senses that you have “enough” thyroid hormone

30

long acting thyroid stimulator (LATS) is found in patients with

hyperthyroidism = stimulates thyroid

31

93% of the metabolically active hormones secreted by the thyroid glad is

thyroxine (T4)

32

however almost all of thyroxine is converted to

T3 in tissues so both are important functionally

33

which one is more potent T3 or T4

T3 is 4x as potent but is present in blood at much lower quantities and persists for a much shorter time than does thyroxine

34

hypothalamic hypophyseal portal system is bw the hypothalamus and the _ pituitary

anterior pituitary = blood vessels

35

the posterior pituitary hormones (ADH and Oxytocin) are synthesized in _

neuroendocrine cells located in the supraoptic and paraventricular nuclei of the hypothalamus

36

the synthesized hormones of the posterior pituitary are transported down AXON of a cell and stored in nerved terminal located in the

neurohypophysis (posterior pituitary)

37

ADH is formed in which nuclei of hypothalamus

supraoptic nuclei

38

oxytocin is formed in the _ nuclei of hypothalamus

paraventricular

39

ADH and oxytocin are packaged in granules that are transported down the axon of the cell and stored in _

nerve terminals located in the neurohypophysis (posterior pituitary)

40

when ADH is low, a __ amount of urine is excreted and it is dilute/concentrated

large amount dilute urine

41

ADH increase _ permeability in the

water
distal tubule and collecting ducts

42

oxytocin is secreted by the _ portion of the pituitary

posterior portion = paraventricular

43

oxytocin released in response to suckling and _ of the cervix

dilation

44

oxytocin stimulates the

smooth muscle of uterus and ontraction of myoepithelial cells surrounding the sac like alveoli of mammary glands

45

oxytocin release causes a _ feedback mechanism to begin

positive = uterine contractions push the fetus against the cervical opening which causes more oxytocin to be secreted. the rise in oxytocin causes greater uterine contractions and the cycle continues

46

increase in blood free fatty acid would __ insulin secretion (increase/decrease)

increase

47

insulin lowers blood glucose by binding _ receptors on _ muscles
this results in a cascade that translocates __ to the cell membrane

tyrosine kinase
striated muscle (cardiac and heart)
GLUT-4 glucose transporters

48

major stimuli for insulin is increased serum glucose and

some amino acids esp arginine ad lysine

49

insulin promotes utilization of _ for energy and depresses utilization of

carbs
fats

50

2 major actions of glucagon

glycogenolysis and glucogenesis both in the liver

51

insulin causes _ in the liver

glycogenesis (make glycogen)

52

sympathetic stimulation/parasympathetic would release glucagon

sympathetic

53

increased amino acid levels in the blood plasma would have what affect on insulin and glucagon

both would increase (this is when they do not act oppositely)

54

somatostatin (aka Growth hormone inhibitory hormone) acts locally in islets of Langerhans to _ secretion of Insulin AND glucagon

depress

55

as acid stomach contents pass into the small intestine the low pH triggers secretion of hormone: gastrin/secretin/cholecystokinin/gastric inhibitory peptide

secretin

56

secretin was the first Gi hormone discovered and is secreted by the _ cells in the mucosa of the duodenum in response to ACIDIC gastric juice emptying into duodenum

S cells

57

secretin acts like a firefighter and stimulates pancreas to release

bicarbonate base panc juice to neutralize the acid

58

Secretin inhibits/stimulates motility and gastric acids secretion

inhibits

59

secretin affect on gallbladder

release bile

60

secretin 3 functions

Stimulate pancreas to release panc juice high in bicarb, gallbladder to release bile, inhibits motility and acid secretion in stomach

61

cholecystokinin (CCK) secreted by _ cells in the mucosa of duodenum and jejunum

I cells

62

CCK released in response to _ entering intestine

fat, fatty acids, and monglycerides

63

CCK __ stomach contractions moderately

inhibits

64

Gastric inhibitory peptide GIP is secreted by mucosa of the upper small intestine in response to

fatty acids and amino acids, to lesser extent a.acids

65

GIP will inhibit

stomach motility

66

Gastrin is regulator of

gastric acid secretion

67

___has an impt trophic or growth promoting influence on gastric mucosa

gastrin

68

gastrin is secreted by _ cells in the _

G cells in the stomach

69

gastrin is released in response to stimuli associated with ingestion of a meal (distention of the stomach), products of protein degradation such as

gastrin releasing peptide which is released by nerves of gastric mucosa during vagal stimulation

70

primary action of gastrin

stimulate acid secretion and growth of gastric mucosa

71

the _ reflex forcefully closes the pyloric sphincter and reduces motility

enterogastric reflex

72

enterogastrones will

inhibit stomach secretion and motility = secretin, CCK, GIP

73

aldosterone is a __ corticoid

mineralcorticoid

74

aldosterone is secreted by cells in the

zona glomerulosa = adrenal cortex

75

major target of aldosterone

distal tubule of kidney

76

aldosterone effects

increase resorption of sodium and water and increased excretion of potassium

77

2 regulators of aldosterone secretion

extracellular potassium ion (K+) and Angiotensin II stimulates aldosterone

78

__ effects are opposite to aldosterone

atrial natriuretic peptide

79

Addison's disease is adrenocortical insufficiency. common symptoms are

hypotension, hyperpigmentation, muscle weakness, anorexia, hypoglycemia, hyperkalemic acidosis

80

why do we use synthetic estrogens and progestins in oral contraceptives instead of natural hormones

bc natural are destroyed by liver in a short time but synthetic are not

81

ovulation occurs as a result of __ induced LH surge

estrogen

82

unlike other steroid hormones, ALL ESTROGENS HAVE

an aromatic A ring

83

follicular cells of the thyroid gland synthesize thyroglobulin containing _

tyrosine

84

tyrosine residues of thyroglobulin are iodinated. iodinated tyrosine molecules bind to each other forming thyroglobulin bound T3 and T4. when the TSH is present, the T3 and T4 bound to thyroglobulin are transported back into the follicular cells and lysosomes release T3 and T4 from thyroglobulin into circulation. a dietary iodine deficiency will increase the secretion of

thyroglobulin

85

catecholamines are synthesized from what amino acid

tyrosine

caTecholamines = see the T

86

adrenaline is

epinephrine

87

noradrenalin is

norepinephrine

88

NE can be released by the adrenal medulla into the bloodstream. how

acetylcholine released from pre ganglionic sympathetic fibers innervating the adrenal medulla

89

NE can also be released directly onto an organ by

post ganglionic sympathetic adrenergic neuron that stored NE

90

the effect is more widespread when NE is released by adrenal medulla into blood or onto organ by postganglionic sympathetic neuron

adrenal medulla

91

Pheochromocytoma is a tumor of the

adrenal medulla = releases too much catecholamines (epinephrine and NE) = tachycardia hypertension anxiety sweating

92

adrenal medulla is a specialized ganglion of the _ nervous system

sympathetic

93

pre ganglionic fibers synapse directly on _ cells in adrenal medulla

chromaffin cells

94

chromaffin cells release 80% _ and 20% _into circulation

80% epinephrine
20% NE

95

are epinephrine and NE water or lipid soluble

water soluble therefore need a plasma membrane receptor to enter cell

96

Epinephrine/NE constricts blood vessels in almost all areas of body = increase TPR

NE

97

NE/Epinephrine dilates bronchioles

epinephrine

98

NE/Epinephrine activates muscle glycogen phosphorylase

Epinephrine

99

1. Chief cells in parathyroid gland release
2. chief cells in stomach release

1. PTH
2. HCl

100

hyperparathyroidism causes _ calcium and _ phosphate levels

high calcium
low phosphate

101

hypoparathyroidism (tetany)

decreased bone resorption decreased renal Ca2+ reabsorption , increased renal phosphate reabsorption and decrease production of active vitamin D

102

hyPOparathyroidism causes _ calcium and _ phosphate levels

decrease calcium
increased phosphate

103

the 5 C terminal amino acids of _ and _ are identical which explains their overlapping biological effects (GI HORMONES)

gastrin and CCK

104

Zollinger-Ellison syndrome is caused by excessive secretion of

gastrin = hypergastrinemia

105

three layers of the adrenal cortex

GFR: zona glomerulosa => zona fasciculata => zona reticularis

106

aldosterone is in which layer of adrenal cortex

zona glomerulosa

107

cortisol is in which layer of adrenal cortex

zona fasciculata

108

adrenal androgens are in which layer of adrenal cortex

zona reticularis

109

cortisol promotes __

gluconeogenesis, lipolysis, proteolysis, and immunosuppression

110

cortisol is a

glucocorticoid = influences lipid, carb, and protein catabolism.

111

glucocorticoids promote _ by inducing synthesis of the enzyme _

gluconeogenesis
PEPCK

112

the mineralcorticoid aldosterone and the glucocorticoids are collectively called

corticosteroids

113

mineralcorticoids have an aldehyde group at C#

C18

114

estrogens are distinguished by the

aromatic nature of ring A

115

corticosteroids are distinguished from the progestins by the presence of additional

OH groups

116

testosterone is a precursor for what two hormones

DHT and estradiol

117

testosterone promotes

protein synthesis

118

thyroxine promotes

glycogenolysis gluconeogenesis and lipolysis

119

cushing's syndrome results from

hypercortisolemia

120

adrenocortical insufficiency occurs from

patients who have been taking long term corticosteroids. this impairs the adrenal cortex from producing cortisol

121

progesterone, relaxin, estrogen, hCG and hPL are secreted by the

placenta = essential for pregnancy

122

is oxytocin secreted by the placenta

no

123

Somatostatin was first discovered in hypothalamic extracts and identified as a hormone that inhibited

secretion of GH

124

Subsequently somatostatin was found

in pancreas and GI tract and CNS outside of hypothalamus

125

Somatostatin acts by both endocrine and paracrine pathways to affect its target cells. the majority of circulating form comes from the

pancreas and GI

126

somatostatin inhibits

the secretion of many other hormones

127

which GI hormones does somatostatin inhibit

CCK, secretin, gastrin and vasoactive intestinal peptide

128

vasoactive intestinal peptide helps control

water secretion and absorption from the intestines. causes intestinal cells to secrete eater and salts into the intestine

129

the lacotropes of the anterior pituitary secrete

prolactin

130

primary action of prolactin is related to

breast development and function during pregnancy and lactation

131

the hypothalamus synthesizes PROLACTIN INHIBITORY FACTOR aka

dopamine

132

under normal conditions large amounts of dopamine are transmitted to the anterior pituitary gland so that the normal rate of prolactin secretion is slight. this is why they say prolactin is under

inhibitory control by hypothalamu

133

during pregnancy and lactation the formation of dopamine is suppressed which allows the anterior pituitary to secrete

prolactin

134

androgens are made in adrenal cortex and gonads and primarily affect

maturation and function of secondary sex organs (male sexual determination))

135

estrogens are made in adrenal cortex and gonads and primarily affect

maturation and function of secondary sex organs (female sexual determination))

136

progestins originate from

ovaries and placenta mediate menstrual cycle and maintain pregnancy

137

mineralcorticoids originate in

adrenal cortex and affect balance of salt and water

138

glucocorticoids made in the

adrenal cortex = decrease inflammation and increase resistance to stress

139

are steroid hormones stored in tissues

no.

140

steroid hormones act by _ receptors

intracellular

141

name the 3 hormones that control calcium

PTH, calcitonin, calcitriol

142

what is calcitriol? how many hydroxyl groups does it have

Calcitriol also called 1,25-dihydroxycholecalciferol or 1,25-dihydroxyvitamin D3, is the hormonally active form of vitamin D with three hydroxyl groups

143

calcitriol is formed in what part of the kidney

proximal tubule

144

calcitriol synthesis is stimulated by

hypocalcemia and hypophosphatemia

145

calcitonin is a peptide hormone secreted by

thyroid C cells aka parafollicular cells.

146

is calcitonin required in adults

no

147

the major regulator of calcium is

PTH

148

calcitonin inhibits

tubular reabsorption of calcium and phosphate

149

the amount of T4 produced and released by the thyroid gland Is controlled by:
pituitary or hypothalamus

pituitary

150

the thyroid gland is small, weighs less than an ounce and located in the _ of the neck

front

151

the thyroid has 2 halves called

lobes

152

the 2 lobes of the thyroid are connected by the

isthmus

153

the pituitary is the size of a

peanut

154

the function of the thyroid is to

take iodine from food and convert it to thyroid hormones

155

the ONLY cells in our bodies that can absorb iodine are

thyroid cells

156

thyroid cells combine the iodine with

tyrosine

157

thyroid hormones produce catabolic anabolic effects

catabolic

158

thyroid hormones are/are not lipophilic

are

159

ADH aka vasopressin is made in the _ nuclei of the hypothalamus and secreted in vesicles to the posterior pituitary. these vesicles are secreted with a carrier protein called

neurophysin

160

ADH stimulates water reabsorption by stimulating the insertion of _ into the membranes of the kidney tubules

water channels = aquaporins

161

the most important variable regulating antidiuretic hormone secretion is

plasma osmolarity (concentration of solutes in blood)

162

osmolarity is sensed by

hypothalamus osmoreceptors

163

nausea and vomiting would have what affect on ADH

stimulate release

164

ethanol and caffeine _ ADH release

decrease

165

nicotine __ ADH release

increase

166

sweating causes _ in ADH release

increase

167

drinking lots of water causes __ in ADH release

decrease

168

diabetes insipidus is caused by

hyposecretion of ADH

169

three classes of hormones are

proteins and polypeptides, steroids, derivatives of amino acid tyrosine

170

most hormones in the body are

polypeptides and proteins

171

all the anterior pituitary and posterior pituitary and pancreas and PTH are what kind of hormones

polypeptide and proteins

172

cortisol aldosterone estrogen and progesterone testosterone are what kind of proteins

steroid

173

thyroid hormones (T3 and T4) and adrenal medulla hormones epinephrine and NE are what kind of hormones

tyrosine produced