mechanisms of hormone action Flashcards
1
Q
hormones can be _________, _________, or ________ derivatives
A
peptide
steroids
amino acids
2
Q
examples of peptide hormones?
A
ADH
insulin
3
Q
peptide hormones are all derived from larger ___________ that are cleaved during postranslational modification
A
polypeptides
4
Q
T / F - peptide hormones are charged
A
true
5
Q
the peptide hormone is considered the, ____________ it binds to the receptor and triggers the transmission of a second signal known as __________
A
first messenger
second messenger
6
Q
examples of hormone amplification?
A
- one hormone molecule may bind to multiple receptors
- each receptor may activate multiple enzymes
7
Q
common second messengers?
A
- cAMP
- IP3
- calcium
8
Q
the effects of peptide hormones are usually (rapid / slow) and (long / short) lived
A
rapid
short lived
*due to second messenger cascades
9
Q
T / F - peptide hormones are genrally water insoluable
A
false, they are water soluable
10
Q
T / F - peptide hormones can travel through the blood stream
A
true
*do not require carriers
11
Q
steroid hormones are derived from _____________
A
cholesterol
12
Q
steroid hormones are primarily produced by the ___________ and __________
A
gonads
adrenal cortex
13
Q
T / F - because steroid hormones are derived from nonpolar molecules, they can easily cross the membrane
A
true
14
Q
upon binding to the receptor, the steroid hormone-receptor complex undergoes conformation changes, the receptor can then bind directly to ________ in either increasing / decreasing _____________ of particular genes
A
DNA
transcription
15
Q
______________ is a conformational chnage that pair two receptor hormone complexes
A
dimerization
16
Q
the effects of steroid hormones are usually (rapid / slow) and (long / short) lived
A
slow
long lived
17
Q
why are steroid hormone effects longer lasting?
A
they participate in gene regulation, causing alterations in the amount of mRNA and protein present in a cell
18
Q
T / F - steroid hormones are not water soluable
A
true
19
Q
how are steroid carried through the blood stream?
A
carrier proteins
20
Q
examples of steroid hormones carrier proteins?
A
sex hormone binding globulin
albumin
21
Q
examples of amino acid derivative hormones?
A
epinephrine
norepinephrine
triiodothyronine
thyroxine
22
Q
thyroid hormones are derived from __________
A
tyrosine
*addition of 7 iodine atoms
23
Q
____________ hormones are secreted and then act directly on the target tissue
A
direct
24
Q
example of a direct hormone?
A
insulin
25
__________ hormones require an intermediary to act on the tissue
tropic
26
example of tropic hormones?
GnRH stimulates FSH and LH
LH stimulates gonads for testosterone production
27
where do tropic hormones usually originate from?
brain
anterior pituitary gland
28
examples of endocrine glands?
pineal gland
adrenal gland
gonads
pancreas
parathyroid
thyroid
hypothalamus
29
what organs serve partial endocrine roles?
kidneys
heart
GI glands
thymus
30
____________ is the bridge between the nervous and endocrine systems
hypothalamus
31
by regulating the pituitary gland through __________ hormones, the hypothalamus is capable of having organism wide effects
tropic
32
where is the hypothalamus located?
forebrain
33
hypothalamus controls the pituitary gland through __________ release of hormones
paracrine
34
what is the purpose of the suprachiasmatic nucleus in the hypothalamus?
receive light input from the retinae and helps control sleep-wake cycles
35
what doesthe hypothalamus control?
retinae light input
sleep-wake cycles
increases in blood osmolarity
regulate appetite / satiety
36
______________ is a blood vessel system that directly connects the hypothalamus with the anterior pituitary gland
hypophyseal portal system
37
hypothalamus tropic hormone:
GnRH
anterior pituitary hormone response:
?
FSH
LH
38
hypothalamus tropic hormone:
GHRH
anterior pituitary hormone response:
?
GH
39
hypothalamus tropic hormone:
TRH
anterior pituitary hormone response:
?
TSH
40
hypothalamus tropic hormone:
CRF
anterior pituitary hormone response:
?
ACTH
41
what happens when PIF is released from the hypothalamus?
PIF = prolactin inhibiting factor
decrease in prolactin secretion
42
____________ inhibits the hypothalamus and anterior pituitary from releasing CRF and ACTH
cortisol
43
what types of hormones are released by the posterior pituitary gland?
oxytocin
ADH
44
_____________ stimulates uterine contractions during labor and milk letdown during lactation
oxytocin
45
___________ stimulates increased reabsorption of water in the colelcting ducts of the kidneys
ADH
46
what are the seven main hormones secreted by the anterior pituitary gland?
FLAT PEG
FSH
LH
ACTH
prolactin
endorphins
GH
47
___________ stimulates milk production in the mammary glands
prolactin
48
the release of ___________ from the hypothalamus decreases prolactin secretion
dopamine
49
what are the two reactions that must occur for milk ejection?
1. oxytocin is released from the posterior pituitary gland, resulting in smooth muscle contractions of the breast
2. hypothalamus stops releasing dopamine onto the antioer pituitary gland, which allows prolactin to be released
50
____________ decrease the perception of pain
enodorphins
51
____________ promotes the growth of bone and muscle
growth hormone
52
GH is stimulated by _____________ secreted by the hypothalamus
GHRH
53
excess of GH in children? deficit of GH in children?
excess = gigantism
deficit = dwarfism
54
when is ADH secreted?
low blood volume
increased blood osmolarity
*results in greater water retention = increased blood volume and higher blood pressure
55
____________ is secreted during childbirth and allows for coordinated contraction of uterine smooth muscle
oxytocin
56
the thyroid is controlled by TSH secreted from the ___________ pituitary gland
anterior
57
what are the two major functions of the thyroid?
1. setting basal metabolic rate
2. promoting calcium homeostasis
58
triiodothyronine (T3) and thyroxine (T4) are produced by the iodination of tyrosine in the _____________ cells of the thyroid
follicular cells
59
increased amounts of T3 and T4 will lead to (increased / decreased) cellular respiration
increased
60
a deficiency of iodine may result in ____________ in adults or ___________ in children
adults = hypothyroidism
children = cretinism
61
an excess of thyroid hormone may result in _______________
hyperthyroidism
62
sid effects of hypothyroidism? hyperthyroidism?
hypothyroidism:
lethargy
low body temp
slowed respiratory / heart rate
cold intolerance
weight gain
hyperthyroidism:
heighted activity level
high body temp
increased respiratory / heart rate
heat intolerance
weight loss
63
what two types of cells are distinct within the thyroid tissue?
1. follicular cells
2. parafollicular cells (c cells)
64
follicular cells produce ____________
c cells produce ___________
follicular = thyroid hormones
c cells = calcitonin
65
what is the purpose of calcitonin?
decrease plasma calcium levels
66
what are the three ways calcitonin decreases plasma calcium levels?
1. increasing calcium excretion from the kidneys
2. decreasing calcium absorption from the gut
3. increasing storage of calcium in the bone
67
what hormone is produced by the parathyroid?
PTH
68
PTH serves as an antagonist hormone to ____________
calcitonin
69
what is the purpose of PTH?
increase blood calcium levels
phosphorus homeostasis
activates vitamin D
70
how does PTH increase blood calcium levels?
1. decreases excretion of calcium by the kidneys
2. increases absorption of calcium in the gut
3. increases bone reabsorption (freeing up calcium)
71
PTH activtes _______ which is required for the absorption of calcium and phosphate in the gut
vitamin D
72
the adrenal coretx secretes _________
cortiocosteroids
73
three types of cortiocosteroids?
1. glucocorticoids
2. mineralocorticoids
3. cortical sex hormones
74
____________ are steroid hormones that regulate glucose levels and protein metabolism
glucocorticoids
75
how do glucocorticoids raise glucose levels?
increasing gluconeogenesis
decreasing protein synthesis
76
two most common types of glucocorticoids?
1. cortisol
2. cortisone
77
glucocorticoids release is under the control of ______________
ACTH
78
hypothalamus release:
?
anterior pituitary gland release:
?
adrenal gland release:
glucocorticoids
hypothalamus = CRF
anterior pituitary gland = ACTH
adrenal gland = glucocorticoids
79
_____________ are used in salt and water homeostasis
mineralocorticoids
80
what is the most common mineralocorticoid?
aldosterone
81
aldosterone affects ________ reabsorption in the disal convoluted tubule and collecting duct
sodium
82
aldosterone decreases reabsorption of ________ and __________ ions, promoting their excretion in the urine
potassium
hydrogen
83
aldosterone is primarily under the control of _____________
renin-angiotensin-aldosterone system
84
decreased blood pressure cause _____________ cells to release renin
juxtaglomerular
85
renin cleaves an inactive plasma protein, __________, it its active form, __________
angiotensinogen --> angiotensin I
86
_____________ converts angiotensin I to angiotensin II
angiotensin-converting enzyme
87
angiotensin II stimulates the adrenal cortex to secrete _____________
aldoesterone
88
most common cortical sex hormones?
androgens
estrogens
89
T / F - females are much more sensitive to disorders of cortical sex hormone production
true
*ovaries secrete smaller amounts of androgens
90
main functions of the coticosteroids produced by the adrenal cortex?
3 S's
1. Salt = mineralocorticoids
2. Sugar = glucocorticoids
3. Sex = cortical sex hormones
91
the adrenal (cortex / medulla) is a derivative of the nervous system
medulla
92
what hormones does the adrenal medulla secrete?
catecholamines (epinephrine and norepinephrine)
93
what effects does epinephrine have? norepinephrine?
epinephrine:
increase breakdown of glycogen to glucose
increased basal metabolic rate
both epinephrine / norepinephrine:
increase heart rate
brochi dilation
shunt blood flow to sympathetic systems
vasodilation of blood vessels
94
cortisol = (long / short) term stress response
catecholamines = (long / short) term stress response
cortisol = long term (slow)
catecholamines = short term (fast)
95
T / F - the pancreas has both endocrine and exocrine functions
true
96
explain exocrine tissues
they secrete directly into ducts
97
in the pancreas, endocrine clusters of hormone producing cells are grouped together into ______________
islets of langerhans
98
the islets of langerhans contains what three types of cells?
1. alpha
2. beta
3. delta
99
what do the alpha, beta, and delta cells of the islets produce?
alpha = glucagon
beta = insulin
delta = somatostatin
100
____________ is secreted during times of fasting
glucagon
101
when glucose levels are low, glucagon increases glucose production by triggering _________, _________, and ________
glycogenolysis
gluconeogenesis
protein / fat degradation
102
T / F - when blood glucose is high, glucagon release is inhibited
true
103
___________ is secreted when blood glucose levels are high
insulin
104
why is insulin secreted after eating?
blood glucose levels are high = eating
insulin induces muscle and liver cells to take up glucose and store it as glycogen
105
insulin stimulates (anabolic / catabolic) process
anabolic
*such as fat and protein synthesis
105
underproduction, insufficient secretion, or insensitivity to insulin results in _________________
diabetes
hyperglycemia
*high blood glucose
105
excess insulin causes __________
hypoglycemia
*low blood glucose
106
common symptoms of diabetes?
1. polyuria = frequent urination
2. polydipsia = increased thirst
107
explain type 1 diabetes
autoimmune destruction of pancreas beta cells
low / absent insulin production
regular injections of insulin
108
explain type 2 diabetes
partially inherited, partially due to environmental factors
receptor level resistance to the effects of insulin
109
____________ is an inhibitor of both insulin and glucagon secretion
somatostatin
110
high ________ and _______ concentrations stimulate somatostatin secretion
blood glucose
amino aids
111
the testes secrete _________ in response to stimulation by ____________
testosterone
gonadotropins (LH and FSH)
112
the ovaries secrete ________ and _________ in response to stimulation by ____________
estrogen and progesterone
gonadotropins (LH and FSH)
113
where is the pineal gland located?
deep inside the brain
114
what does the pineal gland secrete?
melatonin
115
in the GI tract, where can endocrine tissue be found?
stomach
intestine
116
types of hormones secretes by GI endocrine tissue?
secretin
gastrin
cholecystokinin
117
kidneys release ____________ which increases water permeability in the collecting duct, and sodium / water reabsorption in the distal convoluted tubule and collecting duct
ADH
118
kidneys produce ___________ which stimulates bone marrow to increase the production of erthrocytes
erythropoietin
119
the heart releases __________ to help regulate salt and water balance
atrial natruiretic peptide (ANP)
120
how is ANP secretion activated?
atria are stretched from excess blood volume
121
what is the outcome of ANP release?
lowers blood volume and pressure
122
the thymus releases _____________ which is important for proper t cell development and differentiation
thymosin
