Endocrine System (Topic 7) Flashcards
(109 cards)
1
Q
hat do exocrine glands do? (2)
A
secrete substances into a duct onto an epithelial surface
2
Q
What are some examples of exocrine glands? (2)
A
- Sweat glands
- salivary glands
- tear ducts
- sebum
- stomach bile?
3
Q
What do endocrine glands do? (2)
A
secrete substances into the interstitial fluid, then into the blood stream
4
Q
What type of gland secretes hormones? (2)
A
endocrine gland
5
Q
What is a hormone? (2)
A
a chemical messenger produced by an endocrine cell and travels through the blood stream
6
Q
What are iodinated amino acids? (4)
A
modified amino acid
7
Q
What are biogenetic amines? (4)
A
derived from amino acids
8
Q
What is a peptide hormone? (4)
A
polymers of amino acids (most hormones)
9
Q
What is a steroid hormone? (4)
A
lipids
10
Q
What are the thyroid hormones? (5)
A
- Triiodothyronine (T3)
- Thyroxine (T4)
11
Q
What are characteristics of thyroid hormones? (5)
A
- Iodine stored in thyroid.
- Can be produced for several weeks even without iodine consumption.
12
Q
What do thyroid hormones do? (5)
A
Regulate metabolic rate, growth, and brain development.
13
Q
Are thyroid hormones polar or nonpolar? (5)
A
NONPOLAR
14
Q
Are thyroid hormones polar or nonpolar? (5)
A
NONPOLAR
15
Q
Characteristics of nonpolar messengers? (5)
A
have intracellular receptors and bind to affect gene expression
16
Q
Where are thyroid hormone receptors found? What does this mean? (5)
A
the nucleus
- they cross the membrane by diffusion
- they alter gene expression
17
Q
What are the precursors for biogenic amines? (6)
A
Starts as an amino acid, does not end up as an amino acid
18
Q
What are catecholamines? (5)
A
biogenic amines dervied from tyrosine
19
Q
What are the three catecholamines? (5)
A
- epinephrine
- norepinephrine
- dopamine
20
Q
Characteristics of epinephrine? (5)
A
- = adrenalin
- secreted by the adrenal medulla
- Controls metabolism
- Neurotransmitter
21
Q
Characteristics of norepinephrine? (5)
A
- secreted by the adrenal medulla
- Can be converted to epinephrine
22
Q
Characteristics of dopamine? (5)
A
- produced by hypothalamus,
- secreted in portal circulation to affect secretion of prolactin by pituitary gland.
23
Q
Characteristics of histamine? (5)
A
- derived from amino acid histidine
- involved in bronchoconstriction and vasodilation
24
Q
Characteristics of serotonin and melatonin? (5)
A
- derived from amino acid tryptophan
- Regulation of intestinal movement
- Role in mood, appetite, sleep, circadian rhythms
25
How are peptide and protein hormones made? (7)
transcription and translation
26
What category do most hormones fall in? (7)
peptide and protein hormones
27
How are protein hormones released from the endocrine cell? (8)
exocytosis
28
how do protein hormones affect the target cell? (8)
They're Polar; they will do what any water-soluble messenger will do
29
Characteristics of steroid hormones (9)
- cyclic lipids
- derived from cholesterol
- Nonpolar
30
Are steroid hormones polar or nonpolar? (9)
Nonpolar
31
Steroid Hormone Synthesis (10)
- (set of enzyme mediated reactions)
- starting point is cholesterol
- 1-2 G-Protein coupled receptor
- cAMP production by activated adenylyl cyclase
- cAMP activates (phosphorylates) a kinase
- cholesterol released from lipid droplet
- transported to mitochondria
- back and forth between smooth ER and mitochondria
- released from cell by diffusion b/c its a steroid (small and nonpolar)
32
Why do steroid hormones not travel in vesicles? (10)
vesicles are for polar, lipid-soluble
- steroid are non polar and water soluble
33
If steroid hormones sit free in the blood, what happens to them? (10)
they'll clump together
34
Where are steroid hormones made? (11)
the kidney/adrenal gland and sex organs
35
What are corticoids secreted by? (11)
adrenalcortex
36
What does aldosterone do? (11)
mineralocorticoid, affects ionic balance (at kidneys).
37
What does cortisol do? (11)
glucorticoid; affects glucose metabolism
- Body’s response to stress
- Regulation of the immune system
38
What steroid hormones are made in the sex organs? (12)
androgens and estrogens
39
True or False. Sex hormones are exclusive to each sex. (12)
False
40
Would testes or ovaries produce more aromatase? (12)
ovaries (does more conversion of androgen to estrogen)
41
What does the ability of a cell to respond to a hormone depend on? (13)
the presence of receptors on or in the target cell
42
How is number of receptors regulated for water-soluble hormones? (13)
Exocytosis (upregulation) and endocytosis (downregulation=
43
How is number of receptors regulated for lipid-soluble hormones? (13)
- Alter gene expression (take in more or less)
- alter protein degradation
44
What is permissiveness? (14)
one hormone is required for another hormone to have its full effect
45
What can hormones do to receptors of target cells of other hormones? (14)
up-regulate them, increasing the response
46
What is an example of a hormone up-regulating the receptor of another hormone? (14)
Epinephrine targets adipocytes (fat cells) causing cells to release more fatty acids. Thyroid hormone up-regulates epinephrine receptors.
47
What does "the thyroid is permissive to epinephrine" mean? (14)
the response is bigger when both hormones are present.
thyroid is required for epinephrine to have its full effect
48
What can all endocrine disorders be categorized into? (15)
- too little hormone -> HYPOsecretion
- too much hormone -> HYPERsecretion
- reduced responsiveness of target cells -> HYPOresponsiveness
- increases responsiveness to target cells -> HYPERresponsiveness
49
Why do symptoms vary in endocrine disorders? (15)
they vary depending on the hormone or endocrine gland that is affected
50
What is the hypothalamus composed of? (16)
nervous tissue
51
What is the hypothalamus linked to? (16)
the pituitary by the infundibulum
52
What does the hypothalamus bridge? (16)
bridges neural and endocrine systems
53
what are the two lobes f the pituitary gland? (16)
anterior and posterior
54
What are the two posterior pituitary hormones? (17)
oxytocin and vasopressin (antidiuretic hormone; ADH)
- both peptide hormones
55
is oxytocin positive is negative feedback? (17)
positive
56
Examples of oxytocin release? (17)
- baby suckling
- birth
57
How can you tell oxytocin is a peptide? (17)
because of all of the amino acids in the structure
(lots of amine groups and double bonded oxygens)
58
What does vasopressin do? (18)
increase blood pressure
59
What category does posterior pituitary hormones fall in? (18)
neurohormones
60
What is the control of the anterior pituitary composed of? (19)
glandular epithelium (aka endocrine)
61
What does the control of anterior pituitary do? (19)
amplify signals produced by a few neurons
62
What is a tropic hormone? (20)
hormone that leads to the release of another hormone
63
Which hormones in the anterior pituitary pathway tropic? (20)
GHRH, SS, TRH, DA, and CRH
64
What is the difference between permissive and tropic hormones? (20)
- permissive works together to increase the response
- tropic leads to the production of another
65
What are the functions of cortisol? (22)
- maintains blood pressure
- prevents blood glucose from dipping too low
- puts "brake" on immune system to keep from overreacting
66
What does permissive action on the response to epinephrine and norepinephrine by muscles and blood vessels help maintain? (22)
maintains blood pressure
67
What does maintains cellular concentrations of metabolic enzymes required to produce glucose between meals do? (22)
prevents blood glucose from dipping too low
68
What does decreases events associated with the inflammatory response such as capillary permeability and production of prostaglandins do? (22)
puts "brakes" on immune system to keep from overreacting
69
What is common in diseases marked by reduced cortisol? (22)
autoimmune disorders
70
What is cortisol important for? (22)
fetal development (lungs, brain, intestines)
71
What is stress? (23)
situation with real or potential threat to homeostasis
72
What is the response to trauma, infection, pain, sleep deprivation, fright, etc.? (23)
stress
73
What happens when stressed? (23)
increased release of cortisol and epinephrine
- effects on organic metabolism
- enhanced vascular reactivity
- unidentified protective effects against stress
- inhibition of inflammation and specific immune responses
- inhibition of nonessential functions
74
What is adrenal insufficiency and its symptoms? (24)
plasma levels of cortisol are chronically below normal
- weakness, lethargy, loss of appetite
- low blood pressure; low blood sugar
(life-threatening if not treated)
75
What are some causes of adrenal insufficiency? (24)
Primary adrenal insufficiency (called Addison’s Disease)
- infectious diseases (such as tuberculosis) destroy adrenal gland cells
- adrenal gland tumors
- autoimmune attack of adrenal gland
Secondary adrenal insufficiency (reduction in ACTH)
- may arise from pituitary disease
76
What is Cushing's Syndrome? Primary? Secondary? (25)
Excess cortisol in the blood
Primary
- cortisol-secreting tumor of the adrenal gland
Secondary
- usually due to an ACTH-secreting tumor of the pituitary
77
What are symptoms of Cushing's Syndrome? (25)
- Osteoporosis
- Muscles weakness
- High Blood Sugar
- Immunosuppression
- Redistribution of fat
- High blood pressure
[Usually not fatal]
78
What does prolactin target? (26)
the breasts and milk-secreting cells
79
Where is prolactin produced? (26)
the anterior pituitary
80
What type of feedback does TRH have? (27)
negative feedback
81
What is the thyroid composed of? (28)
follicles
- follicular epithelial cells
- lumen containing colloid (protein-rich material)
82
What do thyroid follicles produce? (28)
T4 and T3
83
Where are thyroid hormone receptors? (29)
in the nucleus
84
What do thyroid hormones do? (29)
activate gene transcription
85
What do thyroid hormones receptors have a higher affinity for? (29)
T3 and T4
86
What type of actions does thyrpid hormone do? (29)
Metabolic:
- Increase absorption of carbohydrates
- Increase release of fatty acids by adipocytes
- Main action: stimulate Na+/K+ pumps
Permissive:
- up-regulate adrenergic receptors, mostly in heart and neural system
Growth and development:
- Lack of T3 and T4 cause slow growth
- T3 and T4 necessary to develop dendrites, synapses and myelin
- Lack leads to profound intellectual deficiencies
87
What is hypothyroidism? (30)
Damage or loss of function of thyroid
Often autoimmune
88
What is another cause of hypothyroidism and what is the symptom called? (30)
- lack of iodine in the diet
- goiter
89
What are some treatments for hypothyroidism? (30)
- iodine treatments if the lack is the cause
- synthroid (synthetic thyroid pills)
90
What causes hyperthyroidism? (30)
- Hormone-secreting tumor
- Over growth/activity
(can be cause BY a goiter)
91
What are some treatments for hyperthyroidism? (30)
- take beta blockers
92
What is a mitogen? (31)
something that stimulates mitosis
93
How do mitogens directly effect growth? (31)
it affects mitosis and cell division
94
What leads to bone growth? (32)
osteoblasts and chondrocytes
95
What do osteoblasts do? (32)
convert cartilagenous tissue to bone
96
What do chondrocytes do? (32)
creates new cartilage
97
What are epiphyseal growth plates? (32)
actively proliferating cartilage
98
What is the role of IGF-1? (32)
Stimulates differentiation and cell division of chondrocytes.
99
When does cartilage growth slow down and epiphyseal plates fuse? (33)
after puberty
100
Why are extracellular levels of calcium tightly controlled? (34)
101
How is calcium acquired and maintained? (34)
Bone:
- Reserve: 99% of body calcium
- Osteoblasts bone-forming cells; secrete a matrix that gets mineralized with Ca2+
- Osteoclasts break down bone by secreting H+; releases Ca2+ from bone
Kidneys:
- Active reabsorption after urine is filtrated
Gastrointestinal tract:
- Absorption from food through active transport
(All three are under hormonal control)
102
Osteoblasts vs osteoclasts (34)
Osteoblasts:
- bone-forming cells; secrete a matrix that gets mineralized with Ca2+
Osteoclasts:
- break down bone by secreting H+; releases Ca2+ from bone
103
What is parathyroid hormone secreted by? (35)
secreted by four parathyroid glands that are embedded in the thyroid gland
104
Go over Parathyroid hormone pathway! (35)
yayyyy thyroidddd
105
absorption vs Reabsorption vs resorption (35)
- absorption = taking in
- reabsorption = in the kidney because its gets filtered out and taken in again at the kidney
- resorption = bones (bone is broken down to free up the calcium)
106
What does vitamin D do to calcium absorption? (37)
it increases it in the GI tract
107
Where do we get vitamin D? (37)
diet and sunlight
108
Where is calcitonin secreted? (36)
from the thyroid, parafollicular cells
109
What does calcitonin do? (36)
- Opposite effect of parathyroid hormone
- Decreases plasma calcium concentration by inhibiting osteoclasts.
- Secretion stimulated by high plasma calcium concentration.
- Role doesn’t seem to be significant in day-to-day Ca2+ regulation.
(May work only when Ca2+ levels are very high)
