Endocrine System Flashcards
1
Q
endocrine gland
A
ductless gland that secretes its product (hormone) directly into the blood
2
Q
hormone
A
chemical substance synthesized and secreted by an endocrine gland into the blood and transported to a target organ where it causes effects
3
Q
latencies
A
time from release of hormone until effects start to be seen
4
Q
basics about how hormone works with target organ
A
hormone released from endocrine gland directly into blood stream. it travels in blood stream until it reaches TARGET ORGAN
5
Q
basics about how hormone works with receptor
A
at target organ, hormone attaches to a specific RECEPTOR on target organ
6
Q
basics about how hormone works with HRC
A
the resultant hormone-receptor complex (HRC) causes a change to be made in the target organ
7
Q
characteristics of steroids
A
- structure similar to cholesterol
- derived from cholesterol or Vitamin D
- fat soluble (lipophilic or hydrophobic)
- –transported in blood via carriers proteins
- –diffuses through target cell membrane
- –attaches to intracellular receptor
- usually not stored, created as needed
- –longer latency periods
8
Q
examples of steroids
A
cortisol
aldosterone
estrogen
testosterone
9
Q
characteristics of non-steriods
A
- water soluble (hydrophilic or lipophobic)
- –travels dissolved in plasma
- –cant diffuse through cell membrane
- –attaches to receptors on outer surface of cell membrane of target cels (except T3/T4)
- large amounts stored in vesicles until needed
- –much shorter latency periods
10
Q
4 amines
A
- Epinephrine & Norephinephrine
2. Triiodothryonine and Thyroxine
11
Q
amines are derived from
A
tyrosine
12
Q
Epinephrine and Norepinephrine
A
shortest latency and fastest acting
13
Q
Triiodothryonine and Thyroxine (T3/T4)
A
- use carrier proteins in blood
- receptors located inside nucleus
- use direct gene activation
- longest latency (days) and slowest acting (months)
14
Q
Peptides
A
- short amino acid chains (3-200)
- hypothalamus, pituitary, pancreas, heart, gut, and kidney hormones
15
Q
Eicosanoids
A
- derived from Arachidonic Acid
- local hormones
- mostly NOT secreted by glands
- 3 TYPES: Thromboxanes, Leukotrienes, Prostaglandins
16
Q
thromboxanes
A
-secreted by platelets; causes platlet aggregation
SOLUTION: blood thinner
17
Q
Leukotrienes
A
- secreted by WBCs and spleen
- inflammation
18
Q
Prostaglandins
A
- secreted by most cells upon membrane damage
- inflammation
- vasodilation
- sensitize spinal neurons to pain
- promote fever
19
Q
Many common pain relievers inhibit enzymes needed for Eicosanoid formation
A
- anti-inflammatory
- analegic
- antipyretic: fever reduction
- antithrombotic: reduce clotting
20
Q
Direct Gene Activation formation is used by
A
steroid hormones
- freely pass through target cell membrane because fat soluble
- attach to intracellular receptor
- HRC enters nucleus and gene activation
- transcription and translation
- resultant protesins
21
Q
Direct Gene Activation results in
A
transcription of mRNA and translation of mRNA into proteins
22
Q
Resultant proteins in Direct gene Activation cause
A
cellular effects
23
Q
Second Messenger System Mechanism is used with
A
MOST non-steroid hormones
- cant cross cell membrane because water soluble
- attach to receptor on target cell surface
- HRC activates a G protein in the cell membrane
- G protein triggers reactions that lead to the formation of an intracellular 2nd messenger
- 2 messenger then causes a physiological response within a cell
24
Q
cAMP
A
- most common and studied 2nd messenger
- G Protein activates adenylate cyclase catalyzing reaction of AP—-> cAMP
25
examples of second messengers
- cAMP
- cGMP
- calmodulin
- inositoitriphosphate (ITP)
- diacylglycerol (DAG)
- calcium ions
26
tropic
one hormone causes the release of another hormone
27
Negative Feedback System
- hormone secreted in response to a homeostatic imbalance
- hormone acts to restore homeostasis
- restoration of homeostasis inhibits further hormone secretion
28
Postive Feedback Loops
- homeostatic imbalance triggers hormonal release
- hormonal action triggers hormonal release
- used for amplification within a larger negative feedback system
29
examples of positive feedback loops
LH during ovulation
| oxytocin during parturition
30
Down-regulation/desensitization
target cell decreases number of receptors available for a hormone
31
Up-regulation/ sensitization
target cell increases number of receptors available for a hormone
32
2 factors that determine hormonal activity
1. Levels of Circulating Hormone
| 2. The number of available receptors on the target organ
33
Hypothalamus
control center of hypothalamus
34
What does Antidiuretic Hormone (ADH) do?
- posterior pituitary
- promotes H20 conservation/retention by directly causing reabsorption of H2O from kidney tubules into capillaries to maintain plasma volume
- faster water hormone
- elevated up to 48 hours. post-exercise
35
2 mechanisms of action from ADH
1. Osmoreceptors in hypothalamus detect hemoconcentration. When hemoconcentrated, posterior releases ADH. ADH causes H2O reabsorption at kidneys into bloodstream (increase PV) restoring osmolality to normal
2. Atria, carotid, and pulmonary arteries and aorta contain baroreceptos. When decreased blood pressure, baroreceptors are stimulated causing ADH secretion. ADH causes reabsorption of H2O into blood, increases plasma volume and therefore blood pressure
36
prolactin
- ALL stimulates lipolysis
- chronically high levels may lead to reproductive consequences in males and females
- fasting/high fat diets stimulate prolactin release
37
what are endorphins?
endogenous opioid mood-altering and analgesic neurotransmitters and neurohormones
38
"Runner's High"
caused by endorphins
decrease anxiety, exhilaration, euphoria, increase pain tolerance, improved appetite control, decrease tension, anger, and confusion
39
2 training effects of endorphins
1. training increase opioid produced, so decrease levels needed to induce a specific eggiest
2. in trained person, opioids produced during exercise degrade more slowly, increase tolerance tolerance for prolonged exercise
40
Endorphins are a ________ addiction
"positive addiction
41
Anterior Pituitary
- releases its hormones in response to releasing/inhibiting factors from the hypothalamus
- prolactin, TSH, FSH, LH, ACTH, MSH, Endorphins, and GH (all tropic)
42
Thyroid Stimulating Hormone (TSH) (Thyropin)
-stimulates production and release of thyroid hormones and maintains normal growth and development of thyroid
43
Adrenocorticotropic Hormone (ACTH)
-stimulates production and secretion of hormones from adrenal cortex, especially cortisol
44
IGFs
Insulin-like growth hormones (somatomedin)
45
Major effects of Growth hormone
- increase fuel availability, sparing glucose for brain
- increase fat use
- decrease CHO use (the brain really like CHO)
- promotes favorable body composition by increasing Lean Body Mass and decreasing Fat Mass
46
Growth Hormone secretion falls about ___% of adolescent levels by old age, after adolescence
25
47
Why is Growth Hormone used as an Ergongenic Aid?
to enhance sports performance
48
Growth Hormone changes with age and used as an anti aging drug
accelerated with age, and increases energy with therapy
49
Which is greater within the growth hormone? Collagen growth or contractile growth?
Collagen growth is greater than contractile growth
50
low GH in children
Hypopituitary Dwarfism
51
low GH in adulrs
Simmond's Disease
| -premature aging due to tissue atrophy
52
how is Simmond's Disease treated?
with right (injected)
53
T3/T4
-large stores
(functions same, only differ in rapidity and intensity of action)
-T4-90% release
-T3-90% activity
-use plasma proteins, transported into target cell, use direct gene activation
-long latency, slowest acting
-increase MR of most tissues, through increase enzyme activity
-Hyperthyroidism
-Hypothyroidism
54
Hyperthyroidism
symptoms include
- high BMR
- increase Tb
- heat intolerance
- increased appetite
- weight loss
- increase/high blood pressure
- enhanced fuel catabolism
- muscle atrophy
- decrease/low ovarian function
- exhausted
- but can't sleep well, bug eyes
55
Hypothyroidism
- symptoms include low BMR
- decrease Tb
- decrease appetite
- weight gain
- decrease glucose metabolism
- high cholesterol
- arteriosclerosis
- ovarian function
- sleepiness
- husky voice
- poor hearing
- puffy/droopy eyes
56
incidence of disease (problems) and types in men vs. women
- 90% of thyroid disease occur in women
- -90% of thyroid diseases in men are cancerous
- -90% of thyroid diseases in women are benign
57
stimulus for calcitonin and PTH
-stimulated by high plasma Ca++
58
action of calcitonin and PTH
-acts to decrease plasma Ca++
59
PTH and bone remodeling
-stimulated by low plasma Ca++
-acts in increase plasma Ca++
-regulates plasma Pi
-targets bone and kidney
BONE: inhibits osteoclast activity. Osteoblast activity predominates, favoring deposition of Ca++ salts in bone
-opposition of calcitonin
-exercise increase PTH levels
--provides raw material for bone remodeling
-no training effect
60
Adrenal Cortex secretes over ___ cortiosteriods
30
61
mineralcorticoids
maintain electrolytes (mineral) balance (1 degree aldosterone)
62
glucocorticoids
maintain blood glucose (1 degree) cortisol
63
gonadocorticoids
same as hormones from gonads
64
catecholamines
- adrenal nedulla
- hormones and neurotransmitters
- epinephrine: mainly hormone
- norepinephrine: mainly neurotransmitter
65
80% of hormonal release is
Epinephrine
66
20% of hormonal release is
Norephrine
67
Effect od E/NE similar to SNS effects and their release is usually triggered by
SNS stimulation
68
Actions of Aldosterone
- promotes Na+ absorption from renal tubules. H2O follows Na+
- promotes K+ excretion and regulated pH because kidney exchange either K+ or H+ for Na+
69
Renin-Angiotensin System
- low plasma volume or blood pressure in renal artery or increase SNS stimulation to kidneys to release renin
- renin enters the blood where it converts angiotensinogen to angiotensin I
- in the endothelium of lung blood vessels, angiotensin converting enzyme (ACE) catalyzes the conversion of angiotensin I to angiotensin II
- angiotensin II causes strong vasoconstriction and aldosterone release
- vasoconstriction will increase blood pressure
- aldosterone will inquire Na+ and H2O which in turn increase plasma volume and blood pressure
70
Aldosterone is slower acting than ADH
-ADH is more active during exercise while aldosterone more active post-exercise, unless exercise duration > 1 hr.
71
Aldosterone elevation post-exercise
- Both ADH and aldosterone elevated 12-48 hours post exercise, decrease urine production and protect from dehydration
- responsible for increase plasma volume with training
- "Sports Anemia"-False + for anemia in athletes
72
Cortisol
- diurnal variations
- stress triggers secretion
- used as inflammatory
- tapering
- increased incidence of URTIs
73
Actions of Cortisol
-maintain plasma glucose by increasing availability of all fuels
74
increased incidence of URTIs in Cortisol
very high levels occur following long duration running
75
___- shaped relationship between exercise and incidence of URTIs
J-shaped
76
Open window Hypothesis
large increase in training or actual competition exposes highly trained athletes to abnormal stress that temporarily, but severely, decrease immune function
- 3-72 hours post exercise, with symptoms starting in 1-2 weeks
- EXAMPLE: marathoners at high risk after race
- --risk varies inversely with race times
77
Mainly hormone
Epinephrine
78
Mainly neurotransmitter
Norepinephrine
