PSIO202 Exam 3 Endocrine Flashcards
1
Q
What are the similarities between the nervous and endocrine system?
A
control and coordinate body activities, chemical messengers for intercellular communication
2
Q
What are the three major differences between nervous and endocrine systems?
A
nature of the message (actional potentials and neurotransmitters vs. hormones)
message speed (nervous is milliseconds to seconds, endocrine is seconds to minutes)
message duration (nervous also only lasts milliseconds to seconds, endocrine lasts days to weeks)
3
Q
Nervous system and endocrine system release different messages, but they can affect the same…
A
target cells
4
Q
What are the 5 endocrine glands?
A
pituitary gland, thyroid, parathyroid, adrenal, and pineal
5
Q
What are other organs and tissues with endocrine cells?
A
hypothalamus, thymus, pancreas, ovaries and testes, lots of others (kidneys, renal, liver, stomach, SI, heart, skin, adipose tissue)
6
Q
The endocrine system contains any tissue or organ that…….
A
contains endocrine cells
7
Q
What are exocrine vs endocrine glands? Are exocrine included in the endocrine system?
A
exocrine - secrete products into ducts and lumens or to the outer surface of the body (including digestion, reproduction, etc.)
**not included in endocrine system
endocrine - secrete products into interstitial fluid (which diffuses into the blood) or directly into the blood
8
Q
What are the other terms for hormones, and what is the definition?
A
chemical messengers (or mediator molecules)
that are released in one part of the body and regulate activity in other parts of the body
9
Q
Describe local vs. circulating, and autocrine vs. paracrine vs. endocrine
A
local - effect cells nearby (autocrine is when the hormone binds to receptors on itself, and paracrine is when they bind to cells very close)
circulating - endocrine is when the hormones travel in the blood to far away cells
10
Q
Can local hormones can act as autocrine and paracrine at the same time?
A
yes
11
Q
What are the two main types of circulating hormones?
A
water soluble and lipid soluble
12
Q
Since hormones have to bind to receptors to cause an effect, what are the three ways the effect can be amplified?
A
increase the concentration of the hormone
increase the number of receptors
increase the affinity of the hormone for the receptor
13
Q
What is the difference in how lipid soluble and water soluble hormones are transported?
A
lipid soluble - bound to transport proteins for transport in body fluids
water soluble - freely dissolved in body fluids
14
Q
What are the two types of lipid soluble hormones?
A
steroid hormones
thyroid hormones
15
Q
What are steroid hormones? What are some examples?
A
lipids soluble hormones that are derived from cholesterol
cortisol, testosterone, estrogens, progesterone, aldosterone
16
Q
What are thyroid hormones? What are some examples?
A
lipid soluble hormones that are composed of a tyrosine ring with attached iodines
T3 or T4
17
Q
Lipid soluble hormones are important because they can withstand….
A
digestion
18
Q
What are the two types of water soluble hormones?
A
peptide and protein hormones
biogenic amines
19
Q
What are peptide and protein hormones? What are some examples?
A
water soluble hormones that are composed of chains of amino acids
they are hypothalamic releasing and inhibiting hormones
ADH, oxytocin, hGH, TSH, ACTH, insulin, glucagon, EPO
20
Q
What are biogenic amines? What are some examples?
A
water soluble hormones that are small and composed of modified amino acids
catecholamines (aka neurotransmitters)- NE, epi, dopamine
serotonin, melatonin, histamine
21
Q
Hormones are released from glands in response to —— or ——- changes.
A
internal or external
22
Q
Hormones produce ——-reaching effects on —– target tissues.
A
wide-reaching effects on multiple target tissues
23
Q
What are some general ways that hormones regulate organ system function?
A
metabolic pathways, biological clock, contraction of cardiac and smooth muscle, glandular secretion, immune functions, growth and development, reproduction (basically everything)
24
Q
What is the shape of a time graph for a negative feedback loop?
A
wave up and down, up and down, over and over
25
Hormones will only affect target cells with specific membrane or intracellular proteins called ------- ---------.
All hormones have at least (#) target cell.
hormone receptors
1
26
How do water and lipid soluble hormones leave the secretory cell?
How do water and lipid soluble hormones travel?
Where are the receptors for water and lipid soluble hormones?
water - exocytosis ; lipid - diffusion
water - freely ; lipid - bound to transport protein
water - cell membrane ; lipid - inside cell
27
What are 4 ways that a cell can respond to a hormone binding to a receptor?
synthesis of new molecules, alteration of existing molecules, change in membrane permeability, altered rates of reaction
28
Different target cells can respond to the same hormone...
in different ways
29
Describe steroid hormone action from secretion to effect. Is it fast or slow?
leave the secretory cells by diffusion, require transport protein, diffuse freely into the target cell, intracellular receptor, and change the specific gene expression
slow
30
Describe peptide hormone action from secretion to effect. Is it fast or slow?
leave the secretory cell by exocytosis, no transport protein, bind to cell surface receptor, evoke changes in existing proteins via second messengers (often alter phosphorylation state of proteins)
fast
31
A "first messenger" water soluble hormone binding to a receptor will (increase and/or decrease) intracellular second messenger.
can increase or decrease the second messenger
32
Is the second messenger that a hormone causes always the same?
no, it can be different for different target cells
33
What do second messengers initiate?
a series of biochemical reactions (usually involving phosphorylation or dephosphorylation) in the target cell
34
The hypothalamus receives input from the...
cortex, thalamus, limbic system and internal organs
35
The hypothalamus links the ------- and -------- environment and the -------- system.
external internal environment
endocrine system
36
The hypothalamus and pituitary gland together control almost all aspects of...
growth, development, metabolism, and homeostasis
37
How are the anterior and posterior pituitary connected to the hypothalamus?
anterior - connected by blood supply but not by the infundibulum
posterior - not connected by blood but is connected by the infundibulum
38
What type of tissue is int he anterior and posterior pituitary?
anterior - glandular
posterior - nervous
39
What supplies the posterior pituitary with blood, and what drains it? What connects those vessels?
the inferior hypophyseal artery supplies it, the posterior hypophyseal veins drain it, and they are connected by the capillary plexus of the infundibular process
40
What is the blood flow path for the anterior pituitary?
blood comes in through the superior hypophyseal artery, enters the primary plexus of the hypophyseal portal system, then moves down to the anterior pituitary via the hypophyseal portal veins, goes through the secondary plexus of the hypophyseal portal system, and then drains through the anterior hypophyseal veins
41
What are the two main ways the hypothalamus can control the pituitary?
anterior - release releasing or inhibiting hormones that travel through the blood to the anterior pit.
posterior - hypothalamus makes hormones that are sent to the posterior pit. to be released into circulation
42
After the hypothalamus releases hormones which act on the anterior pituitary, what does the anterior pituitary do?
5 types of anterior pituitary cells can release more/less of 7 tropic hormones into the blood
43
What occurs at both capillary plexus that link the hypothalamus and anterior pituitary?
primary - releasing and inhibiting hormones from the hypothalamus enter the blood to travel to the ant. pit.
secondary - those releasing and inhibiting hormones reach the cells in the ant. pit. causing them to release more/less hormones
44
What are the 5 cells types in the anterior pituitary?
somatotrophs, thyrotrophs, lactotrophs, gonadotrophs, and corticotrophs
45
What hormone is released by somatotrophs, and what hormones stimulate the release/inhibition?
hGH
stimulated by GHRH
inhibited by GHIH
46
What hormone is released by thyrotrophs, and what hormones stimulate the release/inhibition?
TSH
stimulated by TRH
inhibited by GHIH
47
What hormone is released by lactotrophs, and what hormones stimulate the release/inhibition?
PRL
stimulated by PRH
inhibited by PIH (dopamine)
48
What hormone is released by gonadotrophs, and what hormones stimulate the release/inhibition?
FSH and LH
stimulated by GnRH
49
What hormone is released by corticotrophs, and what hormones stimulate the release/inhibition?
ACTH and MSH
stimulated by CRH
only MSH are inhibited by PIH (dopamine)
50
What does an increase in hGH cause?
How do IGFs help growth?
synthesis of insulin like growth factors (IGFs), which:
- increases cell growth and differentiation by increasing the uptake of amino acids and synthesis of proteins
- stimulate lipolysis of adipose tissue
- decrease glucose use so that there is more glucose to supply the brain
51
What are the target tissues of hGH/somatotrophs?
liver, skeletal muscle, cartilage, and bone
52
What are the stimuli for GHRH release?
hypoglycemia, deep sleep, decreased fatty acids and increased amino acids in the blood, increased sympathetic stimulation
53
What are the stimuli for GHIH release?
hyperglycemia, REM sleep, increased fatty acids and decreased amino acids, obesity, low thyroid hormones, and high hGH
54
What are the target tissues/effects of FSH?
women - stimulate secretion of estrogen and formation of follicles in the ovary
men - stimulate sperm production in the testes
55
What are the target tissues/effects of LH?
women - secretion of estrogen and progesterone, ovulation, formation of corpus luteum
men - testosterone
56
What inhibits LH production?
the testosterone, estrogen, and progesterone that are released when LH is stimulated.
57
What are the target tissues/effects of PRL?
Besides PRH, what else can increase PRL?
target mammary gladns for breast milk production
suckling reduces inhibition of PRL by PIH
58
What are the target tissues/effects of MSH?
increases skin pigmentation in the skin
59
What are the target tissues/effects of ACTH?
stimulates the release of glucocorticosteroids (like cortisol) from the adrenal cortex
60
What inhibits the corticotrophs from releasing ACTH?
cortisol that is produced from the adrenal glands when stimulated by ACTH
61
What are the target tissues/effects of TSH?
stimulates synthesis and secretion of T3 and T4 thyroid hormones from the thyroid, which stimulate the metabolic rate
62
What hormones from the anterior pit. do not have a specific inhibiting hormone?
FSH, LH, and ACTH
63
What hormones from the anterior pituitary are NOT tropic?
PRL and MSH
64
What is the difference in how the hypothalamus communicates with the anterior ad posterior pituitary?
anterior - capillary plexus allow releasing and inihibiting hormones released from the hypothalamus to travel through blood, down to the anterior pit., where tropic hormones are created and released out to tissues
posterior - hypothalamohypophyseal tracts connect the hypothalamus and posterior pit. so that the hormones are created in the hypothalamus and travel down to the posterior pit. to be directly released into systemic circulation
65
Which part(s) of the pituitary synthesize hormones?
anterior only
66
How many axon terminals travel down to the posterior pituitary? How many hormones travel down these terminatls? What type of hormones are they?
2 axon terminals, transport the peptide hormones OT and ADH
67
In what ways does the posterior pituitary resemble neural tissue?
glial cells, nerve fibers, nerve endings, and neurosecretory vesicles
68
Where is ADH synthesized, and what signals it to be produced?
in the supraoptic nucleus of the hypothalamus
made in response to signals from osmoreceptors which monitor blood hydration status
69
What are the actions and target tissues of ADH?
kidneys - increase water reabsorption, decreasing urine production
sweat glands - prevents water loss
vessels - "vasopressin," cause constriction of aterioles
70
What is the general desponse of ADH production during dehydration/high osmolarity and overhydration/low osmolarity?
dehydration/high osmo - ADH released by posterior pit.
overhydration/low osmo - ADH release is inhibited
71
What are the two other things we learned can affect ADH function?
alcohol - stops ADH release
diabetes insipidus - lack of ADH or nonfunctional ADH receptors, inability of kidneys to conserve H2O, and excessive urination (2 L/day to 20 L/day)
72
Where is OT produced, and what are the target tissues/effects? Positive or negative feedback?
produced in the paraventricular nucleus of the hypothalamus
uterus: during labor
mammary glands: after delivery in response to suckling
positive feedback
73
Explain the positive feedback loop for the regulation of uterine contraction during childbirth. Include how it ends.
baby's head stretches cervix
OT released
uterine smooth muscle contracts
baby's head pushed harder on cervix = more stretch
more OT
repeat until baby is born, and loop ends because there is no more pressure on the cervix
74
Explain the negative feedback loop for the regulation of mammary gland function.
suckling, hearing babby cry cause OT release
Smooth muscle contraction (milk ejection)
Baby is fed and stops crying
no more OT release
no more milk ejection
75
Explain the meaning of lactation, as well as the difference between PRL and OT.
lactation: milk production and ejection
PRL: milk production
OT: milk ejection
76
Explain the histology of a thryoid follicle.
interior solid part - thyroglobulin (TGB)
entire circular complex - follicle
First layer of cells around a follicle - follicular cells
Other cells not in the ring - parafollicular cells
outermost membrane (outside first layer of cells) - basement membrane
77
What cells produces the thyroid hormones, and what are the hormones produced?
follicular cells produce T3 (triiodothyronine) and T4 (thyroxine), parafollicular cells produce calcitonin
78
What are the basic steps for forming T3 and T4?
1. iodide trapping into follicular cells
2. synthesize and release thyroglobulin (TGB) into colloid
3. oxidation of iodide
4. iodination of TGB tyrosine in colloid
5. formation of T3 and T$ by combining T1 and T2
6. TGB is taken in and digested by follicle cells
7. T3 and T4 are secreted into the blood
8. bind and transport T3 and T4 on a TBG (thyroxine-binding globulin) carrier
79
Which is the active form of thyroid hormone?
T3
80
Briefly, what are the 4 actions of thyroid hormones?
increase basal metabolic rate
increase Na+/K+ ATPase
enhance actions of the sympathetic nervous system (up regulate beta receptors)
stimulate growth
81
How do thyroid hormones increase the basal metabolic rate?
increase cellular use of O2 to produce ATP by breaking down glucose, fatty acids, and triglycerides
82
How do thyroid hormones affect the Na+/K+ ATPase?
they increase synthesis of Na+/K+ ATPase, resulting in more ATP used to pump ions, which produces heat and raises body temp (calorigenic effect)
83
How do thyroid hormones enhance sympathetic nervous system actions?
They bind to beta-receptors (mimicking neurotransmitters) and increase heart rate, contractility, and BP
84
When and where do thyroid hormones stimulate growth?
in the nervous and skeletal systems primarily during development
85
What does hyposecretion of thyroid hormones cause, both during development and in adults?
development - dwarfism and severe mental retardation (congenital hypothyroidism or cretinism)
adults - edema, low heart rate, muscle weakness, sensitivity to cold, low body temp, weight gain, mental dullness
86
How does hypersecretion of thyroid hormones impact adults?
Graves' Disease
weight loss, nervousness, tremors, increased heart rate and blood pressure, exophthalmos (edema behind eyes), high body temp, sweating
87
What causes a goiter?
low iodine ---> low T3 and T4 ---> higher TSH ---> thyroid growth
88
What are the parathyroid glads main targets and actions?
main goal: raise blood calcium
osteoclasts - increase activity
kidney - increase reabsoprtion of Ca++, inhibit reabsorption of phosphate, form calcitriol which causes the intestines to absorb Ca++ and Mg++
89
What do the parafollicular cells produce, and what effect does that have?
calcitonin, lower blood calcium by inhibiting osteoclasts
90
What do the parathyroid's chief cells produce, and what effect does this have?
PTH, raises blood calcium by stimulating osteoclasts
91
What do the follicular cells produce, and what effect does this have on calcium levels?
T3 and T4, no calcium effects
92
What happens if blood calcium is too high? Too low?
too high ----> thyroid gland parafollicular cells release calcitonin ----> inhibit osteoclasts and decrease reabsorption -----> calcium drops
too low -----> parathyroid gland chief cells release PTH ------> increase osteoclast activity, kidney reabsorption, and calcitriol in the intestine -----> increase calcium
93
What is the normal blood calcium level?
8.5-11 mgCa++ / 100 mL of blood
94
What are the layers of the adrenal gland from superficial to deep?
capsule, zona glomerulosa, zona fasciculata, zona reticularis, and adrenal medulla
95
What type of hormone does the zona glomerulosa produce, and what is the main example? What effects occur from this hormone?
mineralocorticoids
aldosterone
- increase absorption and reabsorption (GI and kidney) of Na+, Cl-, and water
- excretion of K+ and H+ from kidney
96
What is aldosteronism?
hypersecretion of mineralocorticoids, resulting in high BP from retention of Na+ and water
97
What type of hormone does the zona fasciculata produce, and what is the main example? What effects occur from this hormone?
glucocorticoids
cortisol (hydrocortisone)
- regulation of metabolism during stress by...
- increase protein catabolism and lipolysis
- promote gluconeogenesis
- resistance to stress by making nutrients available
- raise BP by increasing sensitivity to vasoconstrictor
98
What is the negative effect of cortisol, and how does it occur?
anti-inflammatory and immunosuppressive
- reduce histamine release
- decrease capillary permeability (less fluid can enter)
- decrease phagocytosis and WBC count
99
What is the pathology of Cushing's Syndrome, and what are some symptoms?
hypersecretion of glucocorticoids
redistribution of fat to the face, spindly arms and legs due to muscle loss, poor wound healing, and bruising easily
100
What is the pathology of Addison's Disease, and what are some symptoms?
hyposecretion of glucocorticoids and aldosterone
hypoglycemia, muscle weakness, low BP, dehydration, mimic skin darkening effect of MSH, potential cardiac arrest
101
What type of hormone does the zona reticularis produce, and what is the main example? What effects occur from this hormone?
androgens
DHEA
- sex drive in females
- form of estrogen for postmenopausal women
102
What does the adrenal medulla produce, and what are the effects? What cells produce hormones in the medulla?
chromaffin cells produce 80% epi and 20% norepi. which mimic the effects of sympathetic NS and cause fight or flight behavior (sympathomimetic)
103
Regarding stress responses, what is the overall difference between short term and long term stress responses?
short term - epi and norepi produced by the medulla
long term - mineralocorticoids and glucocorticoids produced by the zona glomerulosa and zona fasciculata
104
Regarding stress responses, how are the effects different for short term and long term stress?
short term - epi and norepi cause glycogen breakdown, increase blood glucose, increase blood pressure/breathing rate/metabolic rate, change in bloodflow patterns leading to increased alertness and decreased digestive/excretory/reproductive activity
long term -
aldosterone: retention of water and NA+, increase blood volume and blood pressure
cortisol: proteins and fats broken down, increase blood glucose, suppress immune system
105
In the pancreas, what are the cell types and what do they each produce?
alpha - glucagon
beta - insulin
delta - somatostatin
F cell - pancreatic polypeptide
106
What does somatostatin do? Where is it released, and what inhibits it?
it inhibits GH, insulin, and glucagon release
it is released by the delta cells of the pancreas
it is inhibited by the pancreatic polypeptide
107
What are the functions of the pancreatic polypeptide?
inhibit somatostatin release, gallbladder contraction, secretion of digestive enzymes from the pancreas
108
What is the pathway of response for low blood sugar?
glucagon acts on hepatocytes, they convert glycogen to glucose, glucose is released and raises blood glucose
109
What is the pathway of response for high blood sugar?
insulin acts on various cells:
- accelerate diffusion of glucose into cells
- speed conversion of glucose into glycogen
- increase synthesis of proteins and fatty acids
- slow glycogenolysis and gluconeogenesis
all cause blood glucose to fall
110
What are the main symptoms of diabetes mellitus? Why do these symptoms make sense?
excessive urine production (polyuria), excessive thirst (polydipsia), and excessive eating (polyphagia)
increase glucose stops the kidneys from absorbing water, so it all leaves the body through urination and then the person is thirsty too. High glucose also reduced protein breakdown, etc. so nutrition is lacking as well.
111
What are the differences in type 1 and type 2 diabetes mellitus?
type 1 - deficiency of insulin, typically juvenile onset
type 2 - decrease insulin sensitivity, typically adult onset
