chapter 74 Flashcards
(156 cards)
1
Q
What does endocrine mean?
A
Internally secreting. It is an information signaling system.
2
Q
The edocrine system uses what to do what?
A
Uses ductless glands that secrete hormones into bloodstream that effect changes downstream.
3
Q
What are the 2 systems of control in the body?
A
Endocrine and Nervous system.
4
Q
What is the classic endocrine signaling?
A
Hormones travel to distant organs to regulate the target organs function. They can be very specific to certain organs or they can act systemically.
5
Q
What is neuroendocrine?
A
Another type of signaling that is not classical endocrine that is released by neurons.
6
Q
What is paracrine?
A
A type of signaling that is not a classical endocrine but it affects function of neighboring cells.
7
Q
What is Autocrine?
A
A type of signaling that is not a classical endocrine but it affects function of the same cell.
8
Q
What is cytokines?
A
endocrine hormones.
9
Q
How far will endocrine actions travel?
A
To distant target cells.
10
Q
How far will paracrine actions travel?
A
Target cells in the neighborhood.
11
Q
How far will autocrine actions travel?
A
Acts on the same cell that produced it.
12
Q
What will lead to hormone secretion?
A
A change in internal and/or external environment.
13
Q
What is it called when the hormone travels through our vascular system to target cell where it elicits an action at the cellular level to restore and maintain the normal dynamics?
A
Homeodynamics.
14
Q
What is the opposite of homeostasis?
A
Static because homeostasis is very dynamic.
15
Q
Name 4 major body functions that are regulated by endocrine signaling?
A
metabolism, growth, reproduction, water & electrolyte balance.
16
Q
Name the 3 general chemical structures released by endocrine systems?
A
- Proteins and polypeptides. 2. Steroids. 3. Amine derivatives.
17
Q
Steroids are synthesized via what?
A
Cholesterol.
18
Q
Amine derivatives are what?
A
They are like proteins but derived from Amino Acids.
19
Q
What hormones are proteins (aka peptides) or polypeptides?
A
Pituitary, parathyroid and pancreatic.
20
Q
Where are steroids produced at?
A
Adrenals, ovaries, testes, and placenta.
21
Q
Where are amine derivatives secreted from?
A
From thyroid and adrenal medullae.
22
Q
What are the sizes of peptide/protein hormones?
A
3-100’s of Amino Acids in size.
23
Q
What part of cells will peptide/protein hormones be made at?
A
Rough endoplasmic reticulum.
24
Q
How are the peptide/protein hormones made?
A
active.
25
Hormones are encoded by genes that transcribes the hormones blueprint to what?
mRNA
26
The mRNA does what?
Translates the blueprints into protein precursors called preprohormone.
27
The preprohormone is sent to the Rough ER where it does what?
It is cleaved to make the prohormone.
28
The prohormone is then sent where? What happens here?
hormone.
29
Are peptide hormone water soulable?
Yes.
30
Will peptide hormones need help crossing the cell membrane?
Yes.
31
Most hormones are what?
Peptides or polypeptides.
32
When peptide hormones are needed how will they get out of cells?
Secretory vesicles fuse to the cells membrane, and with the appropriate signal exocytosis occurs.
33
Can a prohormone be secreted?
Yes and then it is converted into its active form by enzymes.
34
Where will enzymes that activate prohormones be made at?
Kidney and lungs.
35
Where will steroid hormones come from?
All are synthesized from cholesterol.
36
How are steroid hormones stored?
They are not usually stored.
37
Are steroid hormones water or lipid soluble?
Lipid soluable.
38
Will steroid hormones need help passing through the cell membrane?
No.
39
Since steriod hormones are not stored how are the precursors stored?
Steroid secreting hormone cells have large stores of cholesterol in cytoplasmic vacuoles.
40
What causes the cholesterol to be synthesized into the requred steroid?
A stimulus.
41
Where will most of the Cholesterol come from that is used to make steroid hormones?
From plasma and not from dietary intake.
42
What type of cholesterol can steroid producing cells make?
De novo cholesterol.
43
Where will de novo cholesterol synthesis happen at?
cytosol of steroid producing cells.
44
The de novo cholesterol making process is similar to what?
The keogenic pathway.
45
What is needed to make de novo cholesterol?
NADPH and ATP.
46
How regulated is the making of de novo cholesterol?
Highly because of all the players involved.
47
Name 5 types of steroid hormones?
glucocoricoids, mineralcorticoids, androgens, estrogens, progestins.
48
Vitamin D is not really a vitamin why?
it is derived from cholesterol, but it can be synthesized by de novo cholesterol.
49
What will Vitamin D act as?
A true hormone.
50
Steroid hormones are synthesized for release.
Immediate.
51
When are steroid hormones synthesized?
On an as-needed basis.
52
Where are enzymes that produce steroid hormones from cholesterol found at?
In mitochondria and endoplasmic reticulum.
53
How will steroid hormones move through the blood?
They are not water soluable so they need to be bound to globulins (proteins).
54
Name the sex hormone binding golbulins?
Testosterone & estradiol.
55
Name the coricosteroid binding golbulin?
Cortisol.
56
What is the rate limiting step in steroid hormone synthesis?
Transport of free cholesterol from cytoplasm into the mitochondria.
57
What are the 2 groups of Hormones derived from amino acid tyrosine?
thryoid and catecholamines.
58
What is a thyroid hormone?
A double tyrosine with 3 or 4 iodine atoms.
59
What are the 2 thyroid hormones?
T3- has 3 iodine aka triiodothyronine, and T4 has 4 iodine aka thyroxine.
60
Where are thyroid hormones made at?
By thyroid gland.
61
Are thyroid hormones water or lipid soluable?
Lipid soluable.
62
Thyroid hormones can pass through cell membranes but how will they pass through plasma?
They bind to thyroxin binding globulin.
63
What are catecholamines?
Neurohormones and neurotransmitters.
64
What are the major catecholamines?
Epinephrine and norepinephrine.
65
Where are catecholamines made at?
Adrenal medulla.
66
Are catecholamines water or lipid soluable?
Water.
67
How will catecholamines act?
Like peptide hormones in secretion and actions.
68
Name 3 other hormones that are synthesized from amino acids?
Tryptophan, glitamic acid, and tyrosine.
69
What are eicosanoids?
fatty acid signaling molecules omega-3 or omega-6.
70
Eicosanoids are made from what?
Polyunsaturated fatty acids.
71
What 3 processes will eicosanoids exert control over?
1. Inflammation. 2. Immunity. 3. Act as CNS messengers.
72
What is the most abundant eixosanoid precusor?
Arachidonic acid.
73
How long will eicosanoids remain active?
Only a few seconds because they are rapidly inactivated by being metabolized.
74
What type of eicosanoid is generally pro-inflammatory?
Omega-6.
75
What will anti-inflammatory drugs do?
They act by downregulating eixosanoid synthesis.
76
How is the endocrine system organized?
Top down.
77
The hypothalamus produces what?
Releasing and inhibiting factors.
78
What will the releasing and inhibiting factors produced in the hypothalamus do?
They stimulate or inhibit the production of anterior pituitary hormones.
79
What will anterior pituitary hormones act on?
They act on peripheral endocrine gland stimulating release of a 3rd hormone.
80
Where are posterior pituitary hormones made at?
In neuronal cell bodies in the hypothalamus.
81
Hormones from anterior pituitary glands travel to target endocrine organs to stimulate secretion of more hormone messengers that then travel where?
To target cells that elicte cellular actions.
82
A cell is called a target when?
When it has specific receptor for a particular hormone.
83
How will sensing and signaling of endocrine system work?
1. biological need is sensed. 2. endocrine system gland sends out a signal in the form of a hormone. 3. Target cells acts to address the biological need. 4. A feedback loop often will signal the glands to stop producing the hormone once homeostasis is reached.
84
Physiologic effects of hormones depends largely on what?
Their concentration in blood, extracellular fluid, and number of receptors present on target cells.
85
Hormone levels that are too low or high can lead to what?
disease.
86
What happens when there is a chronically high hormone concentration?
Downregulation of hormone receptors.
87
What is the most highly regulated aspect of endocrine control?
synthesis and secretion.
88
What is the most common feedback control?
Negative feedback.
89
What is negative and what is postive feedback control of endocrine systems?
Postitive- the action of a hormone causes increased secretino of the hormone. Negative- the action of the hormone triggers the suppression of fruther hormone release.
90
What determines the rate of delivery?
The amount of blood flow.
91
Protein bound hormones are cleared fast or slow?
Slow.
92
Name the different inputs to endocrine cells?
neurons, hormones, ions, organic nutrients.
93
The hypothalamus is the link between what 2 systems?
the nervous and enodcrine.
94
How is the hypothalamus the link between the nervous and endocrine systems?
neural input to the hypothalamus stimulates synthesis and secretion of releasing factors which stimulate pituitary hormone productin and release.
95
Chronotropic control of endocrine system is aka?
Endogenous neuronal rhythmicity.
96
What is Circadian rhythms?
Hormones are released at set interval every day.
97
What is the biological circadian rhytm that syncronizes with the day-night cycle called?
Diurinal rhythms.
98
The sleep-wake cycle can be different than the diurnal rhythm for who?
People who have sleep problems or who work late-night shifts.
99
What is the key player in seasonal rhythm?
Melatonin.
100
What do we call episodes with a frequency of about one hour?
Circhoral.
101
What do we call episodes with a frequency longer than one hour but shorter than 24 hours?
Ultradian.
102
What do we call episodes with a frequency of 24 hours?
Cicradian.
103
Physiological importance of pulsatile hormone release was demonstrated by what?
Gondadotropin releasing hormone (GnRH) infusion.
104
How many receptors will target cells have?
2,000-100,000
105
What are the 3 locations of receptors?
1. Cell membrane. 2. In cell cytoplasm. 3. In cell nucleus.
106
The receptors are proteins that are specific how many hormones?
only 1.
107
What are Ion channel-linked receptors like?
Neurotransmitter binds to receptor this creates a conformational change which opens/closes the ion channels. This allows info to pass through.
108
What are enzyme-linked receptors like?
Hormone binds to receptor and activates or inactivates intracellular enzyme which catalyze second messengers which leads to change in cell function.
109
What are GTP-binding receptors like?
leads to intracellular signaling that opens/closes ion channels or changes enzyme activity and this changes cell functions.
110
What are intracellular receptors like?
Steroid hormones cross cell membrane and bind with intracellular receptors then the hormone and the complex bind in DNA and activate transcription of genes/formation of mRNA.
111
In general second messengers bind with what type of hormones?
Water soluable.
112
How will the second messenger cAMP work?
Hormone binds to a receptor and produces a conformational change in the receptor. This activates G-stimulating protein which allows for the intracellular stimulation of adenyl cyclase. This converts ATP to cAMP which activates cAMP-dependent protein kinases. These kinases allow genes to express themselves leading to phosphorylation of specific proteins.
113
How will the second messenger Phospholipase C work?
stimulating protein which leads to the intracellular stimulation of Phospholipase C. This in turn leads to catabolic breakdown of cell membrane phospholipids (PIPA2) and formation of 2nd messenger products IP3 and DAG.
114
What will IP3 do?
cell secretion.
115
What will DAG do?
Produces an activation of protein kinase C leading to protein phosphorylation and arachindonic acid conversion to prostaglandins.
116
What happens when calcium binds to calmodulin?
This leads to activation/inhibition of protein kinases which in turn leads to a cell response.
117
Genetic regulation is done by what type of hormone?
Steroid hormones.
118
Where are receptors for water soluble hormones found at?
ON the surface of target cell.
119
Where are receptors for the lipid soulble hormones found at?
IN the nucleus of target cell.
120
Name 4 types of second messenger systems?
1. cAMP. 2. cGMP. 3. Calcium calmodulin. 4. Phospholipase C.
121
What are changes like that are made by second messengers?
Rapid and strong because of amplification.
122
How fast is the response from a steroid hormone and why?
It is slow due to required transcription/translation.
123
what does an agonist ligand do?
binds to r/c --> hormone response
124
What does an agonist ligand do?
binds to r/e to activate a hormone response.
125
Which hormones are agonist?
all main hormones
126
what does an antagonist ligand do?
bind to a r/c and inhibit a hormone response
127
How does the antagonist ligand work?
by blocking the binding of agonist ligands. therefore preventing their actions
128
are circulating levels of antagonist ligands high or low?
too low to be effective
129
what is a partial agonist partial antagonist ligand?
ligands whose actions are less than a full agonists actions.
130
What happens if concentrations of a partial agonist antagonist ligand is high?
block full agonist actions and act as an antagonist
131
What are mixed agonist antagonist?
compounds that act in different ways through the same r/c. agonist or antagonist action depends on the contect
132
What are inactive ligands?
do not bind r/c
133
Actions of hormones affect what?
all tissues and organ systems
134
What are the actions of developmental hormones?
defects can cause defects
135
How do endocrine glands grow?
growth is linear and cells proliferate readily
136
Name 4 kinds of endocrine cancers?
breast, prostate, endometrial, thyroid
137
What are the actions of CNS hormones?
regulate behavior and cognitive function
138
How can endocrine disorders lead to CNS symptoms?
ex: hyperthyroidism --> depression
139
What are the actions of metabolism hormones?
regulate metabolism at all times
140
What are the actions of CVS/Renal hormones?
- affects on HR, contractility, and BP
| - influence renal blood flow, GFR, transport of water ions and chemicals
141
What are the actions of mineral and water metabolism hormones?
Vasopressin regulated serum osmolality and water excretion. others regulate ionic balance
142
What are the actions of skeletal function hormones
continuous remodeling of bone
| prevention of osteoporosis.
143
What are the actions of reproductive hormones?
- regulation & development of sexual characteristics
- maturation of the repro tract and onset of puberty
- pregnancy, labor and lactation
144
What are the actions of immune hormones?
- modulates immune function and inflammation
- autoimmune disease (female > male)
- pregnancy suppresses cellular but not humoral response.
145
What 3 things do endocrine disorders result from regarding hormones?
- deficiency
- excess
- resistance
146
WHat is deficiency of hormones due to?
Usually - destructive processes at the gland where the hormone is produced
147
What else can deficiency also arise from?
genetic defects in hormone production
148
What is testicular feminization syndrome? (don't say "its what Jake has")
a genetic defect in the production of the main androgen r/c leading to the outward appearance of a female with no viable uterus and fallopian tubes. It's also what Jake has.
149
What is Cushing's syndrome?
pituitary tumor leading to excess cortisol secretion
150
What does overproduction of tropic hormones lead to?
overstimulation of target gland
151
What do activation mutations of cell surface receptors cause?
aberrant stimulation of hormone production by endocrine gland
152
What is McCune-Albright syndrome?
Precocious puberty. usually caused by activating mutation which turns the gene for gonadotropin production irreversibly on.
153
What do malignant transformations of non-endocrine tissues lead to?
lack of differentiation --> ectopic production of hormones.
154
What do anti-receptors antibodies stimulate?
the receptor instead of blocking it (hyperthyroidism)
155
What do alterations of r/c number and function result in?
endocrine disorders
156
What is downregulation?
an aberrant increase in level of a specific hormone will cause a decrease in available r/c's (type 2 diabetes)
