The Endocrine System (ch18) Flashcards
1
Q
what are the physiological signals
A
electrical signals and chemical signals
2
Q
electrical signals
A
changes in the membrane potential of a cell
3
Q
chemical signals
A
- molecules secreted by cells into extracellular fluid
- reponsible for most communication within the body
- chemical signals act as ligands that bind to proteins to initiate a response
4
Q
molecules in nervous system
A
neurotransmitters released locally in response to nerve impulses
5
Q
molecules in endocrine system
A
hormones delivered to tissue throughout body by blood
6
Q
site of action for nervous system
A
close to site of release, at synapse; binds to receptors in postsynaptic membrane
7
Q
site of action for endocrine system
A
- far from site of release (usually); binds to receptors on or in target cells
8
Q
types of target cells in nervous system
A
- muscle cells, gland cells, other neurons
9
Q
types of target cells in endocrine system
A
- cells throughout body
10
Q
duration of action in nervous system
A
generally briefer
11
Q
duration of action in endocrine system
A
generally longer
12
Q
exocrine glands
A
secrete their products into ducts to be excreted to external environment
13
Q
endocrine glands
A
do not have ducts, secret hormones
14
Q
receptors are constantly being _____ and ______
A
synthesized and broken down
15
Q
down regulation makes cells
A
less receptive
16
Q
up-regulation makes cells more receptive
A
16
Q
up-regulation makes cells more receptive
A
17
Q
lipid soluble hormones
A
steroid hormones, thyroid hormones, nitric oxide
18
Q
water soluble hormones
A
amine hormones, peptide hormones, eicosanoid hormones
19
Q
steriod hormones
A
derived from cholesterol
20
Q
thyroid hormones
A
although a protein, they behave like a lipid
21
Q
nitric acid
A
gas produced by endothelial cells
22
Q
amine hormones
A
decarboxylation of selected Amino Acids
23
Q
peptide hormones
A
small to large proteins
24
eicosanoid hormones
- fatty acids that behave like proteins
- classified as autocrine/paracrine hormones
25
most water-soluble (hydrophilic) hormones circulate in _________
free form
26
what does preprohormone and prohormone refer to
inactive precursors
27
how often are peptide hormones release
- released in burst frequently throughout day.
28
mechanism of lipid-soluble hormones
- diffuse through the cell membrane
- bind to receptors in the cytosol or nucleus
29
cytoplasmic and nuclear receptors lead to what types of response
genomic response - which activate and represses gene transaction
30
thyroid hormones
- behaves like steroid hormone
31
T3 and T4 transported in blood by
- thyroid-binding globulin (TBG)
- transthyretin
- albumin
32
which hormones cannot cross the plasma membrane, so they must bind to the surface membrane receptors
- amine, peptide, protein
33
g- protein once activated will....
- open an ion channel in the membrane
- turns on amplifier enzyme
34
______ converts ATP into cyclic AMP
Adenylyl cyclase
35
2nd messenger and function
Cyclic AMP
- alter ion channels
- activated protein kinase A
36
1st messenger and function
hormone
- binds to surface cell receptors
37
amplifier enzyme is most common in
G-protein
38
synergistic effect
something is better when combined than each individual item
39
permissive effect
hormone cannot fully work without the permission from another hormone
40
antagonist effect
one hormone opposing the action of another hormone
41
humoral stimuli
changes in composition of extracellular fluid
ex) rise in blood glucose levels triggers the pancreatic release of insulin
42
hormonal stimuli
release of a hormone in response to another hormone
43
neural stimuli
stimulates endocrine glands to release hormones
44
simple endocrine reflex
cell senses a change in environment and then secrets a hormone in response
45
complex neuroendocrine reflexes
- involves two or more hormones
-one organ typically releases hormones that control the release of additional hormones from another part of the body
46
2 major groups of neurohormones
- catecholamines
hypothalamic neurohormones
47
neurohypophysis stores and releases what
- antidiuretic hormone ADH
- oxytocin
48
antidiuretic hormone ADH
-promotes H2O conservation by kidneys
- elevates BP
- contraction of blood vessels
49
oxytocin
- stimulates contractions of uterus during parturition
- ejection of milk during breast feeding
50
pars intermedia secrets _______ (MSH)
Melanocyte-Stimulating Hormone
51
increase in production of melanin helps with....
- provides pigmentation to hair, eyes and skin
52
when is MSH produced
- mainly during fetal development
53
adenohypophysis
produces and secrets majority of the hormones of pituitary gland
54
function of IGF and growth hormone
- increase growth of muscle, bone and soft tissue
- decreases protein breakdown
- enhances lipolysis and decrease glucose uptake
55
hormones that use short look negative feeback
- ACTH
- prolactin
- growth hormone
56
what is hypersecretion
- excess hormone
- caused by exogenous administration or tumors
- too much hormone is secreted
57
prolonged exogenous exposure may cause?
glands to shrink, lose ability to regain normal function when exogenous use stops
58
hyposecretion
- amount of hormones that is released is to low
- caused by decreased trophic hormone synthesis or atrophy of a gland
59
primary hypersecretion
problem occurs at adrenal gland
60
secondary hypersecretion
problem occurs with the enzyme
61
tertiary hypersecretion
problem occurs at the hypothalamus
62
primary hyposecretion
something wrong with adrenal gland
63
secondary hyposecretion
something wrong with the pituitary gland
64
tertiary hyposecretion
something wrong wtih hypothalmus
65
cortex secretes ______
steroid hormones called corticosteroids
66
different classes of hormones in cortex
mineralocorticoids, glucocorticoids, androgens
67
mineralocorticoids
regulate mineral homeostasis
68
glucocorticoids
affect glucose homeostasis
69
androgens
produce weak masculinizing effects
70
medulla secrets ____?
neurohormones
71
subgroups of mineralocorticoids
aldosterone and desoxycorticosterone
72
aldostrone secretion controlled by (in order)
- blood K+ levels
- Renin
- blood Na+ levels
- ACTH
73
what is renin
hormone produced by kidneys
74
action of aldostrone
- renal extraction of K+ and H+
- reabsorbs Na+ and water to maintain blood pressure and blood volume
75
subgroups of glucocorticoids
- cortisol
- corticosterone
- cortisone
76
action of cortisol
- gluconeogenesis in liver
- causes breakdown of skeletal muscle proteins
- enhances lipolysis
- suppress immune system
- causes negative Ca+ balance
- influences brain function
77
how much epinephrine and norepinephrine does the medulla secret
80% epinephrine
20% norepinephrine
78
eustress
- positive stress
79
distress
- negative stress
80
what is hypercortisolism
when body produces too much cortisol
81
cause of hypercortisolism
adrenal or pituitary tumors
82
what does hypercortisolism lead to
- hyperglycemia (mimics diabetes)
- muscle breakdown (tissue wasting)
- redistribution of body fat
