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Flashcards in Endo - Intro Deck (36):
1

endocrine characteristics

secreted by specialized endo cells into blood
travel long distances

2

neuro-endocrine characteristics

product of neuron
released into blood

3

neural characteristics

product of a neuron
secreted into synaptic spaces
travels short distances

4

paracrine characteristics

secreted into extracellular space
diffuse short distances

5

autocrine characteristics

hormone secreting cell same as receptor containing cell

6

hormones : effects

usually more than one effect -
due to different target cells
or changes to effect based on developmental stage

7

peptide/protein hormone characteristics

encoded by DNA
hydrophilic
receptors on cell surface
secondary messengers
can be stored
often circulate unbound

8

amine hormone characteristics

tyrosine derivatives
hydrophilic
receptors on cell surface
secondary messengers
*exception T3/T4

9

thyroid hormones characteristics not like amines

intracellular receptors

10

steroid hormone characteristics

llipophilic (non-polar)
receptors in cytosol or nucleus
derived from CHL w/ cyclopentano... ring (no DNA)
not stored
bound to specific globulin in blood
long 1/2 lives

11

cross talk

may happen among hormone families
diff hormones bind to the same receptor

12

preprohormone actions

preprohormones are translated, partially then arrested by signal recognition complex that binds to signal peptides
the complex releases when it binds to a docking protein on the ER --> translation completes
--> prohormone

13

prohormone actions

prohormone is cleaved into active hormone in golgi
or prohormone is secreted and converted to active in ECF

14

active hormone secretion

packaged into secretory vesicles in golgi
await signal as membrane bound granules
exocytosed into blood stream

15

peptide hormone Tx route

not orally (inactivated by acid in stomach or peptidases in intestines)
usually injected

16

groups of amine hormones

thyroid hormones
catecholamines

17

amine hormones from tyrosine

T3 = 2 tyrosine + 3 Is
T4 = 2 tyrosine + 4 Is
cats = modified tyrosines

18

catecholamine synthesis steps

tyrosine --> dopa --> dopamine --> NE --> E

19

catecholamine synthesis location

synthesis enzymes in cytosol
stored till secreted

20

types of steroid hormones

glucocorticoids
mineralcorticoids
vit D
androgens
estrogens
progestogens

21

steroid sythesis

many enzymatic steps (many disorders possible)
cells only have enzymes for specific steroid to be made

22

steroidogenic enzymes

1. side chain cleavage enzyme; desmolase
2. 17 alpha-hydroxylase
3. 21-hydroxylase
4. aromatase

23

steroid metabolism

metabolized by cytochrome P50 in liver
excreted in urine or bile
1/2 lives can be very long (esp synthetic)

24

route of steroid hormone Tx

can be given orally

25

eicosanoid characteristics

derived from fatty acids (usually arachadonic acid)
released by lipases
act locally - paracrine
only active a few seconds (rapidly metabolized)

26

regulation of endocrine activity (broad)

rate of production*
rate of delivery (ex. blood flow)
rate of degradation (liver) and elimination (kidney)

27

chronotropic control

endogenous neuronal rhythm
based on diff external things (light/dark, eating, temp)
vary in time frame
may be diff @ diff life stages

28

pacemaker of circadian rhythms

suprachiasmatic nucleus

29

importance of pulsatile hormone release

maintains secretion of necessary hormones
continuous would inhibit other things or block production (down regulation of receptors)

30

binding proteins and half life

binding delays metabolism
provides reservoir of hormones
greater affinity to bps --> greater half life

31

hormone receptor characteristics

specificity (only certain hormones)
affinity (changed by conformation, down with high hormone levels)
density (up or downregulation --> de/sensitization)

32

permissiveness

one hormone in adequate amounts necessary for full effect of other protein to happen

33

synergism

combined effect is greater than sum

34

antagonism

one hormone lessens another hormone's response

35

agonist

molecule binds to receptor
induces receptor to biological effect
(act like hormone - may be more or less potent)

36

antagonists

molecule binds to receptor
blocks agonist from binding
no biological effect occurs