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Flashcards in Autonomic Nervous system Deck (40)
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1

Parts of central NS

brain
spinal cord

2

Parts of peripheral NS

autonomic NS
somatic NS

3

parts of somatic NS

sensory
motor

4

Function of ANS

maintain HOMEOSTASIS (stable internal environment with varying external conditions)

5

Pupillary light reflex is ____

unconscious, involuntary depends on amount of light entry

6

Difference between ANS vs. somatic

voluntary?

ANS = involuntary

Somatic = voluntary

7

Difference between ANS vs. somatic

Projections

ANS = diffuse projection

Somatic = specific projections

8

Difference between ANS vs. somatic

Speed of action

ANS = slow action

Somatic = rapid action

9

Difference between ANS vs. somatic

innervation

ANS = innerv smooth and cardiac muscle and gland cells

Somatic = innerv skeletal muscle

10

Difference between ANS vs. somatic

# synapses

ANS = disynaptic

Somatic = monosynaptic

11

Inputs of ANS

input to pregnaglionic neurons
1) nucleus of solitary tract (medulla)
2) other brainstem nuclei (environ stim)
3) hypothalamus (internal state)

12

output of ANS

organs

13

Subdivisions of ANS

Sympathetic

Parasympathetic

Enteric (digestion)

14

Difference between sympathetic vs. parasympathetic

Location of preganglionic neurons

symp = pregang in thoracic and lumbar cord

parasymp = pregang in brainstem and sacral cord

15

Difference between sympathetic vs. parasympathetic

location of ganglia

symp = ganglia near spinal cord

parasymp = ganglia near target organ

16

Difference between sympathetic vs. parasympathetic

ratios of pre to post ganglionic

symp = 1:10

parasymp = 1:3

17

what is ganglion

cluster of cell bodies in peripheral NS

18

Preganglionic neurotransmitter of ANS

acetylcholine

19

postganglionic neurotransmitter of ANS
--> sympathetic

Norepinephrine and epinephrine

20

postganglionic neurotransmitter of ANS
--> parasympathetic

acetylcholine

21

receptors for ANS

1) Ach (nicotinic vs. muscarinic)

2) NE (alpha vs. beta adrenergic)

22

nicotinic ACh receptor

ionotropic so NT binds and channel opens for downstream depol

23

muscarinic ACh receptor

GPCR

24

Adrenal medulla is functionally a ____

sympathetic ganglion

25

adrenal medulla innervation

preganglionic sympathetic neurons

26

what does adrenal medulla release

norepinephrine and epinephrine into blood stream

27

effects of adrenal medulla

widespread sympathomimetic effects (incr HR)

28

How does ANS affect blood pressure?

Symp = via incr NE, incr BP

Parasymp = via ACh, decr BP

29

Sympathetic NS Effect on HR and Contractile force

SA node
1) NE binds Beta-adrenergic receptor

2) incr AC, cAMP

3) incr HR due to more HCN opening (cation entry) and depol quicker to incr firing rate

4) incr contractile force (more Ca2+ enters

5) constriction of blood vessels due to Ca2+

30

Parasymp NS effect on HR and contractile force

SA node
1) ACh binds m2 ACh receptors

2) activates G protein to inhibit AC, decr cAMP

3) decr HR = less HCN channel open

4) decr contractile force = less Ca2+ entry

31

Atropine

Sympathomimetic

M2 antagonist in heart --> incr HR

32

Propanolol

Parasympathomimetic

Beta adrenergic (1 and 2) antagonist in heart, decr HR

33

Baroreceptor reflex in response to low BP

incr sympathetic ouptut

34

Baroreceptor reflex in response to high BP

increase in parasympathetic output

35

Baroreceptor mechanism (primary mechanism)

1) Baroreceptor sense pressure at aortic arch

2) if incr blood pressure, activ nucleus of solitary tract in medulla to incr glu

3) incr glu release from nearby neurons

4) incr ACh release from cardiac plexus

5) ACh binds to nicotinic ACh receptor to cause more ACh release in SA node

6) decr HR and contractile force

36

Baroreceptor 2nd mechanism

1) neurons in solitary tract also activate nearby neurons to release GABA (inhib)

2) inhib release of Glu from neurons in T1-T5 in spinal cord

3) inhib ACh release from ganglia nearby

4) inhib NE release at SA node

37

Hypothalamus control release of ___

hormones via pituitary

posterior pituitary: brain
anterior pituitary: gland

38

Effects of VASOPRESSIN on blood pressure

1) if low blood pressure detect by subfornical organ

2) release vasopressin from posterior pituitary

3) causes vasoconstriction

4) act on kidney to incr water retention

39

Effects of RENIN

1) if low blood pressure detect

2) renin released from kidney

3) downstream activ angiotensin II (vasoconstrictor)

40

Effects of angiotensin II

constrict blood vessel

incr water retention in kidney

activ neuron in subfornical organ