Autonomic Nervous system

Question 1

Parts of central NS

Answer 1

brain

spinal cord

Question 2

Parts of peripheral NS

Answer 2

autonomic NS

somatic NS

Question 3

parts of somatic NS

Answer 3

sensory

motor

Question 4

Function of ANS

Answer 4

maintain HOMEOSTASIS (stable internal environment with varying external conditions)

Question 5

Pupillary light reflex is ____

Answer 5

unconscious, involuntary depends on amount of light entry

Question 6

Difference between ANS vs. somatic

voluntary?

Answer 6

ANS = involuntary

Somatic = voluntary

Question 7

Difference between ANS vs. somatic

Projections

Answer 7

ANS = diffuse projection

Somatic = specific projections

Question 8

Difference between ANS vs. somatic

Speed of action

Answer 8

ANS = slow action

Somatic = rapid action

Question 9

Difference between ANS vs. somatic

innervation

Answer 9

ANS = innerv smooth and cardiac muscle and gland cells

Somatic = innerv skeletal muscle

Question 10

Difference between ANS vs. somatic

synapses

Answer 10

ANS = disynaptic

Somatic = monosynaptic

Question 11

Inputs of ANS

Answer 11

input to pregnaglionic neurons

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

Question 12

output of ANS

Answer 12

organs

Question 13

Subdivisions of ANS

Answer 13

Sympathetic

Parasympathetic

Enteric (digestion)

Question 14

Difference between sympathetic vs. parasympathetic

Location of preganglionic neurons

Answer 14

symp = pregang in thoracic and lumbar cord

parasymp = pregang in brainstem and sacral cord

Question 15

Difference between sympathetic vs. parasympathetic

location of ganglia

Answer 15

symp = ganglia near spinal cord

parasymp = ganglia near target organ

Question 16

Difference between sympathetic vs. parasympathetic

ratios of pre to post ganglionic

Answer 16

symp = 1:10

parasymp = 1:3

Question 17

what is ganglion

Answer 17

cluster of cell bodies in peripheral NS

Question 18

Preganglionic neurotransmitter of ANS

Answer 18

acetylcholine

Question 19

postganglionic neurotransmitter of ANS

–> sympathetic

Answer 19

Norepinephrine and epinephrine

Question 20

postganglionic neurotransmitter of ANS

–> parasympathetic

Answer 20

acetylcholine

Question 21

receptors for ANS

Answer 21

1) Ach (nicotinic vs. muscarinic)

2) NE (alpha vs. beta adrenergic)

Question 22

nicotinic ACh receptor

Answer 22

ionotropic so NT binds and channel opens for downstream depol

Question 23

muscarinic ACh receptor

Answer 23

GPCR

Question 24

Adrenal medulla is functionally a ____

Answer 24

sympathetic ganglion

Question 25

adrenal medulla innervation

Answer 25

preganglionic sympathetic neurons

Question 26

what does adrenal medulla release

Answer 26

norepinephrine and epinephrine into blood stream

Question 27

effects of adrenal medulla

Answer 27

widespread sympathomimetic effects (incr HR)

Question 28

How does ANS affect blood pressure?

Answer 28

Symp = via incr NE, incr BP Parasymp = via ACh, decr BP

Question 29

Sympathetic NS Effect on HR and Contractile force

Answer 29

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+

Question 30

Parasymp NS effect on HR and contractile force

Answer 30

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

Question 31

Atropine

Answer 31

Sympathomimetic M2 antagonist in heart --> incr HR

Question 32

Propanolol

Answer 32

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

Question 33

Baroreceptor reflex in response to low BP

Answer 33

incr sympathetic ouptut

Question 34

Baroreceptor reflex in response to high BP

Answer 34

increase in parasympathetic output

Question 35

Baroreceptor mechanism (primary mechanism)

Answer 35

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

Question 36

Baroreceptor 2nd mechanism

Answer 36

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

Question 37

Hypothalamus control release of ___

Answer 37

hormones via pituitary posterior pituitary: brain anterior pituitary: gland

Question 38

Effects of VASOPRESSIN on blood pressure

Answer 38

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

Question 39

Effects of RENIN

Answer 39

1) if low blood pressure detect 2) renin released from kidney 3) downstream activ angiotensin II (vasoconstrictor)

Question 40

Effects of angiotensin II

Answer 40

constrict blood vessel incr water retention in kidney activ neuron in subfornical organ