L23 - autonomic nervous system

Question 1

afferent neurones

Answer 1

sensory input from periphery to CNS

Question 2

efferent neurones

Answer 2

output from CNS to periphery (somatic or autonomic), causes skeletal muscles to move

Question 3

what does the ANS do?

Answer 3

provides input to tissue that’s not under voluntary control (smooth & cardiac muscle and glandular tissue)

Question 4

2 branches of ANS

Answer 4

sympathetic & parasympathetic
(have opposite actions but not equal)

Question 5

sympathetic nervous system

Answer 5

fight or flight

Question 6

parasympathetic

Answer 6

rest and digest

Question 7

somatic motor fibre

Answer 7

neurone that goes from spinal cord to skeletal muscle to enable us to have voluntary control of it (neurone releases ACh)

Question 8

ganglian

Answer 8

collection of cell bodies

Question 9

sympathetic branch of ANS has what type of ganglion?

Answer 9

short pre ganglion fibre and long post ganglionic fibre

Question 10

parasympathetic branch has what type of ganglion?

Answer 10

long pre ganglion fibre and short post ganglionic fibre

Question 11

what do the short pre ganglionic neurones tend to project to from the sympathetic nervous system?

Answer 11

paravertebral sympathetic chain

Question 12

what do the long post ganglionic neurones in the sympathetic nervous system send?

Answer 12

long axonal projections where the synapse ends on the target organ

Question 13

where does output from CNS from parasympathetic ns come to?

Answer 13

cranial nerves

Question 14

sympathetic division of ANS

Answer 14

• fight or flight mode
• sensors perceive you are in dangerous situation, tell the brain
• pupils dilate: better peripheral vision, see out corner of eye better
• inhibition of saliva and tears: saliva is part of digestion to not use up energy
• oxygenated blood sent to skeletal muscle
• airways dilate, relax airways in lungs so we can breath deeper
• accelerated heartbeat pumps blood around body faster
• liver stores glycogen which is metabolised into glucose (liver can still produce glucose without glycogen)
• intestines shut down
• bladder relaxes so can store more urine

Question 15

parasympathetic divison

Answer 15

• comes from vagus nerve
• constriction of pupil
• stimulation of saliva to digest food for nutrients
• lungs constrict, no more heavy energy demands
• stimulation of pancreas (insulin, enzymes etc)
• heart slows
• activation of rectum and bladder to use toilet

Question 16

vagus nerve

Answer 16

provides output from brain to periphery to parasympathetic

Question 17

is chemical or electrical signal responsible for slowing heart down?

Answer 17

chemical (ACh is released from vagus nerve)

Question 18

somatic efferents NT and receptors in ANS

Answer 18

ACh acts on nicotinic receptors to stimulate skeletal muscle

Question 19

sympathetic NT and receptors in ANS

Answer 19

ACh acts on nicotinic receptors on post ganglionic, post ganglionic neurone releases noradrenaline which activates adrenergic receptors on heart, blood vessels

Question 20

parasympathetic NT and receptors in ANS

Answer 20

ACh acts on nicotinic receptors on post ganglionic, post ganglionic neurone releases ACH to act on muscarinin receptors on heart, smooth muscle, sweat glands

Question 21

adrenal medulla exception for sympathetic NT and receptors

Answer 21

• one big long axon
• only produces ACh to act on adrenal medulla

Question 22

what does sympathetic input do?

Answer 22

• increase heart rate
• dilate pupils
  -relax airways

Question 23

what are adrenoreceptors?

Answer 23

receptors that respond to adrenaline

Question 24

muscarinic receptors

Answer 24

respond to ACh

Question 25

what type of of receptors are adrenoreceptors and muscarinin receptors?

Answer 25

g protein coupled receptors

Question 26

G protein coupled receptors

Answer 26

1. Gs-coupled: activates adenylate cyclase - leading to production of cAMP
2. Gi/Go-coupled: inhibits adenylate cyclase, and affects ion channels
3. Gq-coupled: activated phospholipase C - leading to production of IP3