Lecture 13-14 VNS

Question 1

source and target for info for somatic vs visceral NS

Answer 1

somatic: sensory info from outside world. target= skeletal muscle

visceral” sensory info from viscera. target= smooth muscle, cardiac muscle, glandular tissue

Question 2

what is the motor divisions of visceral ns

Answer 2

parasympathetic and sympathetic ***note these are NOT sensory

Question 3

label top and bottom

Answer 3

top= somatic

bottom = autonomic

Question 4

how many neurons btw CNS and target in somatic NS? visceral?

Answer 4

somatic: one neuron from CNS to target

Visceral: primary neuron from CNS synapse with secondary in gangion outside CNS. then target

Question 5

what is autonomic NS?
what’s it divided into?

Answer 5

motor subdivision of VNS

divided into Sympathetic and PSNS

Question 6

where are parasympathetic primary neurons found? synapse??

Answer 6

brainstem and S2-S4 of lateral horn

synapse with visceral ganglia which are very near to target

Question 7

where are sympathetic primary neurons found? where do they synapse

Answer 7

T1-L2 lateral horn

synapse either are para-vertebral OR pre-vertebral ganglia

Question 8

examples of somatic plexi?

Answer 8

cervical, bracial, lumbar, sacral

Question 9

what is the motor component of VNS always associated with?

Answer 9

ganglion

motor componeny = ANS

Question 10

label the three ganglia

Answer 10

1. Paravertebral Ganglia (Sym.)
2. Visceral Ganglia (PSNS)
3. Pre-Vertebral Ganglia (Sym.)

Question 11

label the three regions, are they parasympathetic or sympathetic?

Answer 11

top= Brainstem. PSNS.

mid: T1-L2 of lateral horn of spinal cord (SYMP)

bottom: S2-S4 of lateral horn. PSNS

Question 12

which autonomic nerve fibres arise from brainstem? where do they travel to?

Answer 12

4 pairs of primary parasympathetic neurosn form nucleus in brainstem. axons join to nerves which arise from brainstem (CN III, VII, IX, X). reach target and synapse with secondary neuron VERY CLOSE TO TARGET in visceral ganglia

Question 13

which neurons arise from T1-L2 of lateral horn? where do it travel

Answer 13

sympathetic preganglionic (primary). synapse either at para-vertebral OR pre-vertebral ganglia with secondary (postganglionic) sympathetic neuron.

Question 14

which neurons arise from S2-S4? where do they travel

Answer 14

PSNS primary preganglionic fibres. Reach visceral ganglion and synapse with secondary postganglionic neuron.

Question 15

where is prevertebral ganglia found?

Answer 15

only found in abdominal cavity (lumbar). primary axons which bypass the paravertebral ganglia synapse here

Question 16

what are fibres that synapse with prevertebral ganglia called (sympathetic)

Answer 16

splanchnic nerve

Question 17

what is the white ramus communicans

Answer 17

nerve bundle bridge btw spinal nerve and paravertebral ganglia. preganglionic sympathetic fibres travel through

Question 18

what is gray ramus communicans

Answer 18

second bridge in sympathetic pathway. post ganglionic fibre travel through after synapsing with primary. get back to spinal nerve

Question 19

what fibres do ventral root carry

Answer 19

motor! so sympathetic fibres.

Question 20

which sympathetic fibres supply head, neck, upper limbs

Answer 20

those arising from T1

Question 21

which sympathetic fibres reach thoracic viscera?

Answer 21

thoes arising from t1-t4

Question 22

how do neurons from T1 reach hea?

Answer 22

use sympathetic trunk as ladder to get up