Lecture 13-14 VNS Flashcards
source and target for info for somatic vs visceral NS
somatic: sensory info from outside world. target= skeletal muscle
visceral” sensory info from viscera. target= smooth muscle, cardiac muscle, glandular tissue
what is the motor divisions of visceral ns
parasympathetic and sympathetic ***note these are NOT sensory
label top and bottom
top= somatic
bottom = autonomic
how many neurons btw CNS and target in somatic NS? visceral?
somatic: one neuron from CNS to target
Visceral: primary neuron from CNS synapse with secondary in gangion outside CNS. then target
what is autonomic NS?
what’s it divided into?
motor subdivision of VNS
divided into Sympathetic and PSNS
where are parasympathetic primary neurons found? synapse??
brainstem and S2-S4 of lateral horn
synapse with visceral ganglia which are very near to target
where are sympathetic primary neurons found? where do they synapse
T1-L2 lateral horn
synapse either are para-vertebral OR pre-vertebral ganglia
examples of somatic plexi?
cervical, bracial, lumbar, sacral
what is the motor component of VNS always associated with?
ganglion
motor componeny = ANS
label the three ganglia
- Paravertebral Ganglia (Sym.)
- Visceral Ganglia (PSNS)
- Pre-Vertebral Ganglia (Sym.)
label the three regions, are they parasympathetic or sympathetic?
top= Brainstem. PSNS.
mid: T1-L2 of lateral horn of spinal cord (SYMP)
bottom: S2-S4 of lateral horn. PSNS
which autonomic nerve fibres arise from brainstem? where do they travel to?
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
which neurons arise from T1-L2 of lateral horn? where do it travel
sympathetic preganglionic (primary). synapse either at para-vertebral OR pre-vertebral ganglia with secondary (postganglionic) sympathetic neuron.
which neurons arise from S2-S4? where do they travel
PSNS primary preganglionic fibres. Reach visceral ganglion and synapse with secondary postganglionic neuron.
where is prevertebral ganglia found?
only found in abdominal cavity (lumbar). primary axons which bypass the paravertebral ganglia synapse here
what are fibres that synapse with prevertebral ganglia called (sympathetic)
splanchnic nerve
what is the white ramus communicans
nerve bundle bridge btw spinal nerve and paravertebral ganglia. preganglionic sympathetic fibres travel through
what is gray ramus communicans
second bridge in sympathetic pathway. post ganglionic fibre travel through after synapsing with primary. get back to spinal nerve
what fibres do ventral root carry
motor! so sympathetic fibres.
which sympathetic fibres supply head, neck, upper limbs
those arising from T1
which sympathetic fibres reach thoracic viscera?
thoes arising from t1-t4
how do neurons from T1 reach hea?
use sympathetic trunk as ladder to get up
