Lec 9 Flashcards
What are the types of sensory info available (7)
proprioception
superficial touch
deep touch
vibration
pain
temperature
itch?
What are spinal dermatomes
areas of skin innervated by a single spinal segment.
Creates a segmented map of sensory distribution across body
innervation for face = trigeminal nerve (CN V)
what are the spinal dermatome regions?
and roughly what areas they innervate?
where does the innervation from the face come from?
Cervical - back of head to upper back and top of arm including index and middle finger
thoracic - lower arm and torso
lumbar - lumbar region, top of feet, and front of leg
sacral - lateral three toes, bottom of foot, back of legs, bottom, genitals
Coccygeal - one small area of anus
innervation for face = trigeminal nerve (CN V)
C5 dermatome, innervation
lateral delt and lateral upper arm
C6
lateral part of forearm + index + thumb
C7
hand and middle finger
C8
hand and ring/pinky finger
T4
Cross through nipple line and just above (front and back)
T10
Go through belly button and a little above (front and back)
L2
thigh (but not knee), low back, lateral thigh (not hamstrings)
L3
Knee
L4
medial lower leg
L5
Lateral/anterior lower leg (but not part where achilles is)
S1
achilles and bottom of foot (but not big toe), lateral two toes/slightly top of foot
Two main sensory ascending pathways
Posterior column-medial lemniscus pathway (PCMC)
- Vibration, proprioception, light touch
Antero-lateral pathway
- Pain, temp, crude touch,
What is crude touch
allow you to tell something is touching your skin but can’t tell what/not have more detailed info
Which pathway does vibration, what else does it do/info or details about it
Posterior column-medial lemniscus pathway (PCML)
- Vibration
- proprio
- light touch
- large afferent fibres
which pathway does Pain, what else it do and any other info
Antero-lateral pathway
- Pain
- temp
- crude touch
- smaller diameter
What are the pathways for upper and lower body in the PCML pathway (2) and where they synapse to.
at what point in the spinal cord does the PCML pathway travel in each
Fasciculus Gracilis -> Nucleus Gracilis
- Lower body primary sensory neurons travel here
Fasciculus Cuneatus -> Nucleus Cuneatus
- Upper body primary sensory neurons travel here
above T6, travel in cuneatus, below, travel in gracilis
where does the PCML pathway decussate?
Caudal medulla
Difference between first, second and third order neurons
First order - directly receive info from periphery
Second order - receives from first order and transmits it up the spinal cord
Third, from thalamus to cortex
describe the path of the PCML path from origin in spinal cord to finish
- enter dorsal root ganglion
- travel up to caudal medulla then decussate
- through pons, and midbrain to ventral Posterior Lateral Nucleus of the Medulla
- up to the associated area of the somatosensory cortex.
define the term bifurcate
single neuron splits into two branches
