PNS & ANS (W3) Flashcards
What its the PNS
outside the CNS
- receives information and gives info to CNS
What are the
- dorsal
- ventral root
Dorsal - sensory input
Ventral - motor output
What is the purpose of the ganglion
bundle of cell bodies transmitting sensory information
What is the weakest point in you spine
intervertebral foramina
What is the ventral horn
where motor nuerons have their cell bodies
- towards bottom of grey matter
How many spinal nerves do we have
31 pairs
Name the spinal nerves
- 8 cervial
-12 thoracic - 5 lumbar
- 5 sacral
- 1cocygeal
What are the peripheral nerve and where do they arise form
mix of motor and sensory neurons and arise from spinal nerves
Where do the peripheral nerve originate
brian and spinal cord
What is the ventral rami
(nerve plexus)
supply the limbs via the interwoven network of fibres
What is a communicating ramus
further branches of spinal nerves
- connect sympathetic chain
- occur at spinal level T1-L3
What is a dermatome
area of skin innervated by sensory axons of a single dorsal nerve root
What are nerve coverings
continuum of the the meninges
Describe the layers of the nerve coverings
Epineurium - continuum of there dura mater & provides mechanical strength for the nerve
Perineurium -
Endonerurium - continuum of the arachnid matter
What are Schwann cells (oligodendrocytes)
- supportive glial cells in nerves
- regulate the axons keeping the environment the same
What determines how quickly the information travels
- width (wider = faster, more myelin)
What is signal transduction in a sensory component
process of converting the energy of a stimulus into an electrical signal
What ending is responsible for signal transduction
somatosensory by opening of cation channel producing a depolarising receptors potential
What is a receptive field
area of skin inverted by a single sensory afferent
What is 2 point discrimination
measures the minimum inter-stimulus distance required to perceive 2 stimuli and different point
What is visceral sensory information
What does the dorsal root ganglia do in visceral sensory information
tends visceral afferent through sympathetic nerves
What are proprioceptors
muscle, tendons and joint mechanoreceptors
