Chapter 13 Flashcards
Spinal cord
housed with protective membranes (meninges) and vertebral column.
There is more gray matter at the cervical level. Why is this?
Having a mass to hold the brain.
Connects to the trunk and limbs.
Sending msgs everywhere.
Cauda means, equina means
Tail- opposite of head, horse3
Peripheral nervous system
Cranial nerves + spinal nerves
sensory input and motor response pathways
Order of meninges from most superior to most inferior?
Dura mater > Arachnoid mater > Pia mater (DAP)
C8 is ___ seventh cervical vertebra
below
Main function of the spinal meninges
protect and support the spinal cord.
White matter is made up of what
myelinated and unmyelinated axons
Gray matter is made up of
cell bodies of neurons, neuroglia, and unmyelinated axons
Three connective tissue layers surround spinal nerves (EPE)
Epineurium > perineurium > endometrium
Dermatomes:
specific bilateral region of skin supplied by a single pair of spinal nerves
Sensory information for T1>L2
- The sympathetic nerve carries sensory information from the visceral organs
- The anterior ramus carries sensory information from the ventrolateral body surface, structures in the body wall, and the limbs.
- The posterior ramus carries sensory information from the skin and skeletal muscles of the back
- The posterior root of each spinal nerve carries sensory information to the spinal cord.
Sympathetic nerve > anterior ramus > posterior ramus > posterior root of each spinal nerve to spinal cord.
Motor information from T1-L2
Anterior root of each spinal nerve > posterior root > posterior ramus > anterior ramus > white ramus > gray ramus > sympathetic nerve to thoracic cavity.
If the anterior ramus of a spinal nerve were cut, what would be the result in the tissue or region that nerve supplies?
loss of voluntary movement
A viral disease that destroys the cells of the anterior gray horn will
lead to skeletal muscle weakness or paralysis.
Development Reflexes:
Innate: Genetically determined
Acquired: Learned
Response Reflex
Somatic reflex: skeletal muscle contractions
Visceral reflex: control actions of smooth and cardiac muscles, and glands
Complexity of Circuit
Monosynaptic: one synapse or two synapses (neurons)
Polysynaptic: multiple synapses (more than 2 neurons)
Processing site
Spinal reflex: in spinal cord
Cranial reflex: in the brain
Events in a reflex arc:
Arrival of stimulus > activation of sensory neuron > > processing in CNS > activation of motor neuron > response by a peripheral effector
If one rami at one section is cut
info can still be received by the other root, but info is diminished a little bit.
4 major nerve plexus
cervical, brachial, lumbar, sacral
anterior gray horn controls
motor movement
posterior gray horn controls
sensory
