Flashcards in Spinal Nerves and the Spinal Cord Deck (29)
What makes up the entire PNS?
What is an endoneurium?
Loose, connective tissue surrounding a single axon, insulating and keeping info within that one axon
What is a bundle of axons collected in one group in a nerve called?
Which connective tissue layer wraps around a fascicle?
Which connective tissue layer surround the outside of the entire nerve?
If a nerve, an area of axons, is known as a 'nerve' in the Peripheral Nervous System, what is it known as in the Central Nervous System?
Tract, or white matter
If ganglia, a structure containing nerve cell bodies, is known as 'ganglia' in the Peripheral Nervous System, what is it known as in the Central Nervous System?
Nuclei or grey matter
Can axons be regenerated in the PNS?
It is possible but does not always. It tries to repair axons.
Can axons be regenerated in the CNS?
No, because there is no mechanism in it to do so
During the regeneration of an axon in the PNS, which side of the damaged nerve is more active in guiding the process of regeneration?
The side that is distal or attached to the muscle.
During the regeneration of axon in the PNS, what is the role of the neurolymmocytes?
From the distal side, the neurolymmocytes divide and spread back to the proximal side. They form a channel to guid the original axon back to the effector organ.
What causes the atrophy of a muscle?
If the axon is too far away from the neurolymmocytes trying to form a channel back to the axon.
3 Functions of the Spinal Cord:
1) Convey sensory information from the PNS to the brain
2) Convey motor information from the brain to the PNS
3) Processes sensory information but in a limited manner
Where is the spinal cord located in the spine?
In the vertebral column of the backbone.
How many pairs of spinal nerves are there?
What are the bundle of spinal nerves that extend beyond the spinal cord?
Where does the spinal cord end?
Between L3 and L4.
What are the spinal nerves grouped and categorized under?
Plexi (Singular: Plexus)
Where is the cerebrospinal fluid located?
In the central canal of the spinal cord
What is the role of the white matter in the spinal cord in reference to the brain?
It brings information to and from the brain.
What is in the dorsal root ganglion?
Sensory cell bodies. It is responsible for info coming into the spinal cord.
True or False: Spinal NERVES are mixed nerves, so info can travel right and left in the spinal cord.
Which root does information come INTO the spinal cord, and why?
The Dorsal Root, and because of the Dorsal Root Ganglion which is sensory.
5 components of a Spinal Reflux:
1) Sensory Receptor
2) Sensory Neuron
3) Association Neuron (although sometimes a reflux will skip the interneuron and go straight to the motor neuron)
4) Motorneuron (passes onto the spinal nerve)
5) effector organ
Is the brain involved in the reflux process?
3 Major Types of Spinal Reflexes:
1) Monosynaptic Reflex
2) Polysynaptic Reflex
3) Complex Reflex
Determined by the number of synapses between the sensory and motor neurons.
Two neurons involved, but one synapse.
Greater than two neurons are involved.