Lecture 11 9/26/23 Flashcards
What are the characteristics of the CNS?
-surrounded by bone
-includes brain and spinal cord
What are the characteristics of the PNS?
-includes cranial and spinal nerves
-12 pairs of cranial nerves
-35 pairs of spinal nerves
What is the spinal nerve formula?
-C8T13L7S3Cd4-5
What are the characteristics of efferent fibers?
-away from CNS
-motor fibers
What are the characteristics of afferent fibers?
-towards CNS
-sensory fibers
What are the types of neurons?
-multipolar; efferent; motor
-bipolar; afferent; sensory
-pseudounipolar; afferent; sensory
What are the types of efferent fibers?
-general somatic efferent (GSE)
-general visceral efferent (GVE)
-special visceral efferent (SVE)
What are the characteristics of GSEs?
-motor to skeletal m.
-found in some cranial nerves and all spinal nerves
What are the types of afferent fibers?
-general somatic afferent (GSA)
-general visceral afferent (GVA)
-special somatic afferent (SSA)
-special visceral afferent (SVA)
What are the characteristics of GSAs?
-talk with GSEs
-receptors near body surface
-sense touch, temp., and pain
-some cranial nerves and all spinal nerves
What are the cauda equina?
nerves that must travel down to their exits; form a “horse tail”
What are intumescences?
swellings in the spinal cord where the limbs arise that account for the neuronal cell bodies that innervate the limbs
Where do the cervical nerves exit?
in front of the vertebrae with the same number
Where do the thoracic nerves exit?
behind the vertebrae with the same number
Where does cervical nerve 8 exit?
in front of T1/behind C7
Why must the caudal equina nerves run down to their exits?
the spinal cord ends short and does not reach the exits
What is the spinal nerve?
where the dorsal and ventral roots meet
Where is the dorsal root ganglion located?
within the dorsal root
Where does the dorsal branch go?
to the epaxial structures
Where does the ventral branch go?
to the hypaxial structures
Which type of neuron is in the dorsal root ganglia?
pseudounipolar (GSAs and GVAs)
Which type of fibers are found in the dorsal root?
sensory only
Which type of fibers are found in the ventral root?
motor only
Which types of fibers are found in the spinal nerve, dorsal branch, and ventral branch?
sensory and motor
