Unit 2 lab Flashcards
Nerve plexuses
Branching/ intersecting nerve fibers that deal w/ (mostly) voluntary/ somatic sensation and movement
Where do nerve plexuses come from?
Spinal nerves
Spinal nerves
Separate into smaller branches (rami)
- dorsal ramus
-Ventral ramus
- rami communications
- meningeal branch
Dorsal ramus (spinal nerves)
Goes to targets in dorsal (back) areas, to supply areas in that region
Ventral ramus (spinal nerves)
Goes to targets n the ventral (front) areas; in thoracic regions, become intercostal nerves
Rami communicates ( spinal nerves)
Go to ANS in thoracic regions (do not merge into plexi)
Meningeal Branch (spinal nerves)
Loops to vertebra area, to meninges, n some regions
In thoracic region the ventral rami___
(Spinal nerves)
Do not make plexi
In rest of regions, what does ventral rami make?
(Spinal nerves)
Make plexi
What does plexi form from? (Nerve plexus)
Form from the ventral/ anterior rami of spinal nerves (no dorsal rami)
Purpose of nerve plexus
Different spinal nerves are sorted and recombined, so all fibers going to a specific body part are put together in one nerve
Advantage of nerve plexus
If there is damage to one spinal nerve, it does not eliminate all functions in one limb
How many plexi originating from spinal cord?
Multiple plexi
Most spinal nerves converge into a plexi, except___
Except spinal nerves T2- T11
What are T2-T11?
Intercostal nerves and do not converge because each nerve projects along one rib
Is there sharing of branches of spinal nerves?
Some sharing between plexi
Most afferent and efferent fibers in the plexus deal w/?
Voluntary functions but there are few exceptions
What does cervical plexus supply?
Supply skin in upper regions and control diaphragm
What discs makeup cervical plexus ?
C1-C4 (small contribution of C5 )
C1-C4(C5) supply?
(Cervical plexes)
Supply sensory fibers to the skin of neck, ears, head, shoulders, one big exception
Exception of cervical plexus?
Phrenic nerve
Phrenic nerve (cervical plexus)
Supplies motor and sensory fibers to the diaphragm, the chief breathing muscle
What discs keep diaphragm alive?
C3, C4,C5