Chapter 21 Flashcards
(41 cards)
How are nerves named?
- named according to the level of the vertebral column at which they emerge
- the vertebra
Where do the nerves exit in relation to the associated vertebra?
- the cervical nerves exit above the vertebra they are named after
- the rest of the nerves exit underneath the vertebra they are named after
How many of each nerve are there?
- Cervical: 8 pairs
- Thoracic: 12 pairs
- Lumbar: 5 pairs
- Sacral: 5 pairs
- Coccygeal: 1 pair
How is a spinal nerve formed?
-the anterior root and posterior root join together
Is the anterior root motor or sensory?
-motor
Is the posterior root motor or sensory? What is something special that it contains?
- sensory
- dorsal root ganglion
What are the branches that come off the spinal nerve?
- anterior ramus
- posterior ramus
- meningeal ramus
- rami communicante
Where does the anterior ramus innervate?
- muscles and glands in the upper and lower limbs
- lateral and anterior portions of the neck and trunk
Where does the posterior ramus innervate?
-the skin and some deep muscles of the posterior head, neck, and trunk
What does the rami communicante do?
-joins the nerve to the sympathetic chain
What is a plexus?
-the braiding of the nerves which causes multiple nerves to go to one location
What are the pros of the plexuses?
-if damage happens to one nerve then the others can still allow the location to function
What are the plexuses made of?
-anterior rami
What are the different plexuses?
- cervical plexus
- brachial plexus
- lumbar plexus
- sacral plexus
What is the progression of the brachial plexus?
-roots-> trunks-> divisions-> cords-> nerves
What anterior rami make up each plexus?
- Cervical: C1-C5
- Brachial: C5-T1
- Lumbar: L1-L4
- Sacral: L4-S4
What important nerves come off the cervical plexus? Function?
- Phrenic nerve
- C3,4,5 keep the diaphragm alive
What important nerves come off the bracial plexus? Function?
- axillary nerve: shoulder
- radial nerve: posterior arm and forearm
- musculocutaneous nerve: anterior arm
- median nerve: anterior forearm, part of hand
- ulnar nerve: anterior forearm and part of hand
What important nerves come off the lumbar plexus? Function?
- femoral nerve: motor: muscles of anterior thigh; sensory: anterior thigh and medial side of leg
- obturator nerve: motor: adductors of thigh
What important nerves come off the sacral plexus? Function?
- sciatic nerve: motor: posterior thigh, entire leg, and entire food; sensory: everything that the femoral doesn’t cover
- pudendal nerve: anus
What is erb-duchenne palsy?
- waiter’s tip
- loss of sensation along the lateral side of the arm
- injury to the C5-C6
What is wrist drop?
- the inability to extend the wrist and fingers
- injury to radial nerve
What is a dermatome? How does it relate to shingles?
- the skin surface area supplied by sensory fibers of a given spinal nerve
- shingles affects one dermatome
What is a myotome?
-skeletal muscle or group of muscles that receives motor axons from a given spinal nerve
