Nerve plexus and branches

Question 1

What is the basic structure of peripheral nerves?

Answer 1

Axon -> Myelin sheath (schwann cells) -> Endoneurium -> Perineurium (blood vessels found within) = fasicle -> epineurium

Question 2

How to tendons looks on the human body?

Answer 2

Tight, white, bright structures

Question 3

How do you tell the difference between nerves and blood vessels?

Answer 3

In nerves, you can see the fasicle bundles. Arteries will also stay open due to elastic walls.

Question 4

What does myelination in the PNS?

Answer 4

• Schwann cells

Question 5

What are unmyelinated sheaths encased in in the PNS?

Answer 5

Still encased by schwann cell but just a single cell membrane layer

Question 6

What is the flow of stimulus through the nervous system?

Answer 6

1. Sensory (stretch) receptor (stimulus on skin)
2. Sensory (afferemt) neuron
3. Integration center
4. Motor (efferent) neuron
5. Effector

Question 7

What are the 12 pairs of cranial nerves?

Answer 7

Olfactory
Optic
Occulomotor 
Trochlear
Trigeminal 
Abducens
Facial
Vestibulocochlear
Glossopharyngeal
Vagus
Accessory 
Hypoglossal

Question 8

Where do the spinal nerves come out?

Answer 8

In the foremena inferior to the vertebrae. The exception is a nerve that comes between the occipital bone and the atlas. Therefore 8 spinal nerves in the cervical region, but 7 vertebrae

Question 9

What are the three layers around the brain and spinal cord

Answer 9

Pia mater -> arachnoid mater -> dura mater

Question 10

Where do the dorsal rami supply?

Answer 10

The posterior of the head and neck

Question 11

Where do the central rami supply?

Answer 11

Supply the main component of the trunk and limbs

Question 12

What are dermatomes?

Answer 12

• The area of skin innervated by a single spinal nerve

Question 13

What are the nerve plexus of the body?

Answer 13

• Cervical (C1-C5)
• Brachial (C5-T1)
• Lumbar (T12-L4)
• Sacral (L4-S4)

Question 14

What is the cervical nerve we need to know?

Answer 14

The phrenic nerve

Question 15

Where does the phrenic nerve innervate?

Answer 15

The diaphragm

Question 16

What are the three nerves in the ‘M’ of the brachial plexus - lateral to medial and where do they innervate?

Answer 16

Musculo-cutaneous (anterior flexor muscles)
Median (anterior forearm muscle)
Ulnar (flexor carpi ulnaris, supples extrinsic muscles of hand)

Question 17

What nerves come from the posterior branch of the brachial plexus

Answer 17

Axillary (goes to armpit - deltoid, scapula)

Radial (extensor muscles)

Question 18

What are the two nerves off the lumbar plexus?

Answer 18

• Obturator nerve (adductor muscles of the middle compartment of the thigh)
• Femoral nerve (runs into anterior thigh; rectus femorus)

Question 19

What are the nerves of the sacral plexus

Answer 19

Sciatic nerve (connective tissue sheath) contains the tibial nerve and the fibular nerve

Question 20

Where does the tibial nerve innervate?

Answer 20

Hamstring mucles, plantar flexors