Spinal Nerves

Question 1

Brachial plexus

Answer 1

Innervation of pectoral girdle
C5-T1

Every trunk branches to form a cord.

1) superior trunk = C5 and C6
2) middle trunk = C7
3) inferior trunk = C8 and T1

4) lateral cord = superior and middle trunk
5) posterior cord = superior, middle, and inferior trunk
6) medial cord = inferior trunk

7) radial nerve = posterior cord
8) axillary nerve = posterior cord
9) musculocutaneous nerve = lateral cord
10) median nerve = lateral and medial cord
11) ulnar nerve = medial cord

Question 2

Lumbar Plexus
Sacral plexus

Lumbosacral

Answer 2

Sacral plexus :

1) sciatic nerve = L4-S3
2) pudenda nerve becomes fibular nerve

Lumbar plexus :

1) genitofemoral nerve
2) lateral femoral cutaneous nerve
3) femoral nerve

Sciatic nerve branches to
- tibial nerve & common fibular nerve

Common fibular nerve branches to
- deep & superficial fibular nerve

Question 3

Reflex Arc

Answer 3

1) arrival of stimulus and activation of receptor
2) activation of sensory neuron
3) information processing in CNS
4) activation of a motor neuron
5) response by effector

Question 4

Monosynaptic reflex

Answer 4

One motor neuron stimulation

Question 5

Polysynaptic reflex

Answer 5

Interneurons stimulation
👇🏻
Connect to several motor neurons

Question 6

Stretch reflex

Answer 6

Monosynaptic
Automatic response

Patellar reflex is controlled by muscle spindles in the quads. The stimulus is a reflex hammer striking the muscle tendon, stretching the spindle fibers

Check damage for L2-L4

Question 7

Cervical plexus

Answer 7

Groups of nerves located in cervical area. C1 - C5
Cutaneous and muscular

Phrenic nerve - innervates to diaphragm