Lab 02: Anatomy of the Peripheral Nervous System

1

Suprascapular Nerve (C6)

2

Axillary Nerve (C7)

3

1st Subscapular Nerve

4

2nd Subscapular Nerve

5

Musculocutaneous Nerve

6

Radial Nerve (C8)

7

Median Nerve

8

Ulnar Nerve

9

1st Thoracic Nerve

10

Ventral Thoracic Nerve

11

Long Thoracic Nerve

12

3rd Subscapular Nerve

13

Phrenic Nerve

14

Vagus Nerve (C10)

Suprascapular Nerve (C6)

1

Cervical Nerve 5

2

Cervical Nerve 4

3

1st Subscapuar Nerve

4

2nd Subscapular Nerve

5

Axillary Nerve (C7)

6

Musculocutaneous Nerve

7

Radial Nerve (C8)

8

Medial Nerve

9

Ulnar Nerve

10

1

Cervical Nerve 1

2

Cervical Nerve 2

3

Cervical Nerve 3

4

Cervical Nerve 4

5

Cervical Nerve 5

6

Cervical Nerve 6 (Subscapular Nerve)

7

Vagus Nerve (10)

8

Spinal Accessory Nerve

Peripheral Nervous System (PNS)

consists of a sensory & motor division; components are the receptors, nerves, ganglia, & plexuses; responsible for detecting stimuli in & around the body, conducting action potentials to the Central Nervous System for interpretation

Sensory Division

transmits electrical signals from specialized receptor in the body towards the CNS (aka afferent division)

Motor Division

transmits electrical signals from the CNS to the effector organs (aka efferent division)

Somatic

Voluntary

Autonomic

Involuntary

Dendrites

recieve information from other neurons or from sensory receptors

Neuron cell body

contains nucleus & other organelles, processes information

Axon

central processes of neuron that conducts action potential away from the cell body

Schwann Cell

form myelin sheath

Nodes of Ranvier

gaps in myelin sheath that aid in signal conduction

Spinal Accessory n. XI (motor)

sternocleidomastoid & trapezius muscles

Hypoglossal n. XII (motor)

muscles of the tongue

Vagus n. X (both motor & sensory)

both motor & sensory fibers to visceral body organs

Infraorbital n.

lower eyelid & upper lip; infraorbital canal

Phrenic n.

diaphragm muscles to control breathing; both nerves run from C3-C5 along the anterior scalene muscles before dividing into the thorax to pass between the lungs & heart

Suprascapuar n.

supraspinatus & infraspinatus muscles; suprascapular notch of the scapula

Subscapular n.

subscapularis, teres major, & latissimus dorsi muscles

Axillary n.

detoid & teres minor muscles

Musculocutaneous n.

coracobrachialis, biceps brachii, & brachialis muscles

Radial n.

triceps brachii & all muscles of the posterior forearm, sensation to lateral posterior surface of the hand; radial groove of the humerus bone

Median n.

sensation to the later anterior hand

Ulnar n.

sensation to the anterior & posterior medial hand; behind the medial epicondyle of the humerus

Long thoracic n.

Serratus anterior muscle

Sciatic n.

biceps femoris, semitendinosus & semimembranosus muscles; greater sciatic notch of the pelvis

Tibial n.

gastrocnemius, soleus & plantaris muscles

Common fibular nerve

anterior muscles of the leg (not the thigh)

Femoral n.

rectus femoris, vastus medialis, vastus lateralis, & vastus intermedius

Lateral cutaneous n.

sensation to the lateral thigh

Obturator n.

sensation to the medial thigh; obturator foramen of the hip

Saphenous n.

sensation to the medial leg & medial ankle/foot

Sympathetic trunk & ganglia

distributes fibers through the ramus communicans for sympathetic influence into spinal nerves

Vagus nerve pathology

clinical malfunctions may include dysphagia, vocal cord weakness & alterations of the parasympathetic tone of the thorax & abdomen

radial nerve pathology

when damaged, an individual cannot draw their wrist up & thus this condition is referred to as wrist drop

Median nerve pathology

carpal tunnel syndrome is generally associated with compression of this nerve

ulnar nerve pathology

superficial & thus often exposed contact stimulation & pain in the funny bone

long thoracic nerve pathology

when this nerve is damaged, the scapula wings out as it can no longer be held against the body wall

common fibular nerve pathology

when damaged, muscles in the posterior leg are no longer antagonized by contracting muscles from the anterior leg resulting in an unsynchronized foot drop with each step