BIOL 320 Lab 2 - Gross Anatomy of the Peripheral Nervous System

Innervation/Anatomical Pathways/Pathology

Spinal Accessory Nerve XI (motor)

Innervation/Anatomical Pathways — sternocleidomastoid and trapezius muscles

Hypoglossal Nerve XII (motor)

Innervation/Anatomical Pathways — muscles of the tongue

Vagus Nerve X (both motor and sensory)

Innervation/Anatomical Pathways — both motor and sensory fibers to the visceral body organs

Pathology — clinical manifestations may include dysphagia, vocal cord weakness and alterations of the parasympathetic tone of the thorax and abdomen

Infraorbital Nerve

Innervation/Anatomical Pathways — lower eyelid and upper lip; infraorbital canal

Phrenic Nerve

Innervation/Anatomical Pathways — diaphragm muscles to control breathing; both phrenic nerves run from C3-C5 along the anterior scalene muscle before diving into the thorax to pass between the lungs and heart

Suprascapular Nerve

Innervation/Anatomical Pathways — supraspinatus and infraspinatus muscles; suprascapular notch of the scapula

Subscapular Nerves

Innervation/Anatomical Pathways — subscapularis, teres major and latissimus dorsi muscles

Axillary Nerve

Innervation/Anatomical Pathways — deltoid and teres minor muscles

Musculocutaneous Nerve

Innervation/Anatomical Pathways — coracobrachialis, biceps brachii, and brachialis muscles

Radial Nerve

Innervation/Anatomical Pathways — triceps brachii and all muscles of the posterior forearm, sensation to lateral posterior surface of the hand; radial groove of humerus bone

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

Median Nerve

Innervation/Anatomical Pathways — sensation to the lateral anterior hand

Pathology — carpal tunnel syndrome is generally associated with compression of this nerve

Ulnar Nerve

Innervation/Anatomical Pathways — sensation to the anterior and posterior medial hand; behind the medial epicondyle of the humerus

Pathology — superficial and thus often exposed to contact stimulation and pain in the “funny bone”

Long Thoracic Nerve

Innervation/Anatomical Pathways — serratus anterior muscle

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

Sciatic Nerve

Innervation/Anatomical Pathways — biceps femoris, semitendinosus and semimembranosus muscles; greater sciatic notch of the pelvis

Tibial Nerve

Innervation/Anatomical Pathways — gastrocnemius, soleus and plantaris muscles

Common Fibular Nerve (gives off a superficial and deep branch and is also often cited as the common peroneal nerve)

Innervation/Anatomical Pathways — anterior muscles of the leg (not the thigh)

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

Femoral Nerve

Innervation/Anatomical Pathways — rectus femoris, vastus medialis, vastus lateralis, and vastus intermedius muscles

Lateral Cutaneous Nerve

Innervation/Anatomical Pathways — sensation to the lateral thigh

Obturator Nerve

Innervation/Anatomical Pathways — sensation to the medial thigh; obturator foramen of the hip

Saphenous Nerve

Innervation/Anatomical Pathways — sensation to the medial leg and medial ankle/foot

Sympathetic Trunk and Ganglia

Innervation/Anatomical Pathways — distributes fibers through the ramus communicans for sympathetic influence into spinal nerves