Cranial nerves and Spinal Nerves Biology 252 Anatomy and Physiology Lab II Fall 2017 Dr. Santos

CRANIAL NERVES Cranial nerve type function I Olfactory S smell II Optic vision III Oculomotor M 4 out of the 6 extraocular muscles that move the eye

IV Trochlear M 1 out of the 6 extraocular muscles of the eye V trigeminal M/S S- facial M- chewing VI Abducens 6TH extraocular muscle of the eye VII Facial S- face, mouth, anterior 2/3 of tongue M- muscles of facial expression, glands that produce tears, saliva and mucus

VIII Vestibulocochlear Hearing IX Glossopharyngeal M/S S- Posterior 1/3 of tongue M- muscles of throat/swallowing X Vagus S- skin of head and pharynx M- speech/swallowing/salivary glands *outside thoracic/abdominal viscera XI Accessory M Head/neck muscles XII Hypoglossal Muscles that move the tongue

Spinal nerves Ventral and dorsal root merge to form the spinal nerve The spinal nerve breaks off into a dorsal and ventral ramus The dorsal ramus innervates the posterior trunk (skin, joints, and muscles) The ventral ramus is divided into sections or networks of nerves called plexuses.

Cervical plexus C1-C4 Skin of head and neck and certain neck muscles Phrenic nerve- serves the diaphragm

Brachial plexus C5-T1 Axillary nerve- serves structures near axilla including the deltoid and teres minor muscles and skin around this region Musculocutaneous nerve- anterior arm muscles Radial nerve- posterior arm muscles Ulnar nerve- serves forearm flexors, intrinsic muscles of hands, and skin over medial hand Median nerve- forearm flexors, intrinsic hand muscles, skin over lateral and anterior hand

Lumbar plexus L1-L4, a small contribution from T12 Femoral nerve- motor innervation to most of the anterior thigh muscles and sensory innervation to skin of anterior and medial thigh, legs, and foot Lateral femoral cutaneous nerve- sensory to the anterolateral thigh

Sacral plexus L4- S4 1- Sciatic nerve- splits into 2 branches a) tibial nerve- muscles of the thigh, posterior leg and foot (m) and posterior leg and foot (s) b) fibular nerve- anterolateral leg and foot (m/s) 2- pudendal nerve- innervates muscles of pelvic floor and anogenital sphincters.