PNS Flashcards
Endoneurium
Connective Tissue
Surrounds individual axons
Perineurium
Connective Tissue
Surrounds axon groups to form fascicles
Epineurium
Connective Tissue
Surrounds entire nerve
Myelinated Axon
Insulation
Speeds up transmission
Unmyelinated Axon
Myelin still present, but not heavily wrapped
Fascicles
Axon bundles
Schwann Cell
Found in PNS
Myelinates axons
Cervical Plexus
C1-C4
Skin: superficial neck structures, skin of neck, posterior portion of head
Ansa Cervicalis
Phrenic Nerve (C3-C5) - Diaphragm
Lesser Occipital Nerve
Supraclavicular Nerves (C3-C4)
CN XII (Hypoglossal)
CN XI (Accessory)
CN XII (Hypoglossal)
Cranial Nerve (not from Cervical Plexus)
Innervates intrinsic/extrinsic tongue muscles
CN XI (Accessory)
Cranial Nerve (not from Cervical Plexus)
Innervation: Sternocleidomastoid + Trapezius
Lesser Occipital Nerve
C2
Goes up on back of skull
Innervation: skin on back of ear and scalp
Ansa Cervicalis
C1 - Superior Root
C2-C3 - Inferior Root
Supraclavicular Nerves
C3-C4
Innervation: skin above and below clavicle
Phrenic Nerve
C3-C5
Innervation: Diaphragm
Brachial Plexus
Roots: C5-T1
Trunks: Superior (C5-C6), Middle (C7), Inferior (C8-T1)
Divisions: Anterior, Posterior
Cords: Lateral, Medial, Posterior
Branches: Musculocutaneous, Axillary, Radial, Median, Ulnar, Long Thoracic