November 14, 2016 Objective: Journal: To describe the anatomy and physiology of the spinal cord To list and describe the function of the protective coverings found around the spinal cord Journal: What do you think the function of the spinal cord is? Hand in your reaction time lab!

Spinal Cord

Spinal Cord Neural information superhighway that runs inside your vertebral column to the foramen magnum Runs from the second lumbar vertebrae to the brain stem

Spinal Cord Nerve Names Named for their corresponding vertebrae Cervical Nerves: C1 – C8 Thoracic Nerves: T1 – T12 Lumbar Nerves: L1 – L5 Sacral Nerves: S1 – S5 Coccygeal Nerve located at the coccyx

Spinal Cord External Anatomy Spinal cord ends at L2 at the conus medullaris Cauda equina – nerves in cerebrospinal fluid that extend from the conus medullaris

Meninges Series of protective membranes within the bone that cover the brain and spinal cord Help set up the layers of cushioning and shock absorbers for the brain and spinal cord

Layers of Protection around the CNS Vertebrae Epidural space Dura mater Subdural space Arachnoid mater Subarachnoid space Pia mater Spinal Cord

Epidural Space Filled with fat and blood vessels

Dura Mater Made of thick, fibrous tissue

Subdural Space Filled with cerebrospinal fluid

Arachnoid Mater Made of a delicate layer of collagen and elastic fibers surrounded by cerebrospinal fluid Acts as a shock absorber Can transport nutrients, dissolved gases, neurotransmitters and waste Contain arachnoid villi

Subarachnoid Space Cerebrospinal fluid cushioning for the CNS

Pia mater Contains blood vessels that supply blood to the brain and spinal cord

Spinal Cord Internal Anatomy Anterior Medial Fissure: deep groove on the CNS Posterior Median Sulcus: shallow groove on the CNS

Gray Matter Horns Cell body regions that are unmyelinated Three Types: Dorsal Horns: Involved in sensory functions Ventral Horns: Involved in somatic motor functions Lateral Horns: Involved in autonomic functions

White Matter Columns Nerve tracts (similar to axons) that run up and down the spinal cord, to and from the brain Like communication wires that transport information

Spine Extending to Nerves Central Canal: central cavity filled with CSF Spinal Roots: project from the spinal cord Dorsal Root Ganglion: carries sensory information Ventral Root Ganglion: carries motor information Spinal Nerves: carries both sensory and motor information from the body to the spinal cord

Plexus Complex branching patterns that extend from the spinal cord to peripheral structures Types Nerves C1 to C4 - neck, shoulders, and diaphragm Nerves C5 to C8 & T1 - upper extremities Nerves T12, L1-L5, and S1-S4 - abdominal wall & lower extremities