D5.1 Overview of CNS PNS and Spinal Cord_NR.pptx

OVERVIEW OF CNS, PNS & SPINAL CORD Objectives: Understand the difference between the CNS and PNS H E AT H E R G A R V I N , P H D , D - A B FA Central Nervous System Brain & Spinal Cord Peripheral Nervous System Everything else Ne...

OVERVIEW OF CNS, PNS & SPINAL CORD Objectives: Understand the difference between the CNS and PNS H E AT H E R G A R V I N , P H D , D - A B FA Central Nervous System Brain & Spinal Cord Peripheral Nervous System Everything else Nerve Basics neuron Axon Cell body Info out Cell body Dendrites Synapse Info in to cell functional communication btw neurons axon nerve impulse vasa nervorum Thus, nerves can carry multiple endoneurium types of nerve fibers,.e.g, somatic perineurium sensory, somatic motor, autonomic…. epineurium because composed of numerous axonsCell bodies lie in a nerve is a collection of axons CNS or in ganglia surrounded by connective tissue sheaths  31 pairs of spinal nn C1 C1-C7 exit superior C1 C2 to their vertebra # brain C8 exits inferior to Cervical C7 C7 C7 T1 C8 enlargement T2 T1 Brachial plexus = upper limb All others exit inferior to their vertebra # Lumbar Even those in T12 T1 enlargement cauda equina L1 2L1 L Conus medullaris Lumbosacral plexus= lower limb 2 Cauda equina L5 S1 L5 S1 S5 Co  Note on Spinal Cord Development 8 weeks 24 weeks Neonate Adult In an embryo spinal cord and vertebral column are the same length. The vertebral column grows faster than the spinal cord resulting in higher level of conus medullaris in adult, and creation of cauda equina. Dural sac remains with vertebrae throughout development. Spinal Cord White Matter Gray Matter Myelinated axons & Collection of cell bodies & dendrites (neuronal cell unmyelinated neuronal processes) processes Dorsal Horn Ventral Horn Lateral Horn (T1-L2 only) Can you tell what side is Dorsal vs Ventral? Test Yourself A)Transverse foramen B)Vertebral foramen C)Intervertebral foramen Test Yourself A)Transverse foramen B)Vertebral foramen C)Intervertebral Questions? [email protected]