Spinal Cord and Nerves

Organization of Nervous System Central Nervous System (CNS) = _______________ Peripheral Nervous System (PNS) = __________ CNS PNS

Peripheral Nervous System ___ _____

Spinal Nerves (______) Each pair of nerves located in particular segment (_____________________ etc.) Each nerve pair is _______ for the vertebra sitting above it (i.e. nerves ___________) __ pairs of _______ spinal nerves; *C1-C8 __ pairs of _______ spinal nerves; T1-T12 __ pairs of _____ spinal nerves; L1-L5 ___ pairs of ______ spinal nerves; S1-S5 1 pair of _________ spinal nerves; C0

Spinal Cord Segments

Meninges of Brain and Spinal Cord _________(deep) delicate highly vascular adheres to brain/sp cd tissue ____________ (middle) impermeable layer = barrier raised off pia mater by rootlets ____________ (most superficial) single dural sheath ______________ between arachnoid and pia mater contains CSF ___________________ Between dura mater and vertebra Contains fat and veins

Spinal Cord facts Passes inferiorly through _______ into _________ __ pairs of _____ nerves branch off spinal cord through ______ ___________ Spinal cord made of a core of ___ ________ surrounded by _____ _________ Pg 393

Spinal Cord Growth Runs from __________ to level of L1 (adults) Runs to level of L 3-4 (infants)

Regions of Spinal Cord Cervical _________ Lumbar ________ Coccygeal Cervical + Lumbar enlargements Cauda equina Conus medullaris Filum terminale Pg 393

Review of Neuron Anatomy Pg 339 Cell body ________ Axon Interneuron neuron Pg 342

Types of Nerve Fibers _____ = Afferent Nerve fibers = picked up by ________ throughout body (PNS) and carried TOWARDS ______________ (CNS) ______ = Efferent Nerve fibers = carried ___________ by nerves of PNS to innervate body’s muscles and glands Remember: SAME, Sensory- Afferent…..

4 Kinds of Nerve Fibers ______ Sensory – “_____ senses” touch, ______, temperature, vibration of body, muscles stretching, _________ _______ Sensory – “______ senses” Stretch, ____, temperature in organs (eg) _______, hunger, cramps _________ Motor – “body movement” _________contraction of skeletal muscles _________ – “organ movement” Contraction of ____________, glands = Autonomic Nervous System

Cross Section of Spinal Cord Gray Matter “________________ Gray Commissure = crossbar of “H” Central Canal = in gray commissure Posterior/Dorsal horns Anterior/Ventral horns Composed of ______________ Unmyelinated axons ___________ Neuroglia

Gray Matter _____________ ___________ _____________ ____________

Gray Matter Posterior Horns = made of _______ transmit info from cell bodies _______ of spinal cord ____ the sp cd Dorsal Root contains Sensory Fibers Somatic Sensory (SS) Visceral Sensory (VS) ______________-swelling in dorsal root that these _____________ pass through _________ = made of cell bodies of ------- that send axons OUT of sp cd to __________________ Ventral Root contains Motor Fibers Visceral Motor Somatic Motor