Chap 16 Flashcards
Spinal cord ends…
approx. L1 vertebrae
Number of vertebrae/ section
8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal
spinal cord meninges
vertebra, epidural space, dura mater, arachnoid mater subarachnoid space, pia mater
anterior horn
motor neurons
lateral horns
t1-L2 autonomic motor
sympathetic motor neurons
posterior horns
sensory neurons
conus medullaris
cone shaped, tapering at end of the spinal cord (L1)
cauda equina
“horse tail” axons of spinal nerves projecting inferiorly from spinal cord to lumbar and sacral levels
filum terminale
strand of pia mater extending from the conus medullaris (white)
cervical enlargement:
neurons ot upper limbs
lumbsacral enlargement
nuerons to lower limbs
anterior median fissure
motor
posterior median sulcus
sensory
anterior rootlets
cmbine to form anterior root which contains anterior motor axons only
posterior rootlets
combine to form posterior root and contain only sensory axons.
Dermatome:
a segment of skin supplied by a single spinal nerve
C3 collar
T4 nipple
T10 belly button
Nerve plexuses
Cervical Brachial Lumbar Sacral
cervical plexuse
innervates anterior neck muscles and diaphragm
brachial plexuse
innervates pectoral girdles and upper limbs
lumbar plexuse
innervates pelvic girdles, thighs
sacral plexuse
innervates lower extremities
Reflexes
rapid, automatic, involuntary reactions of muscles or glands to a stimulus
Ipsilateral reflex
both receptor and effector organs on same side of spinal cord
Contraloateral reflex
sensory receptors and effector organs on opposite body side.
Monosynaptic reflex
simplest reflex ex: patellar reflex
polysynaptic reflex
involves a number of synpases and interneurons (ex. Pain withdrawal)
