0-1 Chapter 13 the Spinal Cord Flashcards
paraplegia
paralysis of lower limbs
quadriplegia
paralysis of all four limbs
hemiplegia
paralysis of one side of the body only
Functions of the Spinal Cord
conduction
locomotion
reflexes
central pattern generators
are pools of neurons providing control of flexors and extensors that cause alternating movements of the lower limbs
spinal cord
cylinder of nervous tissue that arises from the brainstem at the foramen magnum of the skull
Number of Spinal Nerves
31 pair of spinal nerves
•first pair passes between the skull and C1
•rest pass through intervertebral foramina
spinal cord ends at
inferior margin ends at L1 or a little beyond
occupies the upper two-thirds of the vertebral canal
segment
part of the spinal cord supplied by each pair of spinal nerves
spinal cord divided into the
cervical, thoracic ,lumbar, and sacral regions
two areas of the cord are thicker than elsewhere
- cervical enlargement –nerves to upper limb
* lumbar enlargement –nerves to pelvic region and lower limbs
medullary cone (conus medullaris)
cord tapers to a point inferior to lumbar enlargement
cauda equina
bundle of nerve roots that occupy the vertebral canal from L2 to S5
meninges
three fibrous connective tissue membranes that enclose the brain and spinal cord
–separate soft tissue of central nervous system from bones of cranium and vertebral canal
Meninges of the Spinal Cord
from superficial to deep
dura mater, arachnoid mater, and pia mater
dura mater
–forms loose-fitting sleeve around spinal cord –dural sheath
–tough, collagenous membrane surrounded by
arachnoid mater
arachnoid membrane
subarachnoid space
arachnoid membrane
layer of simple squamous epithelium lining dura mater and a loose mesh of collagenous and elastic fibersspanning the gap between the arachnoid membrane and the pia mater
subarachnoid space
gap between arachnoid membrane and the pia mater
•filled with cerebrospinal fluid (CSF)
lumbar cistern
subarachnoid space inferior to medullary cone that contains cauda equina and CSF
pia mater
–delicate, translucent membrane that follows the contours of the spinal cord
terminal filum
fibrous strand of pia mater that extends beyond the medullary cone within the lumbar cistern
coccygeal ligament
formed from fusion of terminal filum and dura mater
•anchors the cord and meninges to vertebra Co1
denticulate ligaments
extend through the arachnoid to the dura
•anchors spinal cord to limit side to side movement