Spinal Cord
& Spinal
SP is cylinder of nervous tissue that arises from brain stem.
Passes through vertebral canal & terminates at level L1.
Nerves:
31 cranial nerves.
Divided into: Cervical, Thoracic, Lumbar & Sacral regions.
SC has 4 functions:
1. Conduction Info between body & brain
2. Neural Integration Info to execute appropriate responses
3. Locomotion Control repetitive movements & flexor/extensor muscles.
4. Reflexes Posture & muscle coord.
Protective responses to pain/injury.
Spinal cord covered by 3 meninges, which separate nervous tissue from internal aspects of the vertebrae.
Consists of 3 layers:
1) DURA MATER- thick, external fibrous layer; loose fitting sheath.
2) ARACHNOID MATER- thin, intermediate layer, arachnoid membrane.
3) PIA MATER- delicate, transparent membrane which follows the contours of the SC.
Consists of grey & white matter.
Grey Matter: Color from abundance of cell bodies & dendrites. H-shaped. Contains an ANTERIOR, POSTERIOR
AND LATERAL HORN.
White Matter: Areas with myelinated fibers & is arranged in columns. Contains nerve tracts.
SPINAL NERVES ARE PERIPHERAL NERVES:
Connect CNS to rest of body.
Exit through vertebral column through invertebral foramina.
Have root-valve: Indicate exact location from their origin in SC.
31 pairs of spinal nerves:
I. Cervical; 8 nerves
II. Thoracic; 12 nerves
III. Sacral; 5 nerves
IV. Coccygeal; 1 nerve
SPINAL NERVES CLASSIFIED DUE TO FUNCTION:
& Spinal
SP is cylinder of nervous tissue that arises from brain stem.
Passes through vertebral canal & terminates at level L1.
Nerves:
31 cranial nerves.
Divided into: Cervical, Thoracic, Lumbar & Sacral regions.
SC has 4 functions:
1. Conduction Info between body & brain
2. Neural Integration Info to execute appropriate responses
3. Locomotion Control repetitive movements & flexor/extensor muscles.
4. Reflexes Posture & muscle coord.
Protective responses to pain/injury.
Spinal cord covered by 3 meninges, which separate nervous tissue from internal aspects of the vertebrae.
Consists of 3 layers:
1) DURA MATER- thick, external fibrous layer; loose fitting sheath.
2) ARACHNOID MATER- thin, intermediate layer, arachnoid membrane.
3) PIA MATER- delicate, transparent membrane which follows the contours of the SC.
Consists of grey & white matter.
Grey Matter: Color from abundance of cell bodies & dendrites. H-shaped. Contains an ANTERIOR, POSTERIOR
AND LATERAL HORN.
White Matter: Areas with myelinated fibers & is arranged in columns. Contains nerve tracts.
SPINAL NERVES ARE PERIPHERAL NERVES:
Connect CNS to rest of body.
Exit through vertebral column through invertebral foramina.
Have root-valve: Indicate exact location from their origin in SC.
31 pairs of spinal nerves:
I. Cervical; 8 nerves
II. Thoracic; 12 nerves
III. Sacral; 5 nerves
IV. Coccygeal; 1 nerve
SPINAL NERVES CLASSIFIED DUE TO FUNCTION:
