Spinal Cord
- inside vertebral column
- wrapped by the 3 layered meninges
- cerebral spinal fluid between 2 layers of meninges
- divided into 5 sections
- spinal nerves come out of spinal cord and go to the peripheral regions of your body
5 sections of spinal cord/ vertebral column
- cervical
- thoracic
- lumbar
- sacral
- coccygeal sections
Injuries in the cervical area of the spinal cord can cause…
… quadriplegia and even inability to breathe on your own
motor signals
efferent
sensory signal
afferent
main way of communicating info to your body
spinal cord
4 basic fiber types that emerge from spinal cord
1) Somatic (bones)
2) Visceral (organs)
3) Efferent (motor)
4) Afferent (sensory)
to skeletal muscles
General Somatic Efferent (GSE) - Dorsal Ramus
to smooth muscle, heart, and glands
General
Visceral
Efferent
(GVE)
from skin
General Somatic Afferent (GSA) - Dorsal ramus
from lungs and digestive tract
Genreal
Visceral
Afferent
(GVA)
GSE fibers
- to skeletal muscles
- Dorsal ramus
- Ventral ramus
- Ventral root
- Ventral horn
GVE fibers
- to smooth muscle, heart, and glads
- Rami communicantes
- Ventral root
- Ventral horn
GSA fibers
- from skin
- Dorsal ramus
- Ventral ramus
- Dorsal root
- Dorsal horn
GVA fibers
- from lungs and digestive tract
- Rami communicantes
- Dorsal root
- Dorsal horn
Dorsal Ramus
GSE and GSA fibers to/from dorsal body
Ventral Ramus
GSE and GSA fibers to/ from ventral body
Rami Communicantes
GVE and GVA fibers
Dorsal root
- sensory
- GSA and GVA fibers
Ventral root
- motor
- GSE and GVE fibers
Ventral horn
- motor
- GSE and GVE
Dorsal horn
- sensory
- GSA and GVA
line down the middle of the spinal cord
- Anterior median fissure
3 major landmarks of interior spinal cord
1) dorsal funiculus
2) lateral funiculus
3) Ventral funiculus
Funiculus=bundle
Major motor tracts
1) Lateral corticospinal (bulbar) tract
2) Anterior corticospinal tract
3) Rubrospinal tract
4) Lateral vestibulospinal
lateral corticospinal tract
- contralateral body movement
- left side of your brain controls right side of the body
- right side of your brain controls left side of the body
Anterior corticospinal tract
- controls trunk muscles
- standing, sitting, and walking posture
Rubrospinal tract
- flexor tone (flex muscles)
Lateral vestibulospinal tract
- extensor tone (extend muscles)
Major sensory tracts
1) Dorsal columns
2) Spinothalamic
3) Spinocerebellar
Dorsal colmuns
- Fasciculus gracilis and fasciculus cuneatus
- fine touch, pressure, proprioception
Spinothalamic
- pain, temperature, crude touch
Spinocerebellar
- proprioception
Spinal cord function
- relaying efferent and afferent information between body and brain
- mediating reflexes through the reflex arc