The Nervous System Spinal Cord Structure and Function
- Slides: 7
The Nervous System Spinal Cord- Structure and Function Pages 252 -255
Review of nervous system terms Neurons = nerve cells Nerve cell bodies = ganglia (ganglion is singular) Bundles of nerve fibers: In the CNS = tracts In the PNS = nerves
Spinal Cord Begins at the foramen magnum of the skull Terminates around first or second lumbar vertebra conduction pathway Approaching/Exiting the brain Afferent vs. Efferent 31 pairs of spinal nerves arise from the spinal cord Cauda equina (horse’s tail) a dense collection of spinal nerves at the inferior end Meninges cover the spinal cord © 2015 Pearson Education, Inc.
Figure 7. 20 Anatomy of the spinal cord, posterior view. Cervical spinal nerves C 8 Dura and arachnoid mater Thoracic spinal nerves T 12 End of spinal cord Lumbar spinal nerves Cauda equina End of meningeal coverings L 5 S 1 Sacral spinal nerves S 5
Figure 7. 21 Spinal cord with meninges (three-dimensional view). Dorsal root ganglion White matter Central canal Dorsal (posterior) horn of gray matter Lateral horn of gray matter Spinal nerve Ventral (anterior) horn of gray matter Dorsal root of spinal nerve Ventral root of spinal nerve Pia mater Arachnoid mater Dura mater ANTERIOR
Spinal Cord Anatomy Gray Matter: Horns of the spinal cord Collection of neuron cell bodies Dorsal (posterior) horns (SENSORY) house interneurons Receive sensory info from neurons in the dorsal root Anterior (ventral) horns (MOTOR) house somatic (voluntary) motor neurons Send motor information out ventral root White Matter: myelinated axons the central canal is filled with CSF
Figure 7. 21 Spinal cord with meninges (three-dimensional view). Dorsal root ganglion White matter Central canal Dorsal (posterior) horn of gray matter Lateral horn of gray matter Spinal nerve Ventral (anterior) horn of gray matter Dorsal root of spinal nerve Ventral root of spinal nerve Pia mater Arachnoid mater Dura mater ANTERIOR