1. Nervous System II Spinal Cord and Spinal Nerves
Meninges and Cerebro-spinal fluid (CFS)
Autonomic Function

2. Spinal Cord Cross Section

3. Spinal Cord Cross Section (drawing on handout--showing reflex arc)
White matter (myelinated “tracts”)
Gray matter (cell bodies)
Ventral horn--motor neurons
Dorsal horn--interneurons for sensory
Dorsal Root--sensory
Ventral Root--motor
Spinal Nerve
Dorsal Ramus (to dorsal mm., skin)
Ventral Ramus (to ventral limbs mm., skin)
Dorsal Root Ganglion
Sensory Neuron
Somatic Motor Neuron

4. Spinal nerve (cross section through thorax--on handout)
Dorsal Root Ganglion
Ventral root
Spinal Nerve
Dorsal Ramus
Ventral Ramus
(Where would you find the ventral ramus relative to the ribs)
(Look for lateral cutaneous nerves on your cat!!)

5. Spinal Cord showing meninges

6. What are meninges? Connective tissues around spinal cord
For protection
For nutrition
Three layers
Pia mater
Arachnoid mater
Dura mater

7. Subarachnoid space (where CSF flows) Arachnoid mater (middle)
Pia mater (deep)
delicate
highly vascular
adheres to brain/sp cd tissue
Subarachnoid space (where CSF flows)
Arachnoid mater (middle)
impermeable layer = barrier
raised off pia mater by rootlets
Spinal Dura Mater
single dural sheath

8. Sympathetic and Parasympathetic
Why double innervation?
Paraympathetic keeps “normal” rhythms, functioning--all calm
Sympathetic is “fight or flight” fear response

9. How are Para/Sympa different?
Parasympathetic
Sympathetic
Location
Cranial, sacral
Thoracic, Lumbar
Ganglia
In target organs
Close to spinal cord
Neuro-
Transmitter
Acetylcholine (calmer)
Norepinephrine (adrenalin!!)
Effect
Table 15.2
For details