The document summarizes key aspects of the central nervous system, including: 1) The spinal cord contains grey matter on the inside consisting of neuron cell bodies, and white matter on the outside consisting of nerve fibers. 2) Reflex actions are immediate responses to a specific stimulus without conscious control, such as the knee jerk reflex. 3) A reflex arc consists of a receptor, sensory neuron, reflex center in the spinal cord or brain, motor neuron, and effector muscle or gland. 4) A conditioned reflex is a learned response acquired through experience that was originally not an effective stimulus, such as Pavlov's experiment where dogs learned to salivate at the sound of a tone through association with food.

1. Coordination and
response
White vs grey matter in spinal
cord and brain

2. Transverse sections of spinal cord at different levels

3. Central Nervous System
(spinal cord)
grey matter
(the butterfly
shape; consist central canal
of cell bodies (contains
of neurones) cerebrospinal
fluid  brings
white matter nutrients to
(consists of spinal cord)
nerve fibers)
 The opposite arrangement is found in the
cortex of the brain.

5. Spinal cord and spinal nerves
pg.261
- contains only sensory neurones
- aggregation - contains nerve
relay of cell bodies fibres from both
of sensory dorsal and ventral
neurones roots
- contains only motor neurones

6. Reflex actions
 An 1immediate response to a 2specific
stimulus 3without conscious control
 e.g. knee jerk, withdrawal of hand from hot
object
 Simplest form of response
 Classified under
– spinal reflex actions (controlled by spinal
cord)
- cranial reflexes (controlled by brain but not
will; in head region)

7. When we touch a hot object….

8. Reflex arc
Consists of
1. Receptor or sense organ
2. Sensory neurone
3. Reflex centre (spinal cord or brain)
4. Motor neurone
5. Effector (muscle/gland)

9. Conditioned reflex
a reflex action acquired from past
experiences or learning with a stimulus
which is originally ineffective in
producing the response
e.g Pavlov’s experiment

10. Pavlov’s Experiment
The dog's salivation to meat powder is an unconditional reflex
(no learning is involved)
Over time, however, the dog comes to salivate at the sounding of
the tone alone. When this occurs, a conditional reflex has
developed

11. Conditioned reflex

12. Conditioning?

13. The Nervous
System in Mammals
Quiz

14. Label the parts of
the neuron
 cell
body (13)
 dendrites (14)
 axon (15)
 myelin sheath (16).