Page 103 - Zoo Animal Learning and Training

Chapter 5 Anatomy and Physiology 87

Neuron

Dendrites

Axon

Electrical Impulses

Neurotransmitter
Molecules

Receptor
Synapse

FIGURE 5.23 Neurons and synapses. Source: https://commons.wikimedia.org/wiki/File:Chemical_synapse_schema_cropped.jpg. Public
Domain.

The central nervous system (CNS) is made up of the running the animal’s body keeping everything going at a
brain and spinal column (Figure 5.22). normal pace. Normal heart beat and breathing, muscles
The brain is made up of the cerebrum, cerebellum, moving when told, digestion working properly, and so
and the brainstem. The cerebrum, the largest portion of on. However, life isn’t always normal!
the brain, is responsible for the higher functions which
include the senses, movement, and learning. The cere- Think of a mouse minding its own business searching for food.
bellum is smaller and coordinates muscle movement, When suddenly a big cat pounces. Without thinking, the mouse
posture, and balance. The brainstem is the relay center jumps away, running at full speed, trying to get away. If caught
connecting the other two parts to the spinal cord. It is or cornered, it would fight by biting and screeching at the cat.
responsible for the body functions of heart rate,
breathing, digestion, body temperature regulation, The mouse has demonstrated the sympathetic ner-
wake–sleep cycles, swallowing, coughing, vomiting, and vous system taking over as it responds to the stress of
so on. Deep underneath the cerebrum is the hypothal- almost being eaten. This is called the fight or flight
amus which is home to part of the nervous system called response. The heart is stimulated to beat faster, breathing
the autonomous nervous system (ANS) which responds speeds up, and the body gears up for a flight or fight in
in times of stress. The ANS has two systems of its own. a blink, no need for thought or decision. If the mouse
Most of the time the parasympathetic nervous system is gets away it would probably find a safe spot to calm down,