Download Powerpoint

The Animal Nervous System
And its Role in Animal Behavior
Unit 7, Lesson 1
1
For years, people have asked the question,
“Can animals think?”
A study of the nervous system of
agricultural animals leads us to
the study of animal behavior.
2
Vertebrates have many similarities . . .
• Central Nervous
•
System consisting of
brain and spinal cord.
Peripheral Nervous
System consisting of
nerves that carry
information to and
from the rest of the
body to the central
nervous system.
Did you know? Protein is vital in
the development of vertebrate
soft tissues, which includes the
nervous system.
3
There are some differences . . .
• The overall size of brains differ, where some
•
•
brains are larger than others
There are noticeable structure differences in
particular places when comparing brains
In some brains the cerebral cortex is
particularly smooth and in some others there is
lots of cortical folding
4
What do these differences mean?
• As brains have evolved,
areas that control senses,
instinct and coordination
have became
predominant.
• In a human brain, the
area dedicated to
thinking (cerebrum)
covers up and dominates
anything else. It also has
folds that increase the
surface area.
5
6
So, can animals think?
•
•
•
This is a very controversial topic!
Some believe that we tend to only measure
intelligence in terms of human understanding, so
we see animals as lesser when they might have
some areas that are more developed than ours.
Others believe that animals are acting off a
combination of learned responses and instinct.
Others see them as having equal intelligence to
humans and fight for their rights.
What do you think?
7
There is no clear answer.
• The area of animal intelligence is
constantly being studied by hundreds of
scientists.
• However, the study of animal behavior is
essential to the production of agricultural
animals. This is the area we will focus on.
8
Ethology
• The scientific study of an animal’s
behavior in response to its environment.
– Knowledge of animal behavior is essential to
understanding the whole animal and its ability
to adapt to various management systems.
– Involves the interaction of inherited abilities
and environmental experiences.
– Producers who understand patterns of
behavior can manage and train animals more
effectively.
9
Instinct
• Reflexes and
responses an
animal has at birth
– At birth, all
mammals have
instinct to nurse.
– After hatching,
chicks begin
pecking to obtain
feed.
10
Habituation
• Learning to respond without thinking.
– Response to a certain stimulus is established
as a result of habituation.
– Conditioning is learning to respond in a
particular way to stimulus as a result of
reinforcement when the proper response is
made.
• Reinforcement usually in the form of a reward.
• Trial and error is used until correct response is
found.
• Example: newborn searches for place to nurse
because its hungry and receives reward of milk
when proper place is found.
11
Reasoning
• The ability to respond
correctly to a stimulus
the first time that a
new situation is
presented.
12
Intelligence
• The ability to learn to adjust successfully
to certain situations.
– Short-term memory
– Long-term memory
13
Pavlov’s Dogs
• Ivan Pavlov worked to unveil the secrets of the
•
digestive system and he also studied what
signals triggered related phenomena, such as
the secretion of saliva.
When a dog encounters food, saliva starts to
pour from the salivary glands located in the back
of its oral cavity.
– saliva needed in order to make the food easier to swallow
• Pavlov became interested in studying reflexes when he
saw that the dogs drooled without the proper stimulus.
– No food was in sight - their saliva still dribbled.
– Every time the dogs were served food, the person who served
the food was wearing a lab coat. Therefore, the dogs reacted as
if food was on its way whenever they saw a lab coat.
14
Pavlov’s Dogs
• Pavlov then tried to figure out how
•
•
these phenomena were linked. For
example, he struck a bell when the
dogs were fed. If the bell was
sounded in close association with
their meal, the dogs learned to
associate the sound of the bell
with food. After a while, at the
mere sound of the bell, they
responded by drooling.
This is called conditioning.
He was awarded the Nobel Prize
in Physiology or Medicine in 1904
Visit http://nobelprize.org/medicine/educational/pavlov/
And play Pavlov’s Dog Game to illustrate this principle.
15
16
Extend your thinking:
Compare and contrast these brains.
Who do they belong to?
17