NERVOUS SYSTEM
AND ANIMAL
BEHAVIOR
•
•
•
What factors influence behavior?
How does evolution influence behavior?
Explain examples of learned vs. innate
behaviors?
Compare and contrast Bird brains and human brains
THE NERVOUS SYSTEM
The nervous system
receives and
interprets signals
Neurons –
specialized cells
that receive and
respond to stimuli
Nerves – bundles of
neurons
THE NERVOUS SYSTEM
THE NERVOUS SYSTEM
3 categories of neurons:
1. Sensory neurons
carry information to
the CNS
2. Motor neurons carry
information away
from CNS toward
effector tissue
3. Interneurons are
located between
sensory and motor
neurons
Sensory receptors – detect sensory input
•These are neurons or other cells
that communicate with sensory
neurons
•They detect changes in conditions
inside or outside the body
 The spinal cord also is a reflex center
 Reflexes – automatic responses to
stimuli
 Reflex arc – prewired circuit of
neurons
 Sensory neuron receiving stimulus
 Interneuron transmitting information
 Motor neuron sending message to
muscle
 Reflexes allow a per son to react
quickly to dangerous stimuli
 Withdrawal reflex – when touching
something hot
 The pain stimulus travels from the spinal cord to the
brain and takes a little longer than the reflex
 You have removed your hand from the heat before
you feel the pain
21.2 THE BRAIN
The brain is where
decisions are
reached and bodily
activities are
directed and
coordinated
The human brain is
roughly the size of
a small cantaloupe
THE BRAIN
 The brain is
housed in the
skull and sits
inside a liquid
bath called the
cerebrospinal
fluid for
protection and
cushioning
CEREBRUM
 Largest part of brain
 Contains many folds and bumps
 Sulci vs. gyri
 Corpus callosum is found b/t the L and R
 Responsible for reasoning, intellectual
fxn and critical thinking
CEREBELLUM




Regulates balance
body position
Posture
Muscle coordination
BRAIN STEM
 Midbrain
 Pons
 Medulla oblongata
MEDULLA
OBLONGATA
 Vital Reflex center
Visceral activities:
blood pressure,
respiratory
cardiac
 Part of the brain stem
 Injuries often fatal
PONS
b/t midbrain and
medulla
oblongata
Regulates rate
and depth of
breathing
Homeostatic
mechanisms
CEREBRUM
There are 2 hemispheres, each divided into 4 lobes
1.
2.
3.
4.
The temporal lobe
involved in auditory and
some visual information;
memory and emotion
Occipital lobe processes
visual information from
eyes…
Parietal lobe processes
information from touch;
self-awareness
Frontal lobe processes
involuntary muscle
movements; planning
and organizing future
expressive behavior
 Cerebral cor tex – wrinkled
outer sur face
 If unfolded, a human
cerebral cor tex would be the
size of a 16’ pizza
 Lots of surface area in a
small space
 F i s s u re – de e p g ro ove di v iding
t h e c e re brum a n d c o r tex
 Divided into right and left
cerebral hemispheres
 C o rp us c a llo sum – bun dl e o f
n e r ve fi be r s a t ba s e o f fi s sure
– l i n king t wo h e m isph eres
THE BRAIN
 Functions of the brain are
divided between the right
and lef t hemispheres
 The left hemisphere
controls the right half of
the body
 The right hemisphere
controls the left half of the
body
 The lef t hemisphere controls
speech, reading and ability
to solve mathematical
problems
 The right hemisphere
controls spatial ability and
musical and ar tistic creation
CEREBELLUM, CEREBRUM, OR BRAIN STEM
1. Medulla oblongata located here.
2. Regulates balance
3. Cerebral cortex is located here
4. Capacity for intellectual function resides here
5. Breathing rate is regulated here
6. Has folded layers with bumps and grooves
7. Regulates posture
8. Contains the corpus collosum
9. Pons located here
10. Leads to spinal cord
NEURON STRUCTURE
 Neurons are highly
specialized cells
that usually don’t
divide
 Damage to
neurons can’t be
repaired by cell
division – many
times results in
permanent
impairment




Dendrites
Soma
Axon terminals
Axon
NEURON
STRUCTURE
 Many neurons have axons
covered in a protective
layer – myelin sheath –
that insulates to prevent
sideways transmission
 Increases speed of
transmission (100x)
 composed mainly of
lipids and is white like
animal fat
 Nervous tissue of
myelinated cells is called
white matter
NEURON STRUCTURE
 Gray matter are unmyelinated neurons
Transmit impulses slower
•Potassium channels are ‘leaky’ and allow potassium to passively move to the outside
•The sodium-potassium pump in the neuron membrane moves sodium out and potassium
in
•Using ATP, the sodium-potassium pump moves 3 Na+ out for every 2 K+ in
•This restores the potassium levels in the cell
•The depolarization – loss of charge difference – moves in a wave down the cell
 Repolarization –
when potassium
i o n s leave and
internal cell state
is more negative
than outside
SYNAPTIC TRANSMISSION
 After traveling along
the axon, the signal
must be passed
along to the next
neuron
 Most neurons are
not physically
connected
 Synapse – the gap
between two
neurons
COMMUNICATION BET WEEN NEURONS, OR
MUSCLES, OR GLANDS
ANIMATIONS OF SYNAPTIC
TRANSMISSION
http://highered.mcgrawhill.com/sites/0072495855/student_vie
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he_neuromuscular_junction__quiz_3_.ht
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http://science.education.
nih.gov/supplements/nih
2/addiction/default.htm
What would occur if
the neurotransmitter
stayed in the
synapse?
 Af ter the neurotransmitter
causes the response
 Removed from synapse
 Enzymes break down
neurotransmitters
 Reuptake – some
neurotransmitters are
reabsorbed by the
presynaptic neuron
 By enzymatically breaking
down and reuptake of
neurotransmitter s, there is
no continuous stimulation of
the postsynaptic cell
SYNAPTIC
TRANSMISSION
NEUROTRANSMITTERS
 Chemicals that are released from one neuron at the
presynaptic nerve terminal. Neurotransmitters then cross the
synapse where they may be accepted by the next neuron at a
specialized site called a receptor.
NOREPINEPHRINE
AKA: ADRENALIN
 Released from brain and ANS
 Adrenal gland




Excitatory
Sense of feeling good
Monoamine
Can be used to manage hypertension
DOPAMINE
Released from brain (CNS)
 hypothalamus
Receptors: heart, kidneys, bld
vessels
Inhibitory
sense of feeling good
Parkinson’s Disease
amine
SEROTONIN
Brain (CNS)
Regulates endocrine activity
(hormonal controls)
Leads to sleepiness
 Controls sleep/wake cycles
amine
Inadequate amounts:
 Severe depression and
obsessive/compulsive disorders,
anger issues, and eating
disorders
ENDORPHINS






Neuropeptide
Produced in brain (CNS)
Pain relief: inhibitory
Released in times of pain or stress
Elevated levels cause disease known as Addison’s disease
Structure is similar to???
 morphine
NEUROTRANSMISSION, ALZHEIMER’S,
DEPRESSION, PARKINSON’S, AND ADD
 Depression is a
disease
 Feelings of
helplessness and
despair and thoughts
of suicide
 It may involve three
neurotransmitters
 Serotonin &
dopamine (inhibitory)
and norepinephrine
(excitatory)
Parkinson’s
disease is a
malfunctioning of
neurons that
produce dopamine,
causing nerve cells
to fire without
regulation
 Tremors, rigidity and
slowed movements
NEUROTRANSMISSION, ALZHEIMER’S,
DEPRESSION, PARKINSON’S, AND ADD
 ADD may be due to
abnormal levels of
dopamine
 Dopamine controls
emotions as well as
complex movements
 May be due to
overabundance of
dopamine receptors
on presynaptic cells –
too much reuptake
RITALIN ®
 Ritalin is thought to increase
dopamine’s ability to
stimulate postsynaptic cells
 Block reuptake receptors in
presynaptic cells
 Dopamine in synapse longer
 Stimulants in high doses
result in
 Euphoric feeling
 More energy and endurance
 Sense of power
 Feeling of mental sharpness
 Af ter the stimulants wear of f,
user feels
 Heightened fatigue
 Insomnia
 Poor concentration
 Irritability
 Tearfulness
 Depression
DRUGS ALTER CHEMISTRY IN THE
BRAIN….ALTERING BEHAVIOR!
https://www.youtube.com/watch?v=90cj4NX87Yk
LABEL THE NEURON BELOW
M Y E L I N , N U C L E U S , D E N D R I T E , A X O N T E R M I N A L , S H WA N N C E L L , S O M A , N O D E S O F
RANVIER
1
7
6
2
5
3
4
SENSORY STRUCTURES
ACCOMMODATION
TAPETUM LUCIDUM
ANIMAL BEHAVIOR
Components
 Behavior: an action that
an individual carries out
in a response to a
stimulus
 Stimulus: action or agent
that changes activity of
an organism
 Response: biological
reaction resulting from a
stimulus
Examples
 Noise startles
 Bacterial produce an
immune response
ANIMAL BEHAVIORS
Behavioral Cycles
(responds to natural cycles )
Seasonal
Ex:
Migration
Daily
Ex:
Circadian
rhythms
Social Behavior
(Interactions with others thru)
1. Courtship
2. Building
homes
3. Hunting
4. Protection
5. Fighting
rivals
Competition
And Aggression
Claim or
protect
territory
Communication
(Depends on senses)
1. Visual
signals
2. Chemical
signals
3. Sound
4. language
CLASSES OF BEHAVIOR
 Survival strategies
1. Foraging:
2. Anti-predator behavior
3. Cyclic behavior (seasoning, circadian rhythms)
 How does nocturnal behavior benefit some animals but not others?
 Modes of Communication
1. Signals help influence behavior of animals
 (chemicals, tough, sound, language)
 Reproductive Strategies





Social
Territorial
Courtship (sexual selection, competition)
Prenatal care
Cooperative behaviors
HOW DOES THE BODY RESPOND?
 Sensory systems gather
information about the
environment
 The info will trigger
responses to the nervous
system which a produces
a response
INFLUENCES ON BEHAVIOR
(INTERNAL VS. EXTERNAL)
 Genes (Nature)
 May increase the likelihood
that an organism will
display a behavior
 Tongue rolling, nocturnal
activity, aggressiveness
 Environment (Nurture)
 Helps to determine what
traits are displayed
EVOLUTION OF BEHAVIOR
Natural selection
 Traits are favored that
increase an individual’s
reproductive success.
 Over time, those
beneficial traits
become more and more
common in the
population
Lions
 Male lions will kill all
lion cubs after taking
over a tribe.
 Why?
EVOLUTION OF BEHAVIOR
 Natural selection favors traits that increase an organisms
reproductive success.
Innate behavior
Learned behavior
 Habituation
 An animal learns to no
longer respond to a
frequent harmless or
unimportant stimulus
 Fixed action patterns
 Triggered by a stimulus
in the environment and
do not stop once the
behavior has begun.
 Reasoning
 Problem solving
ASSOCIATIVE LEARNING
Classical Condition
Operant conditioning
SENSITIVE PERIODS
Imprinting
 Occurs when an
animal develops a
particular response to
an object or organism
only during a brief
period early in life.
What are the
benefits of
imprinting?
CLASSES OF BEHAVIOR:
SURVIVOR
 Foraging Behavior
FORAGING
 Woodpecker https://www.youtube.com/watch?v=wugUc0fi54k
ANTI-PREDATORY BEHAVIOR
 https://www.youtube.com/watch?v=RamV - AjID8E
CLASSES OF BEHAVIOR:
COMMUNICATION
 Sight
CUCKOO BEHAVIOR
 European cuckoos exhibit
brood parasitism
 Female lays eggs in a nest of
another bird
 Once the eggs hatch, it reacts
to any other object in the nest
by pushing it out…thus it
receives all the parental care
from the surrogate parents
 Soon, it becomes larger than
the parent that is trying to fee
it.
REVIEW QUESTIONS
Please answer questions on ½ y.o.p.
1. What is the fundamental unit of the Nervous System?
2. What part of the brain is responsible for motor
coordination and balance?
3. What part of the brain controls vital organs? (like
breathing rate/depth)
4. Describe how do neurons communicate with each other?
5. What are the two categories of animal behaviors?
6. Discuss how behaviors are influenced?