Download Neuron Unit 3A

Neural and Hormonal Systems
Will Explain Why We FEEL……
Nervous
Strong
Pain
Sick
• http://www.youtube.com/watch?v=6BgfKq
c3qhs&list=PL2920A92123EAF834&index
=83&safety_mode=true&persist_safety_mo
de=1&safe=active
Biological Psychologists
• Study the links between biological activity
and psychological events
• Study the connections between stress and
disease, hunger and sex to name a few
• Not a new idea- phrenology – the study of
bumps on our head to determine our
character and abilities WRONG!
It all Starts with the Neuron
Neuron Structure
Neurons do NOT touch each otherthe space in between is call the
Types of Neurons
Sensory Neurons
Motor Neurons
Inter Neurons
Sensory Neurons
(Afferent Neurons)
• Take information from the
senses to the brain.
Inter Neurons
• Take messages
from Sensory
Neurons to
other parts of
the brain or to
Motor Neurons.
Found only in
Spinal Column
and brain
Motor Neurons
(Efferent Neurons)
• Take information from brain to the rest of
the body. Axons in motor neurons can be 4
feet long. Fun Fact: A giraffe has a neuron
from its toe to neck is 15 feet long
Neuron Video
• http://www.youtube.com/watch?v=cUGuW
h2UeMk
• http://www.youtube.com/watch?v=FR4S1B
qdFG4&list=PL2920A92123EAF834
How a Neuron Fires
It is an electrochemical
process
• Electrical inside the neuron
• Chemical outside the neuron
(in the synapse in the form of
a neurotransmitter).
• The firing is call Action
Potential.
The All-or None Response
• The idea that
either the
neuron fires or
it does not- no
part way firing.
• Like a gun or a
toilet flushing
Steps of Action Potential
• Dendrites receive neurotransmitter from another
neuron across the synapse.
• Reached its threshold- then fires based on the
all-or-none response.
• Process continues down axon to the axon
terminal.
• Terminal buttons turns electrical charge into
chemical (neurotransmitter) and shoots message
to next neuron across the synapse.
How Neurons Communicate
Neurotransmitters
• Chemical messengers released by terminal
buttons through the synapse.
• NT attach to (bind) to receptors on the
second cell. Depending on the site they will
either excite an action potential or inhibit
the action potential molds the connections
that are made in our brains by outside
events
Acetylcholine
• The best understood NT. Plays a role in
learning and memory. ACh is the messenger at
every junction of a motor neuron & skeletal
muscle. If Ach transmission is blocked like
anesthesia, muscles can’t contract
• Too
And you
are paralyzed
much
and you will
Not enough and you will….
Lack of ACH has been linked to
Alzheimer’s disease. ACh neurons
deteriorate
Dopamine
• Its function is motor
movement and alertness.
(large NT)
Lack of dopamine
is associated
with Parkinson’s
Overabundance
disease.
is associated
with
schizophrenia.
Cocaine mimics
Serotonin
• Function deals with mood
control, hunger sleep and
arousal.
Lack of serotonin
has been linked
to depression.
Mimics LSD and
ecstasy
Endorphins
• Function deals with pain
control. Naturally occurring
opiate
We become addicted
to endorphin causing
feelings.
Substance P
• The body’s pain neurotransmitter. This NT
works in opposition with endorphins to
regulate pain. Substance P signals the body
it is in pain and then endorphins are
triggered to inhibit the pain signal
Agonists and Antagonists
Agonists/Antagonists
• Some opiates are agonists
and produce a temporary
high. Agonists mimic NT
• Venom from a black
widow spider is an
agonists for Ach floods
the synapses and result is
violent vomiting,
convulsions or death
• Antagonists bind to receptors
but they block a NT
functioning. Botulin from bad
food can paralyze because it
blocks Ach release
• Note: Botox from Botulin
smooth out wrinkles because it
paralyzes your muscles under
the skin
Botox and its effects
• http://www.youtube.com/watch?v=BQIElB
kgOmY
Divisions of the Nervous
System
Sympathetic Nervous System
Flight or Fight Response
A Simplified Neural Network
Neurons that learn to work
together as a team.
Did you know?
• Sensory neurons connect to the spinal cord
in the back?
• Motor neurons connect in the front of the
spinal cord
• So it is possible to lose feeling in lower
portions of the body in a spinal injury but
retain the ability to move if the spinal cord
is not completely severed
A Simple Reflex
http://www.youtube
.com/watch?v=HrMi
4GikWwQ&list=PL2
920A92123EAF834
&index=84
The Endocrine System
A system of glands that secrete
hormones.
Similar to nervous system,
except hormones work a lot
slower than neurotransmitters.
Hormones
Neurotransmitters
The Major Endocrine Glands
Endocrine System
• Pituitary gland- the master gland
• Adrenal – release epinephrine and
norepinephrine ( flight or fight response)
• Hormones affect heart rate, blood pressure,
blood sugar
• Affect lingers after event
• Need to create Homeostasis