Download Biopsychology Revision

Biopsychology Revision
What do you need to know?...
• Biopsychology
• The divisions of the nervous system: central and
peripheral (somatic and autonomic).
• The structure and function of sensory, relay and
motor neurons. The process of synaptic transmission,
including reference to neurotransmitters, excitation
and inhibition.
• The function of the endocrine system: glands and
hormones.
• The fight or flight response including the role of
adrenaline.
Key assumptions of biopsychologists
• Biopsychologists assume that behaviour and
experiences are caused by activity in the
nervous system
• The nervous system transmits signals for
communication via the billions of nerve cells
(neurons) it houses
• These nerve cells communicate with each
other, through electrical and chemical
messages, within the body and the brain.
The divisions of the nervous
system…
On your whiteboard… see if
you can remember the
divisions of the nervous
system.
Your diagram
should look like
this
Our nervous system has 2 parts – the CNS and
the PNS
CNS = Central
nervous system
= The brain and
spinal cord
PNS = Peripheral
nervous system =
all other nerve cells
around the body
Central Nervous system
• Brain and spinal chord
• some parts of the brain are involved
in vital functioning, others are
involved with problem solving and
planning
• Spinal chord transmits messages to
and from the brain to the
peripheral nervous system (PNS). It
is also involved in reflex actions
such as the startle response.
Our peripheral nervous system has 2 parts –
the SNS and the ANS
SNS = somatic nervous system
Transmits info to and from senses and to and
from CNS
= voluntary movements
= skeletal muscles and bones
ANS = AUTONOMIC NERVOUS
SYSTEM
Transmits info to and from internal
organs to sustain life processes
= involuntary movements
= heartbeat & breathing
Our autonomic nervous system has 2 parts –
the sympathetic and the parasympathetic
branch
SYMPATHETIC
PARASYMPATHETIC
BRANCH
BRANCH
= activates arousal
= conserves and stores
and energy
resources
The 2 branches
work
antagonistically –
in opposition to
each other
These two
systems are
involved in
the fight or
flight
response.
Glands & hormones
• Most hormones affect cells in several
organs or throughout the entire body,
leading to powerful responses
• E.g thyroid gland produces the hormone
thyroxine (increases heartrate)
• Also affects chemical processes taking
place in cells – affects growth rates
What do you need to know?...
• Biopsychology
• The fight or flight response including the role of
adrenaline.
Fight or Flight Response
Increase
oxygen intake
Release stored
glucose
Divert resources
away from
digestion
Ready to expend energy,
either by fighting or by running away
Fight or flight?
• This leads to physiological changes in the body which
are summarised in the table below…
Sympathetic state
Parasympathetic state
Increases heart rate
Decreases heart rate
Increases breathing rate
Decreases breathing
Dilates pupils
Constricts pupils
Inhibits digestion
Stimulates digestion
Inhibits saliva production
Stimulates saliva
production
Fight or flight
• Parasympathetic nervous
system calms you down
after a state of stress
• You are all in a
parasympathetic state now
• Blood pressures decreases,
pulse rate slows down,
digestion can start.
“The fight or flight response is a physiological
reaction to a stressful or threatening
situation. The ANS (autonomic nervous
system) changes from a parasympathetic
state to the physiologically aroused
(sympathetic state). This produces changes in
the body such as dilated pupils and increases
heart rate to prepare us for either fight or
flight.”
For each of the
scenarios
decide:
• Parasympath
etic or
sympathetic
nervous
system is
responsible
• What the
branch of the
nervous
system is
doing (e.g.
dilates pupils)
Answers
•
•
•
•
•
•
Sue: S, inhibits digestion
Les: S, causes increased breathing rate
Lenny: S, dilates pupils
Amadeep: S, inhibits saliva production
Mary: P, returns heart rate to normal
Jerry: P, stimulates digestion
Exam question
Mark scheme
Biopsychology Revision
What do you need to know?...
• Biopsychology
• The structure and function of sensory, relay and
motor neurons. The process of synaptic transmission,
including reference to neurotransmitters, excitation
and inhibition.
Neurons and synaptic
transmission
Biopsychology
Specification details
The structure and function of sensory, relay and motor
neurons.
The process of synaptic transmission, including reference to
neurotransmitters, excitation and inhibition.
Biopsychology Revision
What do you need to know?...
• Biopsychology
• The function of the endocrine system: glands and
hormones.
Endocrine System
The endocrine system
• The endocrine
system works
alongside the
nervous system to
control vital
functions in the
body. The endocrine
system acts more
slowly that the
nervous system but
has very widespread
and powerful
effects.
Glands & hormones
• Most hormones affect cells in several
organs or throughout the entire body,
leading to powerful responses
• E.g thyroid gland produces the hormone
thyroxine (increases heartrate)
• Also affects chemical processes taking
place in cells – affects growth rates
The endocrine system
• Various glands produce hormones
• Thyroid gland produces hormones
• Hormones are secreted into the bloodstream
and affect any cell in the body that has a
receptor for that particular hormone
• Hormones have powerful responses throughout
the body.
• Major endocrine gland = pituitary gland (located
in the brain)
• Controls release of hormones from all other
endocrine glands in the body.
Neurons
• Cells that conduct nerve impulses are called
neurons
• The things that people think and feel, say and
do are caused, one way or another, by
electrochemical events occurring within and
between the neurons that make up the
nervous system, particularly those in the brain
(80%)
Three types
of neurons
Relay Neuron
Myelin sheath…
Terminal Buttons
Nodes of ranvier
Different types of neurons
The cellular structure of all neurons is the same. There are anatomical
differences in size, depending on their function
1. Motor neuron
2. Relay
3. Sensory
(Interconnecting) neuron
neuron
Function
Carries messages
from the CNS to
effectors such as
muscles and
glands
Transfers
messages from
sensory neurons
to other
interconnecting
neurons or motor
neurons
Carries messages
from the PNS to
the brain and
spinal cord
Length of fibres
Short dendrites
and long axons
Short dendrites
and short or long
axons
Long dendrites
and short axons
Structural and functional differences
MOTOR
RELAY
SENSORY
The knee-jerk reflex
In a reflex arc, like the knee-jerk
reflex, a stimulus, such as a
hammer hitting the knee, is
detected by sense organs in the
peripheral nervous system, which
conveys a message along a sensory
neuron. The message reaches the
central nervous system where it
connects with a relay neuron. This
then transfers the message to a
motor neuron. This then carries
the message to an effector such as
a muscle, which causes the muscle
to contract and, hence, the knee to
move or jerk.
Relay neuron
Synapse between two neurons.
Synaptic tramsmission
Neurotransmitters…
• …are chemicals that are released from a
synaptic vesicle into the synapse by neurons.
• They affect the transfer of an impulse to
another nerve or muscle
• These neurotransmitters are “taken back up”
into the terminal buttons of neurons through
the process of reuptake
• Or they are broken down by an enzyme
Synaptic transmission
•
•
•
•
nerve impulse travels down an axon
nerve impulse reaches synaptic terminal
this triggers the release of neurotransmitters
the neurotransmitters are fired into the synaptic
gap
• neurotransmitter binds with receptors on the
dendrite of the adjacent neuron
• if successfully transmitted the neurotransmitter is
taken up by the post-synaptic neuron
• the message will continue to be passed in this way
via electrical impulses
How a synapse works
• A synapse
Answers
2. = C
Action Potential
An action potential occurs when a neuron sends
information down an axon, away from the cell body.
The action potential is an explosion of electrical activity
- this means that some event (a stimulus) causes the
resting potential to move forward
Excitation and inhibition
• Synaptic connections can be excitatory or
inhibitory – the difference lies in the action
of the neurotransmitter at the postsynaptic
receptor
• Excitatory - they make it more likely the next
neuron will fire (such as acetylcholine)
• Inhibitory - they make it less likely the next
neuron will fire (such as GABA)
• Normal brain function depends upon a
regulated balance between excitatory and
inhibitory influences
Synapse: The gap between the end of one neuron
and the dendrites of the next neuron.
What you need to label:
1. Direction of impulse.
2. Axon terminal
3. Synaptic vesicles
containing
neurotransmitter
4. Synaptic gap
5. Dendrite
6. Receptor site
Can you?
1. Explain what is meant by sensory, relay and motor neurons
(2 marks each)
2. With reference to neurotransmitters, explain what is meant
by both excitation and inhibition (4 marks)
3. With reference to sensory, relay and motor neurons, explain
the knee-jerk reflex (4 marks)
4. Explain the difference between excitatory or inhibitory
synaptic connections (4 marks)
•
Answer the ‘Check it’ questions on page 117