paper 2 - B- biopsychology Flashcards
What are the two nervous systems?
- CNS= central nervous system
-PNS= peripheral nervous system
What is the nervous system?
a specialised network of cells in the human body
What are the two main functions of the nervous system?
- to collect, respond and process info
2.to co-ordinate the working of different organs
What is the CNS made up from?
-spinal cord
-brain
definition of the brain?
-is the centre of all consciousness
-divided into two hemispheres
-passes messages to and from the brain
definition of the spinal cord?
-an extension of the brain
-responsible for reflex actions
what is the pns role?
-transmits messages via neurons to and from the cns
What is the pns divided into?
1.autonomic nervous system
=governs vital functions like breathing and heart rate
2.somatic nervous system
=controls muscle movement
what does biopsychology assume behaviour is caused by?
assumes behaviour is caused by activity in the nervous system
somatic nervous system?
=carrys sensory and motor info
=controls skeletal muscles and movement
=contains sensory and motor neurons
autonomic nervous system?
=governs internal functions eg. breathing and heart rate
=dvided into two divisions
-sympathetic nervous system= dilates pupils , accelerates heart
-parasympathetic nervous system = constricts pupils , inhibits heart
=two divisions are antagonistic
key assumptions of neurons?
-assume that behaviour is caused by activity in the nervous system
-nerve cells communicate with eachother by chemical/electrical signals
-nervous system transmits signals through neurons
What are the three types of neurons?
-motor
-sensory
-relay
What’s the function of a sensory neuron?
= carries messages from the pns (sensory receptors) to the cns
Whats the appearance of a sensory neuron?
= long dendrites
=short axon
Whats the function of a relay neuron?
=transfers messages from sensory neurons to other neurons
Whats the appearance of a relay neuron?
=short dendrites
=short axon
Whats the function of a motor neuron ?
=carries messages from the cns to the effectors (muscles/glands)
Whats the appearance of a motor neuron?
=short dendrites
=long axon
How does information (messages) travel from the sensory receptors?
1.from receptors nerve impulses are carried to the cns
2.sensory neurons covert info from the sensory receptors into neural impulses
3.impulses are transferred to the brain and are transferred into sensations so the organism can react / respond
where are relay neurons located?
-lay between the sensory input and the motor output
-lay within the brain and spinal cord
what do relay neurons allow to happen?
allow sensory and motor neurons to communicate with each other
where are motor neurons located and what do they do?
located in the cns
=they project their axons outside the cns and control muscles
=when stimulated motor neurons release neurotransmitters that bind to receptors on the muscle that trigger a response
Whats the reflex arc?
Stimulus
receptor
sensory neuron
cns
relay neuron
motor neuron
effector
response
Whats a pre-synaptic neuron?
before synapse
Whats a post-synaptic neuron?
whats a synpase?
gap between two neurons
What are neurotransmitters?
= they are chemicals released from the synaptic vesicle into the synapse that diffuse across to the next neuron
After the neurotransmitters diffuse across the synapse how do they enter the next neuron?
they are taken up by the post synaptic receptor site (the other neurons dendrites)
What can break down neurotransmitters?
enzymes
What happens when neurotransmitters bind to the receptor site?
stimulates an electrical impulse along the axon
What two effects can neurotransmitters have?
excitation
inhibition
Example of an excitation neurotransmitter?
adrenaline
=causes excitation of the post-synaptic neuron by increasing its positive charge making it more likely to fire
Examples of an inhibitory neurotransmitter?
=serotonin
=neuron becomes more negatively charged and less likely to fire
summation?
=excitatory and inhibitory influences are summed
=if the net effect on the post synaptic neuron is inhibitory the neuron would be less likely to fire
=if the net effect is excitatory the neuron is more likely to fire
What system control fight or flight?
sympathetic nervous system
whys fight or flight needed?
for survival and to protect ourselves
How does the body go into fight or flight?
- your sympathetic nervous system kicks in and you body prepares for defence or escape
2.these changes enable the body to protect itself by running or fighting
how is adrenaline released into the blood stream?
- sympathetic nervous system sends a signal to the adrenal medulla
2.this releases the hormone adrenaline
what physiological changes happen as of adrenaline?
- increased heart rate
- blood pressure increases
3.breathinf rate increases
= acute response to stress
how does the body go back to normal after adrenaline is released?
- the parasympathetic nervous system kicks in
2.this system is slow acting meaning it may take several minutes to get the body to go back to normal
