Biopsychology
The nervous system
Autonomic nervous system = governs brain’s involuntary activities (e.g. stress, heartbeat) and is self
regulating (divided into 2 - sympathetic and parasympathetic)
Brian = the part of the CNS which is responsible for coordinating sensation, intellectual and nervous
activity
Central nervous system (CNS) = made up of brain + spinal cord and receives info from senses & controls
body’s responses
Peripheral nervous system (PNS) = the part of the nervous system that is outside the brain and spinal
cord
Somatic nervous system = part if the PNS responsible for carrying sensory & motor info to and from CNS
Spinal cord = bundle of nerve fibres enclosed within spinal column and connects nearly all parts of body
with brian
Thalamus = acts as relay station for nerve impulses coming from senses & routes them to parts of brain
where they are processes
Hypothalamus = regulates body temp, hunger, thirst & controls the release of hormones from pituitary
gland
Central nervous system
● Consists of brain and spinal cord
● Roles - Control behaviour & regulate the body’s physiological processes
● Brain receives info from sensory receptors (e.g. eyes) & sends messages to the muscles +
glands (involves the spinal cord + nerve cells)
Spinal cord:
● Main function = relay info between brain & rest of body
● Allows brain to monitor, regulate bodily processes (e.g. breathing) + coordinate voluntary
movements
● Spinal cord connected to different parts of the body by spinal nerves (which connect muscles &
glands)
● Contains nerve cells that allow us to perform simple reflexes (e.g. pulling hand away from hot
object)
Brain:
● 4 main areas - cerebrum, cerebellum, diencephalon, brain stem
, ● Cerebrum = largest part - divided up into 4 different lobes, each with different function (e.g. frontal
lobe - involved with through + speech), split down the middle in 2 halves called cerebral
hemispheres, each hemisphere specialised for particular behaviour
● Cerebellum - controls motor skills + balance + coordinating muscles
● Diencephalon - contains thalamus + hypothalamus
Peripheral nervous system
● Transmits messages via millions of neurons (nerve cells) to and from the CNS
● Divided into somatic & autonomic nervous systems
● Consists of the somatic and autonomic nervous system
Somatic nervous system (voluntary):
● Responsible for carrying sensory and motor info to and from spinal cord
● Made up of 12 pairs of cranial nerves and 31 pairs of spinal nerves (these nerves have both
sensory + motor neurons)
● Involved in the reflex actions without the involvement of the CNS (so allows reflex to occur very
quickly)
Autonomic nervous system (involuntary):
● Governs vital functions in the body (e.g. breathing, heart rate, digestion)
● 2 main divisions of autonomic nervous system - sympathetic + parasympathetic (their actions are
mostly antagonistic - work usefully in opposition to each other, antagonistically)
● E.g. sympathetic increases heart rate & parasympathetic reduces heart rate
● E.g. sympathetic stimulates urination & parasympathetic inhibits urination
● Sympathetic nervous system (SNS)
- Involved in responses that help us to deal with emergencies, prepare body for rapid
action (fight or flight)
- E.g. increases heart rate
● Parasympathetic nervous system (PNS)
- Relaxes body when emergency has passed / calms body back down
- E.g. reduces heart rate & blood pressure
Neurons and synaptic transmission
Motor neurons = form synapses with muscles & control their contractions
Relay neuron = allow sensory and motor neurons to communicate with each other (most common type of
neuron in the CNS)
Sensory neuron = carry nerve impulses from sensory receptors to spinal cord + brain
Neurotransmitter = chemical substances that play an important role in the workings of the nervous system
by transmitting nerve impulses across the synapse
Synapse = conjunction of end of an axon of one neuron & dendrite or cell body of another
, Synaptic transmission = the process by which a nerve impulses passes across the synaptic cleft from one
neuron to another
● Neurons are cells that are specialised to carry neural info throughout the body
● 3 types
● Dendrites at end of one neuron receive signal from another neuron or sensory receptors, impulse
carried along axon, terminates at the axon terminal
Structure + function of neurons
Sensory:
● Carry nerve impulse from sensory receptors (e.g. receptors for taste or vision) to spinal cord &
brain
● Convert info from sensory receptors into neural impulses
● When the impulse reach the brian they get translated into sensations (e.g. pain) so the organism
can react
● Some terminate at the spinal cord to allow reflex actions to happen quickly without delay of going
to the brain
Relay:
● Between sensory & motor (shortest neuron)
● Allow sensory and motor neurons to communicate with each other
● Lie within the brain & spinal cord
Moter:
● Located in PNS but axons outside PNS
● Form synapses with muscles & control their contractions
● When stimulated the motor neuron releases neurotransmitters that bind to receptors on the
muscle & trigger a response, causing muscle movement
● Strength of contraction depends on rate axon is fired
● Muscle relaxation caused by inhibition of motor neuron
Synaptic transmission
Synapse = end of presynaptic neuron, membrane of postsynaptic neuron + gap in between
Synaptic gap = physical gap between pre + postsynaptic cell membranes
Synaptic vesicles = contain the neurotransmitters
Neurotransmitter = chemical substances that transmit nerve impulses across the synapse
Exocytosis = neurotransmitters released from synaptic vesicles
● Impulses need to be passed from one neuron to another
● Do this by crossing the synapse (gap between presynaptic & postsynaptic neuron)
● The synaptic vesicles contain the neurotransmitters & when impulse reaches it the
neurotransmitters are released (= exocytosis)
● Neurotransmitters diffuse across gap & binds to specialist receptors on surface of cell that
recognises it and is activated by the specific neurotransmitter
● Receptor molecules either produce excitatory or inhibitory effects on postsynaptic neuron
● Process is called synaptic transmission
Re-uptake:
The nervous system
Autonomic nervous system = governs brain’s involuntary activities (e.g. stress, heartbeat) and is self
regulating (divided into 2 - sympathetic and parasympathetic)
Brian = the part of the CNS which is responsible for coordinating sensation, intellectual and nervous
activity
Central nervous system (CNS) = made up of brain + spinal cord and receives info from senses & controls
body’s responses
Peripheral nervous system (PNS) = the part of the nervous system that is outside the brain and spinal
cord
Somatic nervous system = part if the PNS responsible for carrying sensory & motor info to and from CNS
Spinal cord = bundle of nerve fibres enclosed within spinal column and connects nearly all parts of body
with brian
Thalamus = acts as relay station for nerve impulses coming from senses & routes them to parts of brain
where they are processes
Hypothalamus = regulates body temp, hunger, thirst & controls the release of hormones from pituitary
gland
Central nervous system
● Consists of brain and spinal cord
● Roles - Control behaviour & regulate the body’s physiological processes
● Brain receives info from sensory receptors (e.g. eyes) & sends messages to the muscles +
glands (involves the spinal cord + nerve cells)
Spinal cord:
● Main function = relay info between brain & rest of body
● Allows brain to monitor, regulate bodily processes (e.g. breathing) + coordinate voluntary
movements
● Spinal cord connected to different parts of the body by spinal nerves (which connect muscles &
glands)
● Contains nerve cells that allow us to perform simple reflexes (e.g. pulling hand away from hot
object)
Brain:
● 4 main areas - cerebrum, cerebellum, diencephalon, brain stem
, ● Cerebrum = largest part - divided up into 4 different lobes, each with different function (e.g. frontal
lobe - involved with through + speech), split down the middle in 2 halves called cerebral
hemispheres, each hemisphere specialised for particular behaviour
● Cerebellum - controls motor skills + balance + coordinating muscles
● Diencephalon - contains thalamus + hypothalamus
Peripheral nervous system
● Transmits messages via millions of neurons (nerve cells) to and from the CNS
● Divided into somatic & autonomic nervous systems
● Consists of the somatic and autonomic nervous system
Somatic nervous system (voluntary):
● Responsible for carrying sensory and motor info to and from spinal cord
● Made up of 12 pairs of cranial nerves and 31 pairs of spinal nerves (these nerves have both
sensory + motor neurons)
● Involved in the reflex actions without the involvement of the CNS (so allows reflex to occur very
quickly)
Autonomic nervous system (involuntary):
● Governs vital functions in the body (e.g. breathing, heart rate, digestion)
● 2 main divisions of autonomic nervous system - sympathetic + parasympathetic (their actions are
mostly antagonistic - work usefully in opposition to each other, antagonistically)
● E.g. sympathetic increases heart rate & parasympathetic reduces heart rate
● E.g. sympathetic stimulates urination & parasympathetic inhibits urination
● Sympathetic nervous system (SNS)
- Involved in responses that help us to deal with emergencies, prepare body for rapid
action (fight or flight)
- E.g. increases heart rate
● Parasympathetic nervous system (PNS)
- Relaxes body when emergency has passed / calms body back down
- E.g. reduces heart rate & blood pressure
Neurons and synaptic transmission
Motor neurons = form synapses with muscles & control their contractions
Relay neuron = allow sensory and motor neurons to communicate with each other (most common type of
neuron in the CNS)
Sensory neuron = carry nerve impulses from sensory receptors to spinal cord + brain
Neurotransmitter = chemical substances that play an important role in the workings of the nervous system
by transmitting nerve impulses across the synapse
Synapse = conjunction of end of an axon of one neuron & dendrite or cell body of another
, Synaptic transmission = the process by which a nerve impulses passes across the synaptic cleft from one
neuron to another
● Neurons are cells that are specialised to carry neural info throughout the body
● 3 types
● Dendrites at end of one neuron receive signal from another neuron or sensory receptors, impulse
carried along axon, terminates at the axon terminal
Structure + function of neurons
Sensory:
● Carry nerve impulse from sensory receptors (e.g. receptors for taste or vision) to spinal cord &
brain
● Convert info from sensory receptors into neural impulses
● When the impulse reach the brian they get translated into sensations (e.g. pain) so the organism
can react
● Some terminate at the spinal cord to allow reflex actions to happen quickly without delay of going
to the brain
Relay:
● Between sensory & motor (shortest neuron)
● Allow sensory and motor neurons to communicate with each other
● Lie within the brain & spinal cord
Moter:
● Located in PNS but axons outside PNS
● Form synapses with muscles & control their contractions
● When stimulated the motor neuron releases neurotransmitters that bind to receptors on the
muscle & trigger a response, causing muscle movement
● Strength of contraction depends on rate axon is fired
● Muscle relaxation caused by inhibition of motor neuron
Synaptic transmission
Synapse = end of presynaptic neuron, membrane of postsynaptic neuron + gap in between
Synaptic gap = physical gap between pre + postsynaptic cell membranes
Synaptic vesicles = contain the neurotransmitters
Neurotransmitter = chemical substances that transmit nerve impulses across the synapse
Exocytosis = neurotransmitters released from synaptic vesicles
● Impulses need to be passed from one neuron to another
● Do this by crossing the synapse (gap between presynaptic & postsynaptic neuron)
● The synaptic vesicles contain the neurotransmitters & when impulse reaches it the
neurotransmitters are released (= exocytosis)
● Neurotransmitters diffuse across gap & binds to specialist receptors on surface of cell that
recognises it and is activated by the specific neurotransmitter
● Receptor molecules either produce excitatory or inhibitory effects on postsynaptic neuron
● Process is called synaptic transmission
Re-uptake:
