Biopsychology- Nervous Flashcards
What is the definition of the nervous system?
Network of cells that carry messages to and from the brain/spinal cord to different parts of the body, helping all parts of the body to communicate
What is the central nervous system?
Made up of the brain and spinal cord and has 2 main functions. The brain receives information from the body’s sensory receptors and sends messages to the muscles and the glands
What is the spinal cord?
Bundle of nerve fibres enclosed within the spinal column which connects all the parts of the body with the brain.
Consists of 31 pairs of spinal nerves which are divided into 2 roots: one root contains sensory neurones which enables the transmission of sensory information to the brain.
Second toot contains Motor neurones which are involved in the transmission of Motor signals to skeletal muscles
What is the peripheral nervous system?
Nerve cells leading to and from the CNS which connects the CNS with the body and the outside world.
Consists of the somatic and autonomic system
What is the somatic nervous system?
Controls voluntary movement which carries sensory information to and from the CNS
It’s made up of cranial and spinal nerves which both have sensory and motor neurone. The sensory neurones relay information to the CNS and motor neurones relay information from the CNS to other body parts.
What is the autonomic nervous system?
Governs involuntary activities of non skeletal muscles.
Consists of the sympathetic and parasympathetic systems
What is the sympathetic system?
Produces arousal which enables us to respond quickly and efficiently
This then increases heart rate and releases glucose into the blood stream
What is the parasympathetic system?
Reduced around and conserves energy which returns the body to a state of normality.
This then decreases the heart rate and stores glucose
What is the function of the spinal cord?
Runs from the base of the brain down to the coccyx which relays information between the brain and the body
Enables the brain to regulate and monitor internal bodily processes
Enables us to perform simple reflexes without direct involvement eg: moving your hand away when you touch something hot
What are the 4 main areas of the brain?
Cerebrum, cerebellum, diencephalon and the brain stem
What is the cerebrum divided into?
Frontal lobe- which is involved in thought speech production and learning
Parietal lobe- processes sensory information such as touch and pain
Occipital lobe- processes visual information
Temporal lobe-involved with hearing and memory
What is the diencephalon?
Situated on top of the brain stem and contains 2 important structures:
The thalamus acts as a relay station for nerve impulses from the coming senses. It involves several functions eg sleep.
The hypothalamus- regulates body temperature and acts as alone between the CNS And the endocrine system
What is the brain stem?
Responsible for regulating automatic functions which are essential for life
Consists of motor and sensory neurones which travel through the brain stem allowing for impulses to pas between the brain and spinal cord
What is the cerebellum?
Sits beneath the back of the cerebrum and involved in controlling motor skills and coordinating muscles
What are neurones?
The cells making up the nervous system which conducts electrical impulses
What is the structure of a neurone?
Consists of:
Dendrites- receive signals from other neurones to sensory receptors
Cell body- which controls the centre of the neuron
Axon- conducts nerve impulses away from the cell body and towards other neurones
How much percent do neurones make up of the brain?
10%
What is the function of the sensory neurone?
Carries sensory information from the body’s sensory receptors such as skin and tongue and sensory organs such as eyes and ears to the CNS.
Carry information to the spinal cord and the brain to then convert information from the sensory receptors to neural impulses.
These impulses travel to the brain where they are translated into sensations so we can respond appropriately.
However some sensory information only travels as far as the spinal cord before the information is conveyed to motor neurones through relay neurones which allows for reflex actions to occur
What is the function of the motor neurone?
Carry motor commands from the CNS to skeletal muscles or glands which allows the control of movement.
Motor neurones are located in the CNS, they form the synapses with muscles and control their contractions.
When stimulates neurotransmitters are released to bind to receptors on the muscle and trigger a response which results in muscle movement to relax muscles
What is the function of relay neurones?
Neurones within the CNS that interconnect with different parts of the CNS allowing for sensory and motor neurones to communicate with each other.
The function if to carry signals between sensory and motor neurones and other relay neurones
What is another word for sensory neurones?
Afferent
What is another word for Motor neurones?
Efferent
What is action potential?
When neurones transmit information from one neurone to the other.
Begins with the dendrites which receive information from sensory receptors.
Information then travels across the cell body and then along the axon terminal towards other neurones.
What does synaptic transmission do?
The process by which a nerve impulse passes across the synaptic cleft from the pre synaptic neurone to the post synaptic neurone
What is the synapse?
Small gap between neurones in which neurotransmitters are released, permitting nerve impulses to be transmitted between neurones which include:
End of the presumptive neurone
Membrane of the postsynaptic neurone
Synaptic cleft gap
What are neurotransmitters?
Chemical substances that transmit nerve impulses across a synapse
What is the process of synaptic transmission?
Synaptic vesicles which contain neurotransmitters are stored at the end of the axon.
Action potential travels down the axon to the axon terminal Which then stimulates vesicles to release neurotransmitters into the synapse
The neurotransmitters diffuse across the gap over to the postsynaptic membrane to bind to specialised receptors which are then activated by that particular neurotransmitter
The process produces either excitatory or inhibitory effects on the postsynaptic neurone
What happens after synaptic transmission?
Neurotransmitters is released back into the synaptic space and then cleared from the synaptic cleft through:
Diffusion- neurotransmitters drift away
Break down-neurotransmitter broken down by enzymes
Re-uptake- some neurotransmitters are taken back up into the pre synaptic neurone and stored for later release. The quicker the reuptake the shorter the effects on the postsynaptic neurone.
What is meant by excitatory neurones?
Makes it more likely to fire
Increases neural activation in the CNS
Example:noradrenaline
What happens when an excitatory neurotransmitter binds with a postsynaptic receptor?
Causes an electrical change in the cell membrane which results in an excitatory postsynaptic potential which makes it more likely to fire
What is an inhibitory neurotransmitter?
Makes it less likely to fire as it decreases the neural activation in the CNS having a calming effect in the mind and body.
Example: GABA
