bio-nervous system Flashcards
what are the components of the nervous system?
Central Nervous System = brain + spinal cord
Peripheral Nervous System = receptors + nerves
What is the role of the nervous system?
Controls the body’s processes and actions (from
simple reflex actions to complex thought processes)
Co-ordinates the work of other systems of body
what are the 3 types of neurones?
sensory neurone, relay neurone, motor neurone
what does the sensory neurone do?
it transmits nerve impulses from the receptors to the central nervous system.
what does the relay neurone do?
it transmits nerve impulses from the sensory neurone to the motor neurone. It is found within the central nervous system.
what does the motor neurone do?
it transmits nerve impulses from the central nervous system to the effectors.
what happens at the synapse?
At the end of the neurone, electrical impulse
triggers the release of neurotransmitters.
Neurotransmitters diffuse across the
synapse to the next neurone, and stimulates
the neurone to generate electrical impulses.
The neurotransmitters are then inactivated
by enzymes to ensure that it does not
trigger another electrical impulse.
what happens when nerve meets muscles?
At the end of the neurone, electrical
impulse triggers the release of
neurotransmitters. Neurotransmitters diffuse to muscle cells. This stimulates the muscles to contract. Enzymes inactivate the neurotransmitters
to ensure that it does not trigger another
contraction.
what is a nerve?
A bundle of nerve fibres (neurones) enclosed in a sheath of connective tissue
what is a reflex action?
It is an immediate response to a specific stimulus
without conscious control.
what is a reflex arc?
it is the shortest pathway by which nerve impulses travel from the receptor to the effector in a reflex action.
what is a cranial reflex?
controlled by the brain, usually occurs in the head region.
what is a spinal reflex?
controlled by the spinal cord, for example, knee-jerk reflex.
what do receptors do?
they generate nerve impulses.
what happens when you touch a hot object?
1.Receptor stimulated by heat and generates nerve impulses. Sensory neurone transmits impulses to spinal cord.
2. Relay neurone transmits
impulses up the spinal cord to
brain.
3. BRAIN interprets
impulse as pain and
coordinates a response.
4. Relay neurone transmits new
impulses from brain down the spinal
cord to motor neurone.
4. Effector stimulated by impulses from motor neurone and muscle contracts. Hand moves away from hot object.
