Synapses And Reflexes Flashcards
What is the connection between two neurones called?
Synapse
A synapse is the junction between two neurones where information is transmitted.
What are the chemicals called that transfer the nerve signal across a synapse?
Neurotransmitters
Neurotransmitters diffuse across the synaptic gap to transmit signals.
What happens after neurotransmitters diffuse across the synapse?
They set off a new electrical signal in the next neurone
This process allows the nerve impulse to continue along the neural pathway.
True or False: The transmission of a nervous impulse is faster at the synapse than along the neurones.
False
The transmission is slowed down at the synapse due to the time taken for neurotransmitters to diffuse.
What are reflexes?
Automatic, rapid responses to stimuli
Reflexes help to reduce the chances of injury by providing quick responses.
What is the term used for the passage of information in a reflex?
Reflex arc
The reflex arc describes the pathway of nerve impulses from receptor to effector.
Where do the neurones in reflex arcs go through?
The spinal cord or through an unconscious part of the brain
This allows for quick reflex actions without involving higher brain functions.
What do receptors detect in a reflex action?
Stimuli
Examples of stimuli include a bee sting or very bright light.
Fill in the blank: Impulses are sent along a ________ neurone to a relay neurone in the CNS.
Sensory
The sensory neurone carries the impulse from the receptor to the central nervous system.
What happens at the synapse between the sensory neurone and the relay neurone?
Neurotransmitters are released
This release triggers an impulse in the relay neurone.
What is the role of the motor neurone in a reflex action?
It carries impulses to the effector
The motor neurone transmits signals that result in muscle contraction or gland activity.
What is an example of an effector in a reflex action?
Muscle or gland
In the case of moving away from a bee sting, the muscle contracts.
True or False: Reflex actions involve conscious thought.
False
Reflex actions bypass conscious parts of the brain for quick responses.
What reflex protects the eye from very bright light?
Pupil constriction reflex
Bright light triggers light receptors which send signals to reduce pupil size.
What do light receptors in the eye do in response to bright light?
Send a message along a sensory neurone to the brain
This initiates a series of impulses to protect the eye.
Fill in the blank: In pupil constriction, the message travels along a relay neurone to a ________ neurone.
Motor
The motor neurone then activates the muscles in the iris.
What happens to the circular muscles in the iris when very bright light is detected?
They contract
This contraction makes the pupil smaller to protect the eye from damage.
