Reflexes Flashcards
The route taken by the information in a reflex is through the …
Reflex arc.
In the reflex arc, the neurones go through the…
Spinal cord or unconscious part of the brain. This will be a different route to the route taken by other conditioned reflexes, as there are pathways for different reflexes.
In the CNS…
The receptor cells detect the stimulus, triggering an electrical impulse. The sensory neurones carry the message to the relay neurones in a reflex arc, and these then carry the message to the effector. The muscle them contracts to move.
Reflexes are involuntary and rapid because…
They always take the same direct route through the reflex arc so no information is ever processed.
What reflex helps sea anemones survive?
They detect chemicals diffused from prey and this stimulates them to wave their tentacles, increasing the probability that they will catch the prey.
What reflex helps molluscs survive ? (Mussels and clams)
They are stimulated to close their shells when they detect a predator, decreasing their chances of getting eaten.
What do the eyes do to prevent damage from light?
When light, a stimulus, hits the eye, muscles in the eye contract to make the pupil smaller, letting less light into the eye.
What other reflexes do humans have?
If a person picks up a hot object, a reflex makes them drop it. By tapping under the knee, this causes a knee jerk reaction.
What reflexes do babies have?
Automatically suckling from their mothers.
Grasping when their palms are touched.
Taking steps when their feet are put on a flat surface.
Reflexes are…
Rapid, automatic responses to stimuli.
What happens at a synapse ?
At the synapse, electrical impulses trigger the release of chemical transmitters which diffuse across the synapse, carrying the electric impulse. The transmitters are then absorbed by the receptor cells. These cells have to be the right cells for the transmitters. This then triggers the motor neurone to carry the impulse.
