Biology Nervous System Topic- Key Knowledge Flashcards
What does the central nervous system consist of?
Brain and Spinal Cord
What is an effector?
Muscle or hormonal gland
How does an eye focus on far objects?
The lens becomes less rounded, ciliary muscles relax, suspensory ligaments tighten
How does the eye focus on near objects?
Lens is rounded, ciliary muscles contract, suspensory ligaments slacken
What is a stimulus?
A change in the environment
What is a receptor?
Detects the stimulus and stimulates electrical impulses
What is the role of the sensory neurone?
To carry the electrical impulse from the receptor to the coordinator
What is a neurotransmitter?
A chemical that diffuses across a synapse (gap between two neurones) to pass the message onto the next neurone
What is the role of the relay neurone?
To connect the sensory neurone and motor neurone.
What is the role of the motor neurone?
To carry the electrical impulse from the coordinator to the effector.
What happens to the eye in dark environments?
Circular muscles relax and radial muscles contract, the pupil dilates
What happens to the eye in bright environments?
The circular muscles contract and the radial muscles relax, the pupil constrics
Where is the cell body on a sensory neurone?
To the side of the axon
Where is the cell body on a motor neurone?
At the end of the axon
