B3.1.1 - Nervous system Flashcards
What is a stimulus?
A change in the internal or external environment
What is a receptor?
A sensory cell that detects a stimulus
What are effectors?
Muscles and glands that respond to impulses in the nervous system
What is the CNS made up of?
The brain and the spinal cord
What do the sensory neurones do?
They carry electrical impulses from receptor cells to the CNS
What do the motor neurones do?
They carry electrical impulses from the CNS to the effectors
What do the relay neurones do?
They carry electrical impulses from the sensory neurones to the motor neurones
What is the flow diagram for a nervous reaction?
Stimulus -> Receptor -> Sensory Neurone -> Spinal Cord -> Brain -> Spinal Cord -> Motor Neurone -> Effector -> Response
What is the brain protected by?
The skull
What is the spinal cord protected by?
The vertebral column
How long does a nervous reaction take?
Around 0.7 seconds
