5.1 - Nervous control Flashcards
What two subsystems does the nervous system consist of?
- The central nervous system: brain and spinal cord.
- The peripheral nervous system: pairs of nerves originating from either the brain or spinal cord.
What can the PNS be divided into?
Sensory neurones: carry nerve impulses from receptors towards the CNS.
Motor neurones: carry nerve impulses away from the CNS towards effectors.
How can the motor neurone system be divided up?
- Voluntary nervous system: carries nerve impulses to bodily muscles. Voluntary.
- Autonomic nervous system: carries nerve impulses to glands, smooth muscle, cardiac muscle. Involuntary.
What is the spinal cord?
A column of nervous tissue running along the back that lies inside the vertebral column for protection.
What emerges at intervals along the spinal cord?
Pairs of nerves.
What is a reflex?
An involuntary response to a sensory stimulus.
What is a reflex arc?
The pathway of neurones involved in a reflex.
How many neurones does the reflex arc involve? State them.
3.
What is the first stage of a reflex arc?
The stimulus.
What is the second stage of a reflex arc?
Receptor.
Once the stimuli is received it creates a nerve impulse.
What is the third stage of a reflex arc?
Sensory neurone.
Passes the nerve impulse to the spinal cord.
What is the fourth stage of a reflex arc?
Intermediate neurone.
Links the sensory neurone to the motor neurone in the spinal cord.
What is the fifth stage of a reflex arc?
Motor neurone.
Carries the nerve impulse from the spinal cord to an effector.
What is the sixth stage of a reflex arc?
Effector.
The muscle contracts.
What is the last stage of a reflex arc?
Response.
