What does the Nervous System enable humans to do?
React to their surroundings and to coordinate their behaviour
Alert them to pain and when to make reflex actions
Information from passes along cells () as impulses to the central nervous system (the or ). The brain coordinates the .
The cerebral cortex is concerned with consciousness, co-ordination and unconscious activities.
The cerebellum is concerned mainly with the coordination of muscular activity.
The medulla is concerned with unconscious activities such as heartbeat and breathing.
Scientists have been able to map regions of the brain to paticular fuctions by studying patients with brain damage, ❌ different parts of the brain and using ❌ scanning techniques.
Reflex Relay( Reflex, Relay ) actions are automatic quick unconscious( automatic, quick, unconscious ) and rapid. They often involve sensory impulse( sensory, impulse ), relay reflex pain( relay, reflex, pain ) and motor movement( motor, movement ) neurones.
In a simple reflex action such as pain-withdrawal reflex: (step 1)
impulses from a receptor pass along a sensory neurone to the CNS
impulses from an stimulus pass along pain neurones to the CNS
Reflex actions step 2:
at a synapse between a sensory neurone and a relay neurone in the CNS, a chemical is released that causes an impulse to be sent along a relay neurone
at a synapse between a relay neurone and a motor neurone in the CNS, chemical energyl is released that causes an impulse to be sent along a motor neurone
Simple reflex action part 3:
a chemical is then released at the synapse between a relay neurone an motor neurone in the central nervous system, causing impulses to be sent along a motor neurone to the effector
Simple reflex action part 4:
the effector is either a muscle or a gland: a muscle responds by contracting and a gland responds by secreting chemical substances
the effector is either a nerve or a gland: a nerve responds by sending impulses to the brain and a gland responds by secreting chemical substances
Effector include muscles and glands.