The Nervous system Flashcards
Define “CNS”
Central Nervous System (brain and spinal cord)
Define “PNS”
Peripheral Nervous System (neurones)
Define “stimulus”
A change in the environment detected by receptors e.g. light, temperature, pressure, smell
Define “receptor”
Specialised cells that detect the stimulus e.g. tongue, skin, nose, eye
Define “effector”
Muscle/gland that responds to the motor neurone to cause a change
Define “sensory neurone”
Neurone carrying electrical impulse FROM receptor to CNS
Define “motor neurone”
Neurone carrying electrical impulse FROM the CNS to effecto
Define “relay neurone”
Neurone carrying electrical impulse from one part of the CNS to another
Describe how messages are sent through the nervous system
Through neurones
What is the purpose of the CNS?
It allows humans to react to their surroundings and coordinate their behaviours
Define a reflex
Rapid, automatic response which does not use conscious part of the brain before response occurs
What does a reflex do?
Protects the body from harm
Define “synapse”
A gap or junction between two neurons
How does an impulse transfer across a synapse?
By chemical messages (Neurotransmitters)
