The Nervous system Flashcards
(14 cards)
What is the nervous system?
A highway along which messages going to and from the brain travel. Nerve cells, or neurons, which form nervous tissue. Electro-chemical impulses are transmitted by neurones in the nervous tissue throughout the body. Nervous tissue have support cells, which don’t transmit signals but play a vital role in enabling neurons to do their job by sensing the environment around them so that the body can make an appropriate response.
What is the role of the nervous system?
neurones transmit electrical signals that control the function of different parts of the body, such as muscles. This happens because receptors detect a change in the environment and produce an electrical impulse in response, which is relayed through the sensory neurons to the CNS. Effectors are part of the body (such as muscles and glands) that produce a response to this stimulus.
What is the pathway that messages are passed through to create a response from the body?
Stimulus, receptor, sensory neurone, relay neurone, motor neurone, effector, response
What do sensory neurones do?
responsible for converting external stimuli from the organism’s environment into internal electrical impulses.
What do relay neurones do?
found in the brain and spinal cord and allow sensory and motor neurons to communicate. They help control muscle movements.
What do motor neurones do?
forming part of a pathway along which impulses pass from the brain or spinal cord to a muscle or gland.
What do dendrites do?
Receive messages from other cells
What are terminal branches of the axon
form junctions with other cells
What is the axon
Passes messages away from the cell body to other neurones, muscles or glands.
What is the cell body
The cells life support centre
What are neural impulses
An electrical signal travelling down the axon - action potential
What is the myelin sheath
Covers the axon of some neurones and helps speed some neural impulses
What is a reflex action
a way for the body to automatically and rapidly respond to a stimulus to minimise damage to the body
What is the reflex action process
Stimulus, receptor, sensory neurone, relay neurone, motor neurone, effector, response
