7.2 Flashcards
Nervous system
-A communication network
-Controls all other systems in the body e.g digestive and circulatory systems
-Broken into 2 parts
Central nervous system
-Includes the brain and spinal cord
-Receives and processes information before producing a response
Peripheral nervous system
-Branches out to the rest of the body
-Helps to carry information from/to the CNS
Neurons
-Nervous system is made up of trillions of nerve cells called neurons
-Transmit electrical messages called nerve impulses (travel at high speeds and only in one direction
Neuron structure
-Contains a cytoplasm, cell membrane, nucleus, dendrites, axons and axon terminals
Dendrites
-Receives messages from other nerve cells
Axons
-Sends nerve impulses away from the cell body
Axon terminal
-Helps pass the massage on to the next neuron
name the 3 types of neurons
sensory neuron, relay connector neuron, motor neuron
Sensory neuron
-Carries messages from cells in sense organs (e.g ear eyes tongue skin) to the CNS
Sensory neurons have specialised receptors that are sensitive to stimuli e.g. heat/light/sound/ taste/touch
Relay connector neuron
Transmits messages between neurons in the CNS
Motor neurons
-Carries messages from the CNS to effectors
e.g muscle glands that help transmit messages into actions
Stimuli
anything that triggers a physical or behavioral change
Transmitting between neurons
-Once the nerve impulses reach the axon terminal, special chemicals called neurotransmitters are released into the synapse (space between neurons)
-This process stimulates the dendrites of the next neuron.
action potential
Once a neuron has been stimulated, a nerve impulse travels down the axon.
This electrical signal is called an action potential
