Biology Flashcards
Central nervous system
the part of the nervous system composed of the brain and spinal cord
Peripheral nervous system
made up of sensory and motor neurons. It connects the central nervous system to the rest of the body, and detects and responds to change.
Neurons
Nerve cell consisting of a cell body, axon and dendrites.
Neurotransmitters
Chemical releases from the axon terminals into the synapse between your nerve cells during a nerve impulse .
Reflex arc
A nervous pathway involving g a small number of neurons. A reflex occurs when nervous impulses travel from the receptor to the spinal cord and then to the effector organ.
Conscious response
Actions taken after the brain receives information from one of the sense organs
Homeostasis
The maintenance of a relatively constant internal environment of the body or part of the body.
Stimulus response model
Stimulus receptor control centre effector response
The model occurs when messages in the form of nerve impulses are sent to the control centre after a stimulus has been detected by a receptor.The message is then interpreted and the relevant response is sent to the effector.
Nervous system
The system of nerves and nerve centres in which messages are sent as an electrical impulses and then a chemical impulse. It comprises of a central nervous system and a peripheral nervous system.
Sensory neurons
a nerve cell in the sense organs. It detects change in the environment and sends a message to the central nervous system.
Interneuron
A nerve cell that carries nervous impulses through the nervous system. They provide the link between sensory and motor neurons.
Motor neurons
The nerve cells that is sent away from the control centre and causes an organ such as a muscle or gland to respond to a stimulus.
How do messages travel though neurons.
Neurons are made up of three main parts: the cell body, dendrites and an axon. The electrical impulse enters the neuron through the dendrite which then sends in to through the cell body and the axon. When it reaches the end of the axon neurotransmitters are released into the synapse between it and another neuron. The chemical message from the neurotransmitters then binds to receptors on the dendrites of then other neuron where the chemical message may be converted into an electrical impulse. This continues until the message reaches a motor neuron which then communicates the message to an effector causing a response.
Synapse
The gap between adjoining neurons across which electrical nervous impulses are sent after they receive messages from other neurons.
Dendrites
Dendrites are structures that relay information towards the cell body for neuron after receiving messages from another neuron.