(Module 10)The Human Nervous System Flashcards
What is homeostasis
Homeostasis is the regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes
What conditions are managed by homeostasis
Water levels (w) Blood glucose levels (b) Body temperature (bt)
What is a receptor
Something which detect changes in the environment
What is a stimulus
A change/problem in the environment
E.g a hot plate when you put your hand on it
What are the three key features needed for a functioning control system in a body
Receptors - a cell which detects changes in the internal or external environment (a stimulus)
Coordination centres - areas that receive and process information from the receptors, and then send out responses
E.g the brain, the spinal cord, the pancreas
Effectors - muscles or glands that respond to the stimulus that has been recieved
How is the message sent when a stimulus appears
What is sent and where it is sent
An ELECTRICAL IMPULSE is sent through the NEURONES, which have gaps called SYNAPSES which makes sure the message is sent one way
What is a synapse and what does it do
It is a gap between nerve cells (neurones) which makes sure the message is only sent one way (e.g to the brain)
Describe the pathway of a regular electrical impulse
Stimulus (e.g hot plate)
Receptor (e.g your skin)
Sensory neurone (the electrical impulse passes through)
Central nerve system (e.g brain or spinal cord)
Motor neurone (the electrical impulse passes through on the way back with a response)
Effector (e.g muscle/gland)
Response
What are the CNS’S of the body
CNS =Central nerve system
The brain and the spinal cord
What is a reflex action
Reflex actions are automatic and rapid responses that do not require your conscience or your brain to do
E.g breathing
What is a relay neurone?
This is a nerve cell which connects the sensory neurone and the motor neurone. Generally found in the CNS
Speeds up the movement of the action
Describe the pathway of a reflex electrical impulse
Stimulus (e.g hot plate) Receptor (e.g your skin) Sensory neurone (the electrical impulse passes through) Central nerve system (the spinal cord) Relay neurone Motor neurone (the electrical impulse passes through on the way back with a response) Effector (e.g muscle/gland) Response
How does a synapse work
*The gap between nerve cells
The message can leap the gap.
When the electrical impulse gets to the end of a nerve cell, and releases a chemical
The diffusion of the chemical across the synapse is slower than the electrical impulse, but stops the impulse crossing the gap between them
The chemical attaches to the receptor on the next neurone, and the impulse continues
