Chapter 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 or external changes.
Name 3 conditions in the body that need to be controlled.
Water levels- amount of water in the body
Blood glucose concentration- levels of sugar in blood
Oxygen levels- respiration
How are internal conditions controlled?
There are automatic control centres in the body, they may involve a nervous response or a chemical response
Name 3 types of neurons
Sensory neuron
Relay neuron
Motor neuron
What is the CNS?
The CNS is the central nervous system. It consists pf the brain and the spinal cord
What is the PNS?
The PNS is the peripheral nervous system. It consists of all the other nerves in the body that branch off of the spinal cord
How do the internal control centres work?
Cells called receptors detect a change in or on the body (the change is called a stimuli)
Receptors send signals to a coordination centre (brain, spinal cord,pancreas)
A response is carried out by a muscle or a gland ( effectors)
Optimum conditions are restored
What is a stimulus?
A change in the environment of an organism is called a stimulus.
What are receptors?
A sense organ that picks up the stimuli. ( ears, eyes, nose, skin, mouth)
What does the central nervous system do?
It uses electrical impulses to enable you to react quickly to your surroundings and coordinate your behaviour.
How does the impulse move from stimuli to response in a conscious action?
Stimuli- nail Receptor-skin Sensory neurone CNS- spinal cord, brain Motor neurone Effector Response
How does the impulse move from stimuli to response in a reflex action?
Stimuli Receptor Sensory neurone Relay neurone Motor neurone Effector Response
What is a conscious action?
An action which you control through the conscious part of the brain such as choosing to kick a ball
What is a reflex action?
They are automatic and rapid, they do not involve the conscious parts of the brain.
Such as breathing
How do synapses work?
When an impulse arrives in a neurone it causes chemicals to be released in the gap between the two neurones called the synapse. The chemicals attach to the surface of the next neurone and set of a new electrical impulse.
