Nervous System And Homeostasis Flashcards
What is the function of the nervous system?
Allows humans to react to their surroundings and to coordinate behaviour through both voluntary and involuntary actions
What is the nervous system made up of?
The central nervous system (brain and spinal cord) and a network of nerves
What is a nervous system response?
A change in environment (stimulus) is detected by receptors
Information from receptors passes along neurones (cells) to the CNS as electrical impulses
The CNS coordinates the body’s response
Effectors bring about a response
The body responds to the stimulus
What are reflex actions?
Reflex actions are automatic and rapid, they are not conscious movements
Help prevent damage to the body
What are neurones?
Carry electrical impulses around the body - relay neurones connect sensory neurones to motor neurones
What are synapses?
Gaps between neurones which allow electrical impulses in the nervous system to cross between neurones
What are the branched endings called?
Dendrites make connections with other neurones or effectors
What is the myelin sheath?
Insulates the axon, increasing the speed of electrical impulses
Where are axon terminals located?
On effectors, such as muscles or glands
How does a synapse work?
Impulse arrives in the neurone to sacs containing chemicals. Chemicals are released into the gap and attach to the surface of the next neurone to set up an electric impulse
What is the brain made from?
Billions of interconnected neurones, with different regions that carry out different functions
What is the cerebral cortex?
Outer layer of brain responsible for consciousness, intelligence, memory and language
What is the cerebellum?
At the back of the brain, coordinates muscle activity
What is the medulla oblongata?
Above the spinal cord, controls heart beat, breathing and other unconscious activities
How do neuroscientists study the brain?
MRI
Electrical stimulation of parts of the brain
Why is treatment of the brain difficult?
It is not fully understood what each part of the brain does
Drugs do not always reach the brain through its membranes
Surgery can easily cause damage