Topic 2- The Nervous System Flashcards
What is the CNS made up of?
The brain and the spinal cord
What is the CNS?
The central nervous system
What are the nerves role in the CNS?
They connect all of the body to the CNS
What are nerves made up of?
Specialised cells called neurones
Describe the axon
Shape and function
Very long and thin
Section that the information travels along
What are dendrites?
They are on the cell body
They are the points where one nerve cell connects to another
What do nerves do?
Carry messages to and from the CNS
What form are these messages?
Electrical impulses
How does a message travel from one neurone to the next?
It has to cross the synapse
What is the synapse?
A small gap between neurones
How does the message get across the synapse?
The neurone releases a chemical signal which is picked up by the next neurone
What do sensory nerves do?
Carry information from the sense organs
What happens to the information gained by the sensory organ?
It is stores in the CNS
What carries the information from the CNS?
Motor nerves
Where do the motor nerves carry the information?
To the muscles and glands
Describe the CNS process
The CNS receives information from all of the sense organs via sensory nerves about the body and the environment. The CNS sorts this information and stores some of it.
When the body needs to do something the CNS sends out information along the motor nerves to muscles and other parts of the body to make a response
Describe a reflex arc
- The stimulus from the environment is detected by a sense organ
- The sense organ sends a message through the sensory neurone to the relay neurone in the CNS
- The CNS processes the message and sends a message along the motor neurone
- The motor nerve sends the message to the muscle to give a response
What 3 words describe a reflex arc?
Rapid
Automatic
Involuntary
Why do humans have reflex actions?
To protect the body from harm and maintain the body’s position
Does a reflex action need the brain and why?
No because it is not conscious thought
What does the cerebrum do?
Controls learning, memory, personality, reasoning and controls conscious reactions/movements
What does the medulla do?
Controls the rate of breathing and heart rate
What does the cerebellum do?
Controls balance and muscular co ordination
