Central Nervous System - CNS - 2.12B - 2.14

Issues with treating problems in the CNS X3

1) it is hard to repair damage - nerurons don't repair theselves and scientists haven't figure out a way to repair nervous tissue in the CNS

2) problems could occur in part of the CNS that are not easy to access and therefore are hard to treat - it is not possible to remove tumours that are growing in certain parts of the brain

3) treatment for problems in the nervous system can cause permanent damage - treating the spinal cord with surgery on the spine can damage the spinal cord further

The CNS coordinates a response

(Sally, reads, such, cunty, magasines, even, roleplays)

Stimulus, receptor, sensory neuron, CNS, motor neuron, efffector, response

1) a stimulus is detected by a sensory receptor

2) when a stimulus is detected by a receptor the information is converted to a nervous electrical impulse and sent along sensory neurons to the CNS

3) the CNS coordinates the response (decided what to do about the stimulus and tells something to do it) impulses travel through the CNS along relay neurons

4) CNS send information to an effector (muscle or gland) along a motor neuron

5) the effector then responds - muscle may contract & gland may secret hormone

6) time taken to respond is reaction time

What do all neurons contain

Cell body with a nucleus & cytoplasm & other subcellular structures

What do cell bodies have?

Extensions that connect to other neurons - dendrites and dendrons

What do dendrites and dendrons do

Carry nerve impulses toward the cell body

What do axons do

carry nerve impulses away from the cell body