The Nervous System Flashcards
Ch 33
What’s stimulus?
a change in the environment, or anything causing a reaction in an organism
CNS stands for?
central nervous system
PNS stands for?
peripheral nervous system
What does CNS consist of?
brain & spinal chord
What does PNS consist of?
network of nerves (in form of nerve fibres)
What’s reception?
stimulus must be detected
What’s transmission?
the message passes along the neuron’s
Two effectors are?
muscles or glands
What’s a neuron?
is a nerve cell
What’s a sensory neuron?
transmits an impulse to the CNS
What’s a motor neuron?
transmits impulses from the CNS to a muscle or a gland
What’s integration?
the incoming messages are sorted and processed and a response decided upon
Where does integration take place?
in CNS, especially in the brain
What carries out the response and when?
effectors (muscle/gland) when they are stimulated by neuron
Whats a receptor and function?
cell or group of cells that detects a stimulus
Function of nerve endings?
connect sensory neurons to receptor cells or sense organs
What are dendrites and function?
fibres that transmit impulses towards the cell body & recieve impulses, transmitting them to CNS
towards! cell body
letter ‘a’ and carry away from cell body
What are axons function?
transmit impulses away from cell bodies/transmit impulses to an effector
What do schwann cells produce?
the myelin sheath
The myelin sheath is produced by?
schwann cells
Whats the myelin sheath and function?
its a fat-rich layer that insulates the electrical impulses
Why is myelin sheath important?
speeds up transmission of nerve impulses
Whats role of cell body? (3)
- recieves impulses
- produce neurotransmitters
- controls passage of impulses
What does cell body contain?
nucleus & cell organelles
How are axon terminals formed?
branches made by the splitting of an axon
What do axon terminals do?
carry impulse to a swelling called a neurotransmitter swelling
What do neurotransmitter swellings do?
release chemicals that carry the impulse from one nerve cell to another
What are chemicals in neurotransmitter swellings called?
neurotransmitters
Where are neurotransmitters stored?
in vesicles in the swellings
Whats a ganglion?
group of cell bodies located outside the CNS
Whats an interneuron?
