Chapter 33: The Nervous System Flashcards
What does the nervous system allow for?
A rapid response to stimuli in animals
What is a stimulus?
A change in the environment that triggers a response
What are the two nervous systems called?
Central nervous system
Peripheral nervous system
What does the cns involve?
Brain
Spinal cord
What does the pns involve?
Nerves outside the cns
What are the four processes in response to a stimulus?
Reception
Transmission
Integration
Response
What is reception?
Detecting the stimulus using sense organs and neutrons
What is transmission?
Message carries to and from the cns
What is integration?
Message sorted, processed and response decided in cns
What is response?
Effectors stimulated by neurons
What are effectors?
Muscles and glands
What is a neuron?
Nerve cell
What do neurons do?
Carry information as electrical impulses
What are the three types of neuron?
Sensory neuron (afferent) Motor neuron (efferent) Interneuron
What does a sensory neuron do?
Takes messages from receptors to cns
What does motor neuron do?
Takes messages from cns to effectors
What does an interneuron do?
Takes messages between sensory and motor neuron
What do dendrites do?
Fibres that carry impulses towards the cell body
What do axons do?
Carry impulse way from cell body
What does a Schwann cell do?
Make myelin sheath
What is a myelin sheath?
Membrane that insulates the electrical impulses
Speeds up the transmission of neurotransmitter
What is a cell body?
Contains nucleus and organelles
Forms dendrites, axons, neurotransmitter chemicals
What does a cell body do?
Received impulse
How can you distinguish between the motor neuron and sensory neuron?
Motor neuron - cell body is at the top
Sensory neuron - cell body is in the middle
What is a neurotransmitter swelling?
Swelling at the end of axon that releases chemicals that carry impulses from one nerve to the next
What is the gap between axons called?
Node of ranvier
What is a nerve impulse?
Movement of ions from dendrites to axon to neurotransmitter swellings
What is an ion?
A charge particle
What is a threshold?
Minimum stimulus needed for an impulse to carry