B10(Human Nervous System) Flashcards
What is a stimulus
A change in the environment
What’s parts make up the the central nervous system
-Brain
-Spinal cord
What’s the function of CNS
-Make quick, short term reactions to the environment
-coordinate behaviour
What are receptors
Organs containing specialised cells that enable us to detect changes in the environment
What is the impulse pathway for the nervous system
Stimulus-> receptor-> neurone-> coordination centre-> neurone-> Effector-> response
What are neurones
Specialised cells that conduct electrical impulses through out the body
What are nerves
A bundle of many more fibres enclosed within a protective sheath
-nerve fibres are the long axons of neurones together with any associated tissue
What are dendrites
Thin projections that extend from the cell body to connect with other neurones allowing electrical impulses to pass from one to the other
What is the myelin sheath
The axons of most neurones are wrapped in a insulating layer
What does the sensory neurone do
Connects receptor to coordination centre
What does the motor neurone do
Connects coordination centre to effectors
What does the relay neurone do
Creates a shortcut between sensory and motor neurones for our reflexes
What are reflexes
Automatic response to stimuli
What is a reflex action
It is a rapid and automatic response of the nervous system that does not include conscious thought
What is a reflex arc
The nerve pathway followed by a reflex action
What is the reflex pathway
-receptor in skin detects a stimulus
-sensory neurone sends electrical impulses to relay neurone located in the spinal cord
-relay neurone connects the sensory neurone to the motor neurone
-motor neurone sends electrical impulses to effector which then produce a response
What is the pathway for a synapse
Electrical impulse->synaptic vesicle releases neurotransmitter-> diffusion of neurotransmitters-> receptor triggers electrical impulse-> electrical impulse
