The Nervous System Flashcards
Nerves
What neurones bundle into it by connective tissue
Peripheral nervous system
Consists of nerves (bundles of neurons) that reach into the muscles and tissue in the body
Connects CNS to rest of the body
Central nervous system
Consists of the brain and spinal cord
How do neurones communicate with each other over synapses?
With chemicals called neurotransmitters
What are the 3 features of a reflex arcs?
Responses that don’t have to be learnt
Used for basic survival functions
Rapid
What are Reflexes?
Rapid and automatic responses to stimuli in the environment that don’t require input from the brain
Why don’t reflex arcs have to be learnt?
Because they are genetically encoded
What basic survival functions do reflex arcs serve?
Reducing damage
Homeostasis
Escape from predators
Why are reflex arcs rapid?
Involuntary because they don’t require conscious thought
Controlled by an arc with few synapses because chemical transmission between synapses is slow
What is the cause of a reflex?
Stimuli in the environment that requires a rapid response eg burning
In a reflex, what detects the stimulus?
Receptor cell in a receptor nerve in the skin
How is information of the stimulus sent throughout the nervous system?
Via nerve impulses
What neuron sends nerve impulses to the spinal cord region?
sensory neuron
How are the impulses transported across the spinal cord?
Via relay neurons
Where are impulses directed to after the relay neuron?
The motor neuron
