Reflex arcs Flashcards
What is a stimulus?
A detectable change in the internal of external environment of an organism
Stimuli are detected by …
Receptors
Name the structure labelled B on the diagram
Spinal cord
A response is produced by an ….
Effector
Give two examples of an effector
Gland or muscle
Name the type of neurone ahown on the diagram
Motor neurone
Name the strucutre labelled D on the diagram
Effector (in this case a muscle)
Give the sequence of events that lead from a stimulus to a response
Stimulus –> Receptor –> Coordinator–> Effector –> Response
The simplest type of nervous response is called a …
Reflex
The central nervous system consists of …
Brain and spinal cord
What is the function of a sensory neurone?
Carry electrical impulses from receptors to central nervous system
Name the neurone labelled C on the diagram
Motor neurone
What is the function of a motor neurone?
Carry electrical impulses from central nervous system to effectors.
Why are reflexes important?
Protect from danger
Maintain posture
Give two features of a reflex arc
Immediate - only 3 neurones involved. Minimum number of synapses
Specific - one stimulus leads to one response
Involuntary - happens without conscious though
Innate - present from birth