nervous system and homeostasis Flashcards
brain
the organ of the central nervous system of mammals where vital functions are coordinated
central nervous system
the brain and the spinal cord - where reflexes and actions are coordinated
effector
a muscle or gland which responds to nervous impulses
involuntary
done without conscious control
neurones
nerve cells - they carry an electrical message or impulse when stimulated
receptors
a group of cells that are sensitive to a stimulus
reflex action
a fast, automatic response to a stimulus - they do not involve the conscious part of the brain
spinal cord
a column of nerve tissue that runs from the base of the skull down the centre of the back
stimulus
a change in the environment
synapse
the connection between two neurones
accommodation
the process of changing the shape of the lens to focus on near or distant objects
concave
curving inwards, rather than bulging outwards
convex
curving or bulging outwards, like a circle or sphere
coordination centre
an organ that processes information from receptors and organises a response from the effectors
homeostasis
the regulation of internal conditions in response to internal and external changes, to constantly maintain optimum conditions for functioning
