B10 - Human nervous system Flashcards
Define homeostasis?
Regulation of internal conditions of cells to maintain optimum conditions for functioning, this is in response to internal and external environments
Give examples of internal conditions?
Body temp
Water content
Blood sugar conc
What are receptors?
They detect internal and external changes known as stimuli, they are either nerves or hormones
What is a coordination area?
Coordinates a response of the body to the stimulus and sends out signals
What is an effector?
A muscle or gland that brings about responses to the stimulus, these responses restore optimum levels in the body
What does a sensory receptor detect?
Stimuli
What is information sent as around the body?
An electrical impulse
What are the 2 central nervous systems?
Brain and spinal cord
What neurone do the electrical impulses cross?
Motor neurone
What is a reflex action?
An automatic response e.g. when touching something hot you will pull your hand back before feeling pain
What is a reflex action used for?
Avoid danger, survive, breathing
What do reflex actions not involve?
Conscious part of your brain
What 2 neurones does a relay neurone connect?
Sensory and motor
Describe a reflex arc?
An impulse goes along the sensory neurone, passes along the relay and straight back to motor where neither impulse will be sent out
Define a neurotransmitter?
A chemical released by synapse
What is a synapse?
A junction in-between neurones which diffuses a chemical so that an impulse can cross, this part of a reflex action is slow
What is the reflex pathway?
Stimulus - sensory - CNS - relay - motor - effector - response
