Chapter 10 Flashcards
what is homeostasis?
the regulation of internal conditions for cells in response to internal and external changes to maintain the best functioning environment
why are enzymes so important?
they control the functioning of the cell
examples of the internal conditions controlled by homeostasis (3)
blood glucose levels
temperature
water content of the body
examples of internal changes (3)
when you get hotter after exercise
when your blood glucose level goes up after eating
when you lose water in hot weather
what are receptors?
cells that detect changes in internal or external environment
what are coordination centres and what do they do?
areas that receive and process information from the receptors. they send out signals to other parts of the body to react
what is an effector?
something that reacts to the changes to restore optimum conditions
what does the nervous system do?
sends electrical impulses around the body so you can react to your surroundings
how are electrical signals transported?
neurones
pathway that an impulse takes
receptor sensory neurone relay neurone motor neurone effector
difference between neurone and nerve
a nerve is a group of neurones
what is the CNS and what does it involve?
the central nervous system, made of brain and spinal cord
what is a reflex?
an automatic response
examples of a reflex (2)
touching something hot and moving away
something coming at your face and moving
why are reflexes so important?
help keep us safe, they happen so fast
what are the three neurones involved in a reflex arc?
sensory neurone
motor neurone
relay neurone
what do sensory neurones do?
carry impulses from organs to CNS
what do relay neurones do
connect sensory neurone and motor neurone, found in CNS
what do motor neurones do
carry information from CNS to body
describe a reflex arc
the impulse travels from receptor to sensory neurone to relay neurone in CNS to motor neurone and back to effector
what is important to remember about reflex arc?
doesnโt need brainโs input
what is a synapse?
something connecting the neurones which the impulse must travel across
what happens at the synapse?
the electrical impulse canโt cross so releases a chemical that can and this starts a new electrical impulse at the next neurone
why is it important reflexes donโt go to conscious area of brain?
would take too long to process
what does the cerebral cortex do?
consciousness, intelligence, memory and language