Homeostasis and Response Flashcards
what is homeostasis ?
maintaining a stable internal environment
why do are internal conditions need to be kept the same?
cells and enzymes require specific conditions to function
what make up the automatic control system?
- receptors
- coordination centre
- effector
what do multi cellular organisms do that single-celled organisms do?
multi cellular organisms have cells that communicate
what do the receptors do ?
detect stimuli
what do the effectors do?
respond to the impulses
what connects two neurones ?
synapse
what are reflexes?
rapid and automatic responses that don’t involve the conscious part of the brain
what is the path a impulse travels for a response?
- STIMULUS
- SENSORY NEUTRON
- SYNAPSE ( between sensory and relay)
- RELAY
- MOTOR NEURON
- EFFECTOR ( eg. muscle )
what is the investigation for reaction time ?
ruler 2 people
what is a more precise way of measuring reaction time ?
computer test
- reduces human errror
what is the cerebral cortex for?
- outer wrinkly bit
- consciousness
- memory
what is the medulla?
- unconscious activity
what is the cerebellum ?
muscle coordination
how can scientist study the brain?
- MRI scan
- electrically stimulating the brain
- studying patience with brain damage
what are the consequences of the electrical stimulation on the brain?
can increase problems with brain function and physical damage
what is the sclera ?
tough and supporting wall of the eye
what is the cornea ?
transparent outer layer
what is the iris ?
muscles that controls how much light goes into the eye
what is the lens ?
focuses light onto the retina
what controls the shape of the lens ?
- CILIARY MUSCLES
- SUSPENSORY LIGAMENTS
what is the optic nerve ?
carries impulses from the receptor on the retina to the brain
what happens to the eye when there is too much light?
- pupil smaller
- circular muscles contract
- radial muscles relax
how does the eye focus light on the retina ?
CHANGING the shape of the LENS
how does the eye focus on objects near to it ?
- ciliary muscles contract
- suspensory ligaments slacken
- lens becomes fatter
what can be used to treat vision defects?
contact lens
laser eye surgery
replacement lens surgery