Nervous System Flashcards
Explain what happens in the body when you touch a very very hot object.
the receptor detects to the outside stimulus (heat)
the receptor transmites electrical signals to the sensory neurone
sensory then to the central nervous system (brain)
sensory to relay
the to the motor neurone
and then onto the effector ( muscles in your hand)
muscles in your hand contract causing the hand to move away
go and label parts of an eye
search in google: unlabelled annotation of eye diagram igcse, after u finish get answers
what is sclera
white protecctive outer layer of the eye
cornea
transparent area of sclera at the front of the eyeball that lets light into the eye. Its curved surface changes the direction of light
what is iris
it is the coloured, muscular part that contracts and relaxes to change the size of the pupil (to control the amount of light reaching the retina)
what is pupil
hole in the middle of the iris which allows light to enter the eye
what is the lens
clear disc where light passes through to the retina, it focuses the light onto the retina
what is the choroid
dark layer underneath the sclera - contains many pigment cells as well as blood vessels - the pigment is there to stop the light being reflected around inside the eye
what is retina
inner-most layer at the back of the eye. this contains photoreceptors (photo=light - so photoreceptors are receptors sensitive to light). these photoreceptors (cone and rod cells) send information to the brain along sensory neurons in the optic nerve)
how does the eye focus light
cilliary muscles contract so that the suspensory ligaments are loosen, the lens is pulled thicker and more curved thus focusing light on to the retina more stronger by refracting the light
what is accomodation
the ability of the eye to focus light depending on the distance of the object
the dilation and constriction of the pupil in response to light is a ……… action
reflex action
what is normal body temperature
37 degrees
where is the thermoregulatory centre
the thermoregulatory centre is in the hypothalamus of your brain
what are thermoreceptors
receptors which detect heat and send impulses to the TRC
