Chapter 1: Stimuli & Responses Flashcards
What does central nervous system consists?
Brain & Spinal Cord
Peripheral nervous system
> 12 CARNIAL NERVES connecting the brain to the sensory and internal organs
31 SPINAL NERVES connecting the spinal cord to the skeletal muscles
Function of nervous system
> detects stimuli
send information in form of impulses
produce appropriate responses
Voluntary action works
Stimulus>Affector>BRAIN>Effector>Response
Involuntary action works
Affector> Effector>Spinal cord
Involuntary action can be classified as two
- Involving medulla oblongata (heartbeat)
- Involving spinal cord( withdrawing hand when touches smtg hot
functions of eye : ciliary muscle
Muscle that changes the thickness of the eye lens through contractions and relaxations
functions of eye : eye lens
transparent and elastic convex lens which focuses light onto the retina
functions of eye : sclera
strong layer that maintains the shape of the eye and protects it
functions of eye : choroid
black layer prevents reflection
supply oxygen and nutrients to the eye
functions of eye : retina
contains photoreceptors
(> detects light
> produces nerve impulses)
functions of eye : yellow spot
part of retina that is most sensitive to light as it has many photoreceptors
functions of eye : optic nerves
nerve fibers which carry nerve impluses from the retina to the brain to be interpreted
functions of eye : blind spot
part of retina which is not sensitive to light as there are no photoreceptors and an exit point for all optic nerve fibers
functions of eye : vitreous humour
transparent jelly-like substance which maintains the shape of the eyeball and focuses light onto retina
functions of eye : conjunctiva
transparent menbrane
> protects front part of sclera
functions of eye : aqueous humour
transparent fluid
> maintains the shape of the eyeball and focuses light into the eye
functions of eye : pupil
> opening in the centre of the iris
controls the quantity of light entering the eye