The Senses

Eye Anatomy Sense: Vision Cornea Protective layer of the eye Iris Colored part of the eye Contains muscles to open & close the pupil Pupil Size adjusts with light Small: more light Large: less light Lens Focuses light onto the retina Retina Back of the eye Contains rods & cones

Vision Process 1) Light passes through pupil #3 #2 #1 1) Light passes through pupil 2) Lens focuses light onto retina 3) Photoreceptors (rod and cone cells) of the retina create impulses Impulse travels up optic nerve to brain

Read the color of the text Read the color of the text

Ear Anatomy Sense: Hearing Pinna Outer ear Eardrum Amplifies sound by 3 bones: malleus, incus, stapes Cochlea Contains mechanoreceptors (measures pressure)

Sound Transmission 1) Sound waves (vibration of the air) enters the ear canal 2) Eardrum & the small bones vibrate 3) Fluid in the cochlea vibrates 4) Hair cells in the cochlea bend 5) Impulse transmitted through the auditory nerve and to the brain

Sound Transition Animation

Sense: Smell & Taste Nose Tongue Scent chemicals dissolve in mucus Impulse travels from olfactory nerve to brain Tongue Chemicals dissolve in saliva Chemoreceptors in taste buds creates impulse

Sense: Touch (Temperature, Pain, Pressure) Mechanoreceptors in skin sense pressure Upper layer: gentle touches Lower layer: heavy pressure Thermoreceptors & Pain receptors detect temps and chemicals released by damaged cells Impulses sent to brain

REview Name the 5 senses. Label the diagram of the eye. Which eye part: Protects the outer eye? Contains rod and cone cells? Focuses light? Name the three bones behind the ear drum? Name the bone of the ear that has hair cells. Which sense is: related to the optic nerve? related to the olfactory nerve? related to the auditory nerve? Which receptors detect temperature changes? REview