Senses 2.0 Flashcards
What are the three sections of the ear?
Outer Ear, Middle Ear, Inner Ear
What are the components of the Outer Ear?
Pinna, Auditory Canal, Eardrum
What is the function of the Pinna?
Collects sound and Channels vibrations from the surrounding area into the ear.
What does the Auditory Canal do?
Carries vibrations towards the eardrum.
What is the Eardrum?
A tightly stretched membrane that vibrates when stimulated by vibrations in the auditory canal.
What are the components of the Middle Ear?
Ossicles (Hammer, Anvil, Stirrup) and the Eustachian tube.
What is the function of the Ossicles?
Amplify soft sounds and dampen sounds.
How do the Ossicles work?
Vibrations from the eardrum cause them to move, passing vibrations to the oval window.
What does the Eustachian tube connect?
Connects the middle ear to the pharynx and throat.
What is the function of the Eustachian tube?
Equalises pressure at either side of the eardrum by swallowing or yawning.
What are the components of the Inner Ear?
Cochlea, Vestibular canal (Semicircular canals)
What is the Cochlea?
A spiral tube lined with cilia that converts vibrations into electrochemical impulses.
How do vibrations travel in the Cochlea?
They enter through the oval window and travel through lymph, stimulating hair cells.
What does the Vestibular apparatus consist of?
3 circular canals filled with lymph and cilia.
What is the function of the Vestibular apparatus?
Controls our balance by sending signals to the cerebellum.
How is the ear protected?
By the skull and earwax.
What part of the ear produces impulses interpreted as sound?
The cochlea.
What is a hearing disorder associated with excess fluid?
Glue ear.
Diagram of the ear
Why is there three semi circular canals
To control balance in the three planes/ dimensions
What are the 5 human senses?
Taste, Touch, Hearing, Sight, Smell.
How are our senses processed?
Sense organs contain receptor cells which detect particular stimuli. They change to electrical impulses & are sent to the brain to be processed.
What organ and stimuli are associated with touch?
Skin - Temperature, pressure + pain.
What organ and stimuli are associated with taste?
Tongue & throat lining - Dissolved chemicals.
What organ and stimuli are associated with smell?
Nose - Chemicals in gas state.
What organ and stimuli are associated with sight?
Eyes - Light.
What organ is associated with hearing?
Ear, also helps with balance - Sound waves.
What is the sclera?
The white of the eye. Acts as protection & is the place where external skeletal muscles attach to allow the eye to move.
What is the conjunctiva?
Covers the sclera & cornea for protection. Produces some mucus to prevent entry of pathogens.
What is the cornea?
Transparent section that allows light to enter.
What is the iris?
Coloured part of the eye. Smooth muscle that contracts & relaxes to control the amount of light in the eye.
What is the pupil?
Hole in the centre of the iris that allows light into the eye. Appears black as light enters & doesn’t leave.
What is the aqueous humour?
Watery liquid just inside the cornea that gives shape to the front of the eye.
What is the vitreous humour?
Viscous liquid that keeps the shape of the eyeball by causing pressure on the sclera.
What is the ciliary muscle?
Controls shape of lens, reflex action.
What is the suspensory ligament?
Helps the contraction & relaxation of ciliary muscle.
What is the lens?
Transparent structure. Changes shape to allow for accommodation. Held in place by ciliary muscle & suspensory ligaments.
What is the choroid?
Prevents internal reflection of light inside the eye. Contains blood vessels that nourish the eye.
What does the optic nerve do?
Carries impulses from rods and cones in the retina to the brain.
What is the retina?
Light sensitive structure in the eye that contains cones & rods.
What is the fovea?
Contains large amount of cones. Provides colour to vision. Vision is best in this spot
What structure contains rods & cones?
Retina.
What are rods?
Rod shaped, detect black and white light, active in dim light, located all over the retina.
What are cones?
Cone shaped, detect colours: Red, blue & green, active in bright light, located all over the fovea.
What happens to the iris in bright light?
Iris muscle contracted, reduces pupil size, less light into eye, prevents damage to retina.
What happens to the iris in dim light?
Iris muscle relaxed, pupil is relaxed, more light gets into the eye towards the choroid.
What happens to the lens when the ciliary muscle is contracted?
Lens becomes more convex, refraction of incoming rays a lot more, occurs when looking close.
What happens to the lens when the ciliary muscle is relaxed?
Lens becomes less convex (thinner), less refraction of incoming rays, occurs when looking at distant objects.
What are the benefits of having two eyes?
Two eyes allow us to see two images & so the brain receives two images and can negotiate depth.
What protects the eye?
Eyelid & eyelashes.
What is a hearing disorder associated with fluid in the middle ear?
Glue ear.
What causes glue ear?
Too much fluid collecting in the middle ear as a result of a viral infection. Experience a lot of pain & hearing loss as ossicles cannot move properly.
What are corrective measures for mild cases of glue ear?
Decongestant drugs will break down the fluid & clear the blockages. It then drains the eustachian tube.
What are corrective measures for serious cases of glue ear?
Grommets are placed in eardrums. It allows air to enter the middle ear & forces fluid down the eustachian tube.
Diagram of eye
Diagram of eye
