The Senses Flashcards
What are the five senses?
Touch
Taste
Smell
Sight
Hearing
How do the senses work?
Based on receptor cells
What stimuli does the skin react to?
Touch and temperature
What are receptors for taste?
Taste buds
What are the four basic taste receptors ?
Sweet, salty, sour and bitter
What is special about nose smell receptors?
They are extremely sensitive and adjust quickly to a smell and stop responding
What is the conjunctiva?
Membrane around the eye. Protects the eye
What is the sclera ?
Tough, white coat that holds the eye in shape
What is the cornea?
The front part of the sclera. It allows light into the eye and bends it to help focus on the retina
What is the choroid?
Nourishes the eye and prevents internal reflection of light, nourished by blood vessels
What is the retina?
Light sensitive. Contains light receptors, rods (black and white vision) and cones (colour vision)
What is the fovea/yellow spot?
Part of the retina where images are focused
What is the blind spot?
Where the optic nerve leaves the retina. It has no comes or rods = zero vision
What is the function of the optic nerve?
Carries impulses to the brain
What is the function of the lens?
Focuses light on the retina
What is the function of the ciliary muscle?
Changes the shape of the lens
What is the function of the iris?
Coloured part of the eye. Controls amount of light entering the eye.
What is the function of the pupil?
Black circle at the front of the eye. Lets light into the eye
What is the function of the aqueous humor?
Keeps the eye in shape
What is the function of the vitreous humor?
Keeps the eye in shape
What is the function of the external muscle?
The eye is moved by six external muscles
What are features of cones?
- 6 million (each eye)
- Detect colour
- Work in bright light only
- Mostly found in the fovea
What are features of rods?
- 120 million (each eye)
- Detect black and white
- Work in dim light only
- Found all over retina
What does bright light do to the eyes?
Reduces pupil size to reduce too much light entering the eye
What does dim light do to the eyes?
Increases pupil size to allow as much light as possible to enter the eye
What is a sight disorder and a corrective measure for it?
- Short sighted
- Can’t see distant objects
- Laser eye surgery
What lens is needed for short sighted?
Concave lens
What lens is needed for long sighted?
Convex lens
What are the main functions of the ear?
Hearing and balance
What are the three sections of the ear?
Outer, middle and inner ear
What fluid fills the inner ear?
Lymph
What causes sound?
Vibrations in the air
What is the function of the pinna?
Collects vibrations
What is the function of the auditory canal?
Carries vibrations to the eardrum
What is the function of the eardrum?
Carries vibrations to the middle ear
What are the ossicles?
Hammer, anvil and stirrup
What is the function of the ossicles?
Amplify the vibrations and pass them on top the oval window
What is the function of the Eustachian tube?
Equalises pressure between the middle and outer ear
What is the function of the cochlea?
Converts vibrations into electrical impulses that are sent to the brain along the auditory nerve
What detects balance in the ear?
The vestibular apparatus
What does the vestibular apparatus consist of?
Three semicircular canals
What is the vestibular apparatus filled with?
Lymph
What is an ear disorder and it’s corrective measure?
- Glue ear
- Too much sticky fluid in the middle ear
- Grommets
