The Senses Flashcards
What does the skin sense?
Contains receptors for pain, touch and temperature
Describe taste.
- Receptors for taste located in taste buds
- Four basic tastes, sweet, sour, bitter, salt
- Umami (MSG)
Describe smell.
- Root of nasal cavity has millions of receptors to detect smell
- 10,000 different smells
What are the five traditional senses?
- Touch
- Smell
- Taste
- Sight
- Hearing
How is balance detected?
By the vestibular apparatus in the inner ear.
What is the conjunctiva?
Is the membrane around the eye, it protects the eye.
What is the sclera?
A tough, white coat that holds the eye in place
What is the cornea?
Is the front, clear part of the sclera. Allows light into the eye and bends it to help focus it on the retina
What is the choroid?
Nourishes the eye and prevents internal reflection of light
What is the retina?
Is light sensitive. Contains light receptors, rods for black and white, and cones for colour vision
What conditions does cones best work in?
In bright light
What is the fovea?
The part of the retina where most images are focused.
What is the blind spot?
Where the optic nerve leaves the retina. Has no rods or cones
What is the lens?
Focuses light onto the retina.
What is the optic nerve?
Carries impulses to the brain
What is the iris?
The coloured part of the eye. It controls the amount of light entering the eye.
What is the pupil?
The black circle at the front of the eye, it lets light into the eye
What are the ciliary muscles?
They change the shape of the lens called accommodation to focus light on the retina
What do the aqueous and vitreous humours do?
They keep the eye in shape
What does the ear do?
Its the organ of hearing and balance
What does the pinna do?
Collects vibrations
What does the auditory canal do?
Carries vibrations to the eardrum
What does the eardrum do?
Carries vibrations to the middle ear
What is the ossicles?
The hammer, anvil and stirrup bones
They amplify the virbrations and pass them on to the cochlea in the inner ear
What is the Eustachian tube?
Connects the middle ear with the pharynx and equalises pressure between the middle and outer ear.
What is the cochlea?
Responsible for hearing, converts vibrations into electrical impulses that are sent to the brain along the auditory nerve.
What is the Organ of Corti?
Is in the cochlea, contains receptor cells that allow hearing
What are the main parts of the vestibular apparatus?
The semicircular canals
What is a common hearing disorder?
Glue ear
What causes glue ear?
Caused by too much sticky fluid in the middle ear
How is glue ear corrected?
Corrected by decongestants or grommets.
How many rods are there in each eye?
120 million
How many cones are there in each eye?
6 million
Where are cones mostly found?
At the fovea
Where are rods mostly found?
All over the retina
What liquid fills the vestibular apparatus?
Lymph
What happens to the pupil in low light?
It expands
What happens to the pupil in bright light?
It shrinks
Is the Eustachian tube part of the ear?
No
Which part of the brain are the impulses from the vestibular nerve sent to?
Cerebellum
What are grommets?
They are inserted into the middle ear, which allows air to enter and force fluid down into the Eustachian tube
What diagrams do you need to be able to draw?
- Vertical section of the skin
- Structure of the eye
- Structure of the middle ear
