Term
| Identify the 6 special senses & their components? |
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Definition
1. vision - eyes
2. hearing - ears
3. taste - tongue
4. smell - nose
5. touch, pain, temp, pressure - skin
6. position & balance - cerebellum/ears |
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Term
| Identify the components of the eye? |
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Definition
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Term
| SCLERA - Function & Structure |
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Definition
* Fibrous layer of the eye
* Forms the white area of anterior surface
* The sclera provides attachment for the intrinsic muscles of the eye.
* Is a pigmented muscular structure consisting of an inner ring of circular muscle and an outer layer of radial muscle. Its function is to help control the amount of light entering the eye so that:
- too much light does not enter the eye which would damage the retina
- enough light enters to allow a person to see |
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Term
| CORNEA - Function & Structure |
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Definition
*The cornea acts as the eye's outermost lens. It functions like a window that controls and focuses the entry of light into the eye. The cornea contributes between 65-75% of the eye's total focusing power.
* Protects the rest of the eye from germs, dust, and other harmful matter.
* Helps to maintain the shape of the anterior chamber of the eyeball |
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Term
| CHOROID - Function & Structure |
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Definition
* Layer of blood vessels located between the retina and sclera
* Provides the outer layers of the retina with oxygen and nutrients
* Is where the bundle of sensory fibres form the optic nerve; it contains no light-sensitive receptors |
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Term
| CILLARY BODY - Function & Structure |
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Definition
* Has suspensory ligaments that hold the lens in place.
* It secretes the aqueous humour, and contains ciliary muscles that enable the lens to change shape, during accommodation (focusing on near and distant objects) |
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Term
| IRIS - Function & Structure |
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Definition
* A part of the retina that is directly opposite the pupil and contains only cone cells.
* It is responsible for good visual acuity (good resolution)
* Contractile structure made up of smooth muscle
* Forms the coloured part of the eye |
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Term
| RETINA - Function & Structure |
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Definition
* Innermost layer of the eye, lining vitrious chamber; also called neural layer
* Is a transparent, jelly-like mass located behind the lens. It acts as a ‘suspension’ for the lens so that the delicate lens is not damaged. It helps to maintain the shape of the posterior chamber of the eyeball |
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Term
| MACULA LUTEA - Function & Structure |
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Definition
* Small yellowish area of the retina near the optic disk
* Provides central vision |
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Term
| CONJUNCTIVA - Function & Structure |
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Definition
* layer of stratified squamous epithelium that covers the inner surfaces of the eyelids & anterior surface of the eye to the edges of the cornea.
* Is a thin protective covering of epithelial cells. It protects the cornea against damage by friction (tears from the tear glands help this process by lubricating the surface of the conjunctiva) |
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Term
| EYELIDS - Function & Structure |
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Definition
* (Palpebrae) Continuation of skin
* Continual blinking keeps eyelid lubricated, removes dust & debris
* Can close firmly to protect the surface of the eye. |
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Term
| EXTRAOCULAR MUSCLES - Function & Structure |
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Definition
* 6 muscles that control movement of the eye
* 1 muscle that controls eyelid elevation (levator palpebrae).
* The actions of the six muscles responsible for eye movement depend on the position of the eye at the time of muscle contraction. |
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Term
| LACRIMAL APPARATUS - Function & Structure |
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Definition
| * Muscle in the face that closes the eyelids. |
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Term
| To enable an object to be seen, the light stimulus must be received by ..... of the eye? |
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Definition
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Term
| For light to come to a point focus on the retina, it must be refracted (bent) as it passes through the ......., ..........., Lens & ............ |
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Definition
Cornea
Aqueous Humour
Vitreous Humour |
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Term
| The light stimulates the rods and cones (photoreceptors) and the impulse is passed on to the occipital lobe of the .............. via the optic nerve, for interpretation. |
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Definition
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Term
| Objects 6 metres away are able to be seen with no adjustment to the structures within the .......? |
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Definition
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Term
| For near(close) vision, accommodation is necessary. This involves 3 processes, name them? |
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Definition
1. Constriction of the pupils to prevent any excess light.
2. Convergence of the eyes (turning inwards to bring the object into focus)
3. Alteration of the lens shape - it becomes more convex to allow objects to be seen clearly. |
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Term
| Age effects which type of vision, near or far? |
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Definition
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Term
| Identify structures of the ear |
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Definition
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Term
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Definition
* Consists of the pinna (visable ear) and auditory canal
* Collect & directs sound waves towards the middle ear
* The external ear consist of two portions, the first being the pinna, the skin covered flabby cartilage of the ear visible on both sides of the head. The basic function of the outer ear or pinna is to protect the eardrum (tympanic membrane). The outer ear also functions to collect sound waves to the eardrum through the ear canal.
The second component of the external ear is the auditory ear canal or meatus. There are modified sweat glands that secrete ear wax in the ear canal. If ear wax is excessive, the ear drum can be damaged or lead to blockage of the transmission of sound.
Unlike those of animals, human ears are usually of same size. They only grow from infancy up until youth. The outer ear, also called auricles, of animals vary in sizes and breeds. |
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Term
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Definition
* Begins the process of transmitting these vibrations to the inner ear
* Air filled chamber separated from the external acoustic meatus by tympanic membrane.
* Connected to pharynx by the auditory tube.
* The middle ear refers to the hollowed air-filled bony space (tympanic cavity) in the temporal bone of the skull behind the eardrum. It is just separated from the outer ear by the ear drum. There are three tiny bones (auditory ossicles) in the tympanic cavity that vibrates when exposed to sound waves, namely:
•Malleus – Also known as hammer
•Incus – Also known as anvil
•Stapes – commonly called stirrup
These bones form a chain around the middle ear and extend to the oval window of the inner ear and their main function is to amplify sound.
The middle ear connects to the back of the throat and nose through the Eustachian tube. The Eustachian tube is the auditory openings that we open when we yawn or swallow. |
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Term
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Definition
* Contains sensory organs for hearing & equilibrium
* Receives amplified sound waves from the middle ear
* The inner ear is the most complicated component of the auditory system located into a tiny space of the hardest temporal bone and inaccessible to direct examination or clinical manipulation. The inner ear comprise of three intimately related structures - the cochlea (spiral tube), three semicircular canals and the vestibule (labyrinth).
The cochlea is directly responsible for hearing and contains nerves responsible for converting energy vibrations within the inner ear fluid into nerve impulses which can be transmitted to the brain. While the vestibule (labyrinth) and semicircular canals function to maintain balance or equilibrium. |
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Term
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Definition
| External auditory canal - ear drum (tympanic membrane) vibrates |
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Term
| ......... transmit the vibratory motion from the eardrum to the oval window. |
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Definition
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Term
| Movement of oval window sets up waves in the ....... |
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Definition
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Term
| Pressure increases / decreases in the endolymph? |
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Definition
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Term
| Hair cells of the organ of corti are stimulated by ................ |
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Definition
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Term
| Impulses are transmitted along the cochlea nerve to the auditory cortex in the ....... |
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Definition
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