Anatomy - Special Senses Flashcards
(21 cards)
Which cranial nerves are involved in the special senses?
- Olfactory (CNI)
- Optic (CNII)
- Facial (CNVII)
- Vestibulocochlear (CNVIII)
- Glossopharyngeal (CNIX)
Which cranial nerve provides innervation for taste from anterior 2/3s of the tongue?
CNVII - facial nerve
Which cranial nerve provides Innervation for taste for posterior 1/3 of the tongue?
CNIX - glossopharyngeal
What is the sclera of the eye?
- the white, outer layer of the eye
- made of fibrous and elastic tissue
- covered by bulbar conjunctiva
- allows for contrast of eye to determine where person/animal is looking
What is the pupil of the eye?
The darkened hole at the middle of the iris.
What is the iris of the eye?
- smooth muscle structure which controls diameter of the pupil via 2 muscles - sphincter pupillae and dilator pupillae
- pupil becomes wider in the dark and smaller in lighter conditions
- size and symmetry of pupil can be an underlying sign of disease or injury
Which muscle is responsible for constriction of the pupil?
Sphincter pupillae
Which muscle is responsible for the dilation of the pupil.
Dilator pupillae.
Describe the cornea of the eye.
- avascular, so widely used in transplants as less chance of rejection
What is papilloedema?
Bulging of the optic disc due to intracranial pressures e.g. bleeding, tumours, lesions
What is keratoconus?
Thinning of the cornea resulting in a coning shape, can cause blurring and double vision of the eyes. Surgery may be required.
What might jaundice of the eye indicate?
Blood disorders or liver pathologies.
Where is aqueous humour of the eye produced and what is its function?
Ciliary bodies of anterior and posterior chambers.
- maintains pressure inside eye
- provides nutrients
- protection
Where is the vitreous chamber of the eye found?
Between the lens (anteriorly) and retina (posteriorly).
What is contained in the vitreous chamber?
Vitreous humour which is a gel like substance which contains phagocytes to remove cell debris and is mainly water with no blood vessels.
Describe the retina of the eye.
Found posteriorly, this is the light sensitive layer of tissue in the eye where the rods and cones for black, white and colour are found.
Where does the optic nerve take the impulses from the retina?
To the optic chiasm, optic tract, optic radiation and then occipital lobe
Where are tears produced?
The lacrimal gland which is found in the lateral aspect of the orbit.
List some functions of tears.
- lubricate movement
- remove debris
How are tears washed across the eye?
Lateral to media and drains in to nose - nasolacrimal canal
List the bones of the orbit (7)
- Frontal
- Palatine
- Ethmoid
- Lacrimal
- Maxilla
- Zygomatic
- Sphenoid
