Control SDL: Eyes and ears Flashcards
What fluid is contained within the pupil?
Aqueous humour
What structures does light pass through before reaching the retinal photoreceptors?
Cornea
Pupil
Lens
What fluid fills the middle of the eye?
Vitreous humour
What are the three layers that run around the eye, from superficial to deep?
Sclera
Choroid
Retina
What kind of epithelium are the conjunctiva formed from?
Columnar epithelium
What are the functions of the conjunctiva?
Lubricate the eyes with mucus and tears
Contribute to immunity - physical barrier to the eye
What is the function of the sclera?
Protects the eye
What colour is the sclera and is it transparent or opaque?
White, opaque
What controls the diameter of the pupil?
Iris
What is the name of and the nerve supply to the circular muscle of the iris?
Sphincter pupillae
Short ciliary nerves
What is the name of and the nerve supply to the radial muscle of the iris?
Dilator pupillae
Long ciliary nerves
What is the nerve supply to the ciliary muscle in the ciliary body?
Short ciliary nerves
Which cranial nerve are the short ciliary nerves derived from?
III Oculomotor
Which cranial nerve are the long ciliary nerves derived from?
V1 Opthalmic division of the trigeminal
What is the function of the ciliary muscle?
Contraction causes the lens become more spherical
Is the lens more suited to long or short distance sight when they are more spherical?
Short distance
What is produced by the ciliary body
Aqueous humour
Which veins does aqueous humour drain into?
Episcleral veins
What condition is caused by the progressive death of retinal ganglion cells?
Glaucoma
What are the functions of the choroid layer?
Provides blood supply to the eye
Contains melanin to prevent uncontrolled reflection of light inside eye
What lines the posterior compartment of the eye?
Retina
Where are the photoreceptors in the eye?
Retina
What pigment is contained in the pigment layer of the retina?
Melanin
Are rods or cones responsible for colour vision?
Cones
Are rods or cones more sensitive to light?
Rods
Are rods or cones more useful for sight in dim conditions?
Rods
Are rods or cones responsible for more sharp vision?
Cones
What is the name of the blind spot of the retina?
Optic disc
What cells are the first order neurons of the visual pathway?
Bipolar cells
What cells are the second order neurons of the visual pathway?
Ganglion cells
Where do the axons of retinal ganglion cells converge?
Optic disc
What is the name for optic disc swelling?
Papilloedema
What is optic disc swelling a sign of?
Intracranial hypertension
What is the name of the point on the retina where the image of the object at the centre of the visual axis falls?
Fovea
What is the fovea at the centre of?
Macula lutea
Is the macula lutea lateral or medial to the optic disc?
Lateral
What is the fovea surrounded by?
Parafovea belt
How is the parafovea belt specialised for visual activity?
Over five layers of ganglion cells
High concentration of cone cells
Where do blood vessels in the retina radiate from?
Centre of the optic nerve/disc
What is the main artery that supplies the retina?
Central retinal artery
