Anatomy Flashcards
Give the 3 layers of the eyeball wall
- sclera and cornea
- UVEA (choroid, iris and ciliary body)
- retina
What attaches the lens to the ciliary body?
suspensory ligaments
When is the lens relaxed?
when looking at something far away
- sympathetic, relax ciliary muscle
When is the lens tight?
When the parasympathetic brings about accomodation to look at something near
Where does light focus on the eye?
retina
Which nerve supplies tip of the nose?
opthalmic nerve which is branch v1 of CN V (trigeminal)
Give some causes of compression of cervical part of sympathetic trunk that could result in horners?
root of neck trauma carotid dissection pancoast tumour engorged internal jugular vein deep cervical lymph node mets
What covers
a) iris
b) sclera
a) cornea
b) conjunctiva
What divides the chambers of the eye?
the lens
Which angle is of importance for aqueous drainage?
iridocorneal
What is the centre of the macula?
the fovea
Where is the greatest density of cones?
macula
What are the three layers of the retina?
photoreceptors (most posterior)
ganglion cells
axons (most anterior)
Does the optic disc contain photoreceptors?
no
Name the end artery of the eye
the central retinal artery
Where do the intraocular muscles insert into?
the sclera
How do you test the abducens nerve?
with eye movements the lateral rectus does
- abduction
What eye movements can superior rectus do?
elevation (when eye is abducted)
What eye movements can inferior rectus do?
depression (when eye is abducted
How do you test the trochlear nerve?
eye movements done by superior oblique
- depression (when in adduction)
What eye movements can medial rectus do?
adduction
What eye movements can the inferior oblique do?
elevation (when in adduction)
Which muscles bring about pure elevation?
superior rectus and inferior oblique
Which muscles bring about pure depression?
superior oblique and inferior rectus
What is responsible for eye colour and pupil size changes?
iris
which fluid occupies the posterior cavity of the eye?
vitrous humour
which fluid occupies the anterior cavity of the eye?
aqueous humor
what produces aqueous humour and where does it drain to?
produced by ciliary bodies in the posterior chamber
drains via canal of schlemm
What is the outer layer of the eye like?
fibrous
What is the middle layer of the eye like?
vascular
What is the opthalmic artery a branch of?
the internal carotid artery
Which cranial nerve is the optic nerve?
CN II
What is the blind spot?
the optic disc
What is the optic disc?
point of optic nerve formation
What is the innervation of the extraocular muscles?
LR6 SO4 AO3
lateral rectus CN VI abducens
superior oblique CN IV trochlear
all others CN III oculomotor
Does the eye have more rods or cones?
rods
Where are rods found in the eye?
periphery of the eye
where are cones found in the eye?
fovea
Which photoreceptor is responsible for colour vision?
cones
Which photoreceptor is more sensitive to light?
rods
