Anatomy Flashcards
What are the 3 parts of the retina that are important to know? (all part of the fundus)
Wee brief description too please xx
Optic disc
- forms the ‘blind spot’
- no photoreceptors
- ONLY point of entry/exit for retinal arteries/veins
Macula
- lateral to optic disc
- greatest density of optic cones
Fovea
- area of most acute vision
- small depression in centre of macula
Where is the lacrimal gland located?
Superolaterally
What is the purpose of lacrimal fluid?
Where does lacrimal fluid drain into?
Provides the cornea with O2
Inferior lacrimal papilla + punctum (wee hole that lacrimal fluid drains into)
What divides the anterior and posterior segment of the eye?
Lens
Name the three layers of the eye from outermost to innermost?
Fibrous
Uvea
Retina
What is the name given for the area in which the iris meets the sclera?
Limbus
What artery supplies the majority of the eye?
What is it a branch of?
Ophthalmic artery
Internal carotid artery
What end artery supplies the retina?
How does it travel to the retina?
Central artery of the retina
Along with the central vein of the retina in the centre of the optic nerve (CN VII)
What are the 2 veins responsible for drainage of the eye?
Where do they lead back into?
Superior ophthalmic vein
Inferior ophthalmic vein
Cavernous sinus
Where do the oculomotor muscles attach to?
What layer of the eye is this found in?
Sclera
Fibrous
What is the purpose of the choroid?
Provides nutrition and gas exchange
Absorb light
What part of the eye produces aqueous humour?
Where is this found?
What is the purpose of aqueous humour?
Ciliary process within the ciliary body
Thickened area anteriorly at same level as choroid
Alongside the lens
To nourish the lens and cornea
What is the name of the jelly-like substance that makes up 2/3rds of the eye?
What segment of the eye is it found in?
Give 3 functions of it
Vitreous humour (part of vitreous body)
Posterior segment
- Scatters light
- Hold retina in place
- Support lens
Are the suspensory ligaments found in the anterior or posterior segment of the eye?
Posterior
Do the retinal arteries and veins lie anterior or posterior to the retina?
Anterior to retina
Describe the route of aqueous humour
Produced by ciliary process
Travels in posterior chamber to lens
Through the pupil into anterior chamber and nourishes the cornea
Drains through trabecular meshwork -> Canal of Schlemm (scleral venous sinus) at iridocorneal angle
How do you remember the innervation of the extraocular muscles?
LR6
SO4
AO3
What is the origin and insertion of all rectus muscles?
Origin - common tendinous ring
Insert - sclera
What is the origin and insertion of all the oblique muscles?
Superior oblique - sphenoid bone
Inferior oblique - orbital plate of maxilla
Insert - sclera
What is the extra ocular muscle that isn’t rectus or oblique?
What is the purpose of this muscle?
Where does it insert?
Levator palpebrae superioris
Elevating upper eyelid
Superior eyelid
Why is it important that the gaze of the eye and the plane of the muscle lineup when testing clinically?
Allows to isolate the muscle alone
What muscle is tested when you get patient to:
- Abduct (look out)
- Adduct (look in)
Abduction - lateral rectus
Adduction - medial rectus
How do you isolate:
- superior rectus
- inferior rectus
SR - look out and up
IR - look out and down
What muscles are you testing when you get patient to:
- “look in and up”
- “look in and down”
Look in and up = inferior oblique
Look in and down = superior oblique
Pure elevation and depression is when the eye looks directly up/down. What two muscles cancel out rotation in order to achieve pure:
- elevation
- depression
Pure elevation
- SR
- IO
Pure depression
- IR
- SO
Where does the sympathetic innervation leave the spinal cord?
T1-L2
Where does sympathetic innervation leading to head and neck synapse?
Describe the route from here to the orbit
Superior cervical sympathetic ganglion
Enter internal and external carotid nerves
Travel with internal and external carotid arteries
Travel with the ophthalmic artery as sympathetic axons into the orbit
How does parasympathetic axons leave the CNS?
Via cranial nerves III, VII, IX, X and via sacral spinal nerves
What nerve is responsible for the parasympathetic innervation of the ciliary body?
CN III
Oculomotor nerve passes through the cavernous sinus. True or false?
True
What bone does the orbital canal come through?
Sphenoid bone
What muscle surrounds the orbit?
Orbicularis oculi
What is the medical name for upper and lower eyelid?
Superior tarsus
Inferior tarsus
What prevents spread of infection between superficial and deep parts of the orbit?
Orbital septum
What ligament is found medial and lateral to the eye?
Medial palpebral ligament
Lateral palpebral ligament
What is the name of the glands found in the eyelid?
Tarsal glands - Meibomian glands
What layer of epithelium found in the eye is more superficial, pigmented epi or non-pigmented epi?
Pigmented epi
Between the sclera and the conjunctiva what can be found?
A thin vascular sheet - episclera
