THE EYE AND THE VISUAL PATHWAYS Flashcards
The eye balls sits in the bony orbit of the skull. Using the labels below, label the bones that make up the bony orbit.
- ethmoid bone
- sphenoid bone
- lacrimal bone
- maxillary bone
- zygomatic bone
- frontal bone
1 = frontal bone
2 = sphenoid bone
3 = lacrimal bone
4 = ethmoid bone
5 = maxillary bone
6 = zygomatic bone
The eye ball is held in place by 2 ligaments, which 2 of the following are the ligaments?
1 - lateral check ligament
2 - medial check ligament
3 - controlateral check ligament
4 - inferior rectus ligament
1 - lateral check ligament
2 - medial check ligament
The eye ball is surrounded by fatty tissue to help maintain stability. What is this tissue called?
1 - periorbital fat
2 - fat pads
3 - visceral fat
4 - subcutaneous fat
1 - periorbital fat
There are 3 layers of the eye, what are they called?
1 - fibrous, inferior and nervous tunic
2 - fibrous, peripheral and nervous tunic
3 - fibrous, vascular and nervous tunic
4 - cartilaginous, vascular and nervous tunic
3 - fibrous, vascular and nervous tunic
There are 3 layers of the eye, what is the order from the front of the eye to the back of the eye, using the labels below:
vascular tunic
fibrous tunic
nervous tunic
- front = fibrous
- middle = vascular
- back = nervous
The fibrous tunic is a dense connective tissue located at the front layer of the eye. This layer has 2 parts what are they?
1 - iris and sclera
2 - sclera and cornea
3 - cornea and sclera
4 - cornea and retina
3 - cornea and sclera
- sclera = white fibrous tissue
- cornea = clear part of eye protecting interior of eye
The vascular tunic is the middle layer of the eye. This layer has 3 parts, using the labels below labels numbers 1-3:
- iris
- choroid
- ciliary body
1 - iris = coloured area, controls amount of light entering the eye.
2 - choroid = connective tissue
3 - ciliary body = produces fluid in eye and contains ciliary muscle
The nervous tunic is the back layer of the eye and contains the retina. The retina has 2 parts what are they?
1 - pigmented and macula layer
2 - pigmented and neural layer
3 - fovea and neural layer
4 - pigmented and cup layer
2 - pigmented and neural layer
- pigmented layer = regeneration, nutrition and support
- neural layer = converts signals into electric signals
The sclera forms 3/5ths of the outer layer of the eye and is part of the fibrous tunic, a tough fibrous tissue that is avascular. What are the 3 main functions of the sclera?
1 - attachments to muscles of the eyes, immunity, structural support
2 - attachments to muscles of the eyes, nutrition, structural support
3 - attachments to muscles of the eyes, blood supply, structural support
4 - attachments to muscles of the eyes, protection, structural support
4 - attachments to muscles of the eyes, protection, structural support
Essentially surrounds the eye, with a piercing at the back for cranial nerve II (optic nerve)
What is the name of the junction where the 3/5ths of the sclera and the cornea meet?
1 - cornea junction
2 - sclera junction
3 - corneal scleral junction
3 - corneal scleral junction
Tenons capsule sits over the sclera and covers the eyeball. What is its function?
1 - allows the conjunctiva to slide over the sclera
2 - allows ligaments to attach to the sclera
3 - allows light to enter into the eye
4 - all of the above
1 - allows the conjunctiva to slide over the sclera
The cornea, which is part of the fibrous tunic, a dense connective tissue that is transparent, avascular and very sensitive. The cornea makes up around 2/3rds of the outer layer of the eye. It is composed of 5 layers. using the labels below, label the image:
- Epithelial layer
- Bowman’s membrane
- Stroma
- Descemet’s membrane
- Endothelium
1 = Bowman’s membrane 2 = Epithelial layer 3 = Descemet’s membrane 4 = Endothelium 5 = Stroma
The corneal reflex, also known as the blink reflex or eyelid reflex, is an involuntary blinking of the eyelids elicited by stimulation of the cornea (such as by touching or by a foreign body). Which 2 cranial nerves are involved in this reflex?
1 - CN I and V
2 - CN III and IV
3 - CN V and VI
4 - CN V and VII
4 - CN V and VII
- Afferent (A = to go away from stimulus) branch: CN V (5) the trigeminal nerve (Ophthalmic branch) recieves input that that cornea is being touched
- Efferent (E = Effect following afferent) branch: CN VII (Facial nerve) contracts the orbicularis oculi muscle of eye to close the eye
The iris is the coloured part of the eye. The muscles of the iris.
- Circular muscles are closer to the pupil = contractors/smaller pupil
- Radial muscles surround the circular muscles and the pupil = dilators/bigger pipil
The muscles above change the size of the iris in response to light. What do these muscles do if there is too much or too little light?
- too much = circular pupil muscles contract and iris shrinks
- too little = radial (dilator) pupil muscles contract and iris grows
The iris is the coloured part of the eye. How does the iris get different colours?
1 - depends on level of melatonin
2 - depends on level of melanin
3 - depends on light exposure in first 12 weeks of life
4 - can be any of the above
2 - depends on level of melanin
- determined by genes on chromosomes generate eye colour
- more melanin = darker eyes
The eye has 3 chambers. From front to back what are they?
1 - media, posterior and vitreous (greek for glass like) chamber
2 - anterior, lateral and vitreous (greek for glass like) chamber
3 - anterior, posterior and vitreous (greek for glass like) chamber
4 - anterior, posterior and medial chamber
3 - anterior, posterior and vitreous (greek for glass like) chamber
The eye has 3 chambers. From front to back they are:
1 - anterior chamber
2 - posterior chamber
3 - vitreous (greek for glass like) chamber
What separates the anterior and posterior chambers?
1 - cornea
2 - macula
3 - iris
4 - conjunctiva
3 - iris
The middle layer of the eye is called the vascular layer, composed of the ciliary body, iris and choroid. The ciliary body, which contain ciliary muscle and the ciliary processes. Which 2 of the following are the functions of the ciliary muscles?
1 - involved in libriucating the eye
2 - contributes to changing the shape of the lens (flatter or rounder)
3 - involved in the accommodation reflex (lens thickening, pupillary constriction, and inward rotation of the eyes)
4 - involved in immunity if the eye
2 - contributes to changing the shape of the lens (flatter or rounder)
3 - involved in the accommodation reflex (lens thickening, pupillary constriction, and inward rotation of the eyes)
The middle layer of the eye is called the vascular layer, composed of the ciliary body, iris and choroid. The ciliary body, which contains ciliary muscles and the ciliary processes. The ciliary muscles contribute to changing the shape of the lens, which is involved in the accommodation reflex. What is the accommodation reflex?
- a three-part reflex
- function is to bring near objects into focus through lens thickening, pupillary constriction, and inward rotation of the eyes
- essentially its cross eyes
The middle layer of the eye is called the vascular layer, composed of the ciliary body, iris and choroid. The ciliary body contains the ciliary muscle and the ciliary processes. The ciliary processes attach to the ciliary ligaments to the ciliary muscles and the other end of the ciliary ligaments attaches to what?
1 - cornea
2 - conjunctiva
3 - lens
4 - iris
3 - lens
- hold lens in place and help it change shape
Ciliary process also secrete aqueous humor into anterior chamber (supplies nutrients to lens and cornea)
The middle layer of the eye is called the vascular layer, composed of the ciliary body, iris and choroid. The choroid (greek for membrane) is a highly vascular area. Which 2 of the following are the functions of the choroid?
1 - lubricates the posterior chamber
2 - contains blood vessels that provide nutrients and O2 to retina
3 - contains immune cells called dendrocytes as part of the eyes immunity
4 - absorbs light preventing scattered light from reaching the retina and distorting images
2 - contains blood vessels that provide nutrients and O2 to retina
4 - absorbs light preventing scattered light from reaching the retina and distorting images
Once light passes through the cornea and iris, what is the next structure it will come into contact with?
1 - conjunctiva
2 - macula
3 - fovea
4 - the biconvex (curved on both sides) lens
4 - the biconvex (curved on both sides) lens
When light passes through the cornea, iris and lens it reaches retina. There are the 4 basic layers of the retina, label them in the image below:
- photoreceptors (rods and cones)
- ganglion cells
- pigmented epithelial layer
- bipolar cells
1 - ganglion cells
2 - bipolar cells
3 - photoreceptors (rods and cones)
4 - pigmented epithelial layer
When light passes through the cornea, iris and lens it reaches retina. There are the 4 basic layers of the retina,
- ganglion cells
- bipolar cells
- photoreceptors (rods and cones)
- pigmented epithelial layer
What is the function of the pigmented epithelial layer?
1 - lubricates the posterior chamber
2 - reflects light that is not detected by the photoreceptors
3 - contains immune cells called dendrocytes as part of the eyes immunity
4 - absorbs light preventing scattered light from reaching the retina and distorting images
4 - absorbs light preventing scattered light from reaching the retina and distorting images
When light passes through the cornea, iris and lens it reaches retina. There are the 4 basic layers of the retina,
1 - ganglion cells
2 - bipolar cells
3 - photoreceptors (rods and cones)
4 - pigmented epithelial layer
There are 2 types of photoreceptors, rods and cones. Which of the cones and rods detects colour and which detects black and white?
- rods = black and white
- cones = colour: red, blue and green (depending on the colour of the rod)
When light passes through the cornea, iris and lens it reaches retina. There are the 4 basic layers of the retina,
1 - ganglion cells
2 - bipolar cells
3 - photoreceptors (rods and cones)
4 - pigmented epithelial layer
There are 2 types of photoreceptors, rods and cones. Rods detect black and white and cones detect red, blue and green (depending on the colour of the rod). Where is the highest concentration of the cones and rods located in the retina?
1 - throughou the macula
2 - fovea, part of the macula
3 - throughout the retina
4 - all of the above
2 - fovea, part of the macula
- in the fovea, part of the macula (oval shaped disc at back of the eye)
Once light has been detected by photoreceptors (cones and rods) in the retina, what neuronal cells do they synapse with?
1 - second layer of cones and rods
2 - ganglion cells
3 - pigmented epithelium cells
4 - bipolar neurons
4 - bipolar neurons
Once light has been detected by photoreceptors (cons and rods) in the retina, this information is then transmitted to bipolar neuronal cells. What do the bipolar nerve cells then synapse with?
1 - second layer of cones and rods
2 - ganglion cells
3 - pigmented epithelium cells
4 - bipolar neurons
2 - ganglion cells
- these transfer action potential to cranial nerve II (2) the optic nerve
Where is the highest visual acuity in the retina?
1 - throughou the macula
2 - fovea, part of the macula
3 - throughout the retina
4 - all of the above
2 - fovea, part of the macula
- centre of the macula
The optic disc is a round spot on the retina formed by the passage of the axons of the retinal ganglion cells, which transfer signals from the photoreceptors of the eye to the optic nerve, allowing us to see. Does the optic disc contain photoreceptors?
- no
- referred to as the blind spot
What is the main artery and vein supplying the eyes?
1 - central retinal artery and vein
2 - internal vein and artery
3 - long ciliary artery and vein
4 - opthalamic artery and vein
1 - central retinal artery and vein
There are 3 chambers in the eyes, called:
anterior
posteror
vitreous
The anterior and posterior chambers contain the same fluid, which is different to the fluid contained in the vitreous chamber. Match the fluid with the chamber?
- aqueous humor
- vitreous humor
- anterior and posterior = aqueous humor
- vitreous = vitreous humor
The fundus is the inside and back surface of the eye. Which of thr following would not typially be seen here?
1 - retina
2 - iris
3 - macula
4 - optic disc
5 - fovea
6 - blood vessels
2 - iris
When the optic nerve from the left and right eye enter the brain they cross over to the opposite side forming what?
1 - optic transversalis
2 - optic triad
3 - optic chiasm
4 - occipital cortex
3 - optic chiasm
Each eye has its own visual field. This can be divided into 2 parts
- nasal = medial view, closest to the nose
- temporal = lateral view
When the optic nerves from each eye meet at the optic chiasm, does the temporal or nasal field of view cross to the opposite side of the brain?
- temporal field of view (what we see)
- this hits the nasal retina field of view in the eye
The optic nerve developed as an out-pouching from the brain, meaning it is covered by all 3 layers of the meninges. What are the 3 layers (below), from outside in?
- pia mater
- arachnoid mater
- dura mater (periosteal and meningeal)
- most outer = dura mater (periosteal and meningeal)
- middle = arachnoid mater
- middle = pia mater
The optic nerve enters the bony skull through the optic foramen in the sphenoid bone and then travels in the optic canal of the sphenoid bone. Where does it leave the skull to reach the back of the eye?
1 - optic foramen
2 - optic chiasm
3 - foreman laciule
4 - foreman ovale
1 - optic foramen
Once the optic nerves form the optic chiasm, they then form optic tracts, which then synapse where?
1 - pretectal nucleus
2 - primary visual cortex
3 - lateral geniculate nucleus of the thalamus
4 - termoral retina
3 - lateral geniculate nucleus of the thalamus
- able to sharpen contrast and enhance depth perception
Once the optic nerves form the optic chiasm, they then form optic tracts, and synapse with the lateral geniculate nucleus of the thalamus, which is able to sharpen contrast and enhance depth perception. The lateral geniculate nucleus then form optic radiations which travel to the primary visual cortex. What area of the brain is this?
1 - temporal lobe
2 - occipital lobe
3 - frontal lobe
4 - parietal lobe
2 - occipital lobe
In the Bordmann area 17, the electrical signal is processed in form, motion and colour
The central artery and vein of the retina is the main blood vessel of the eye. What artery is this a branch of?
1 - central retinal artery and vein
2 - internal vein and artery
3 - long ciliary artery and vein
4 - opthalamic artery and vein
4 - opthalamic artery and vein
Cranial nerve II (2), the optic nerve is the main nerve contributing to visual sight. However, what other cranial nerves are involved in the eyes that control the muscles of the eyes?
1 - cranial nerve III (3) occulomotor nerves
2 - cranial nerve IV (4) trochlear (latin for pully) nerves
3 - cranial nerve VI (6) the abducens nerve
4 - all of the above
1 - cranial nerve III (3) occulomotor nerves
2 - cranial nerve IV (4) trochlear (latin for pully) nerves
3 - cranial nerve VI (6) the abducens nerve
The conjunctiva is a clear tissue covering the exposed sclera of the eye and the eye lids, held in place by the tenons fascia. There are 2 parts to the conjunctive:
- bulbar = thin, slightly vascular, surrounds eye-ball
- palpebral = - dense, highly vascular lines inner surface of lids
If these 2 layers become inflamed, what is this called?
1 - blepharitis
2 - uveitis
3 - iritis
4 - conjunctivitis
4 - conjunctivitis
The lens is composed of proteins. As we age these proteins can change and even clump together, clouding the normally clear lens of the eye. What is this called?
1 - scleritis
2 - photosensitivity
3 - glaucoma
4 - cataracts
4 - cataract
- remember by c for cataract and c for clumping proteins
Aqueous humour is a transparent water-like fluid similar to plasma, but containing low protein concentrations. It is secreted from the ciliary body, a structure supporting the lens of the eyeball from the posterior to the anterior chamber, as seen in the image below. Once into the anterior chamber it drains via the drainage angle trabecular meshwork. If this fluid does not get drained, this can increase intraoccular pressure on the eye, specifically the optic nerve, affecting our vision. What is this condition called?
1 - scleritis
2 - photosensitivity
3 - glaucoma
4 - cataracts
4 - glaucoma
- can lead to loss of vision if it’s not diagnosed and treated early
Using the labels below, label the image of the lacrimal apparatus of the eye:
- Nasolacrimal duct
- Lacrimal gland
- Lacrimal sac
- Lacrimal puncta
1 = Lacrimal gland
2 = Lacrimal puncta
3 - Lacrimal sac
4 - Nasolacrimal duct
The lacrimal apparatus of the eye is composed of the Lacrimal gland, puncta, sac and nasolacrimal duct. What is the function of the lacrimal apparatus?
1 - formation of tears
2 - circulation of tears
3 - drainage of tears
4 - all of the above
4 - all of the above
There are 6 major muscles of the eye that arise from the back of the orbit. Label them using the labels below:
- Superior rectus
- Inferior rectus
- Medial rectus
- Lateral rectus
- Inferior oblique
- Superior oblique
1 = Superior oblique (think muscles diagonally on abs and eye) 2 = Inferior oblique 3 = Lateral rectus 4 = Inferior rectus 5 = Medial rectus 6 = Superior rectus
There are 6 major muscles of the eye that arise from the back of the orbit.
Superior rectus Inferior rectus Medial rectus Lateral rectus Inferior oblique Superior oblique
These muscles are controlled by 3 cranial nerves (CN).
CN III (3) = Oculomotor CN IV (4) = Trochlear CN VI (6) = Abducens
Which CN innervate which muscles?
- CN III (3) Occulomotor = inferior obliques, inferior, superior and medial rectus
- CN IV (4) Trochlear = superior oblique
- CN VI (6) Abducens = lateral rectus (think abduct the eye ball from medial line)
Remeber SO4 and LR6
- SO4 = superior oblique CN IV
- LR6 = lateral rectus CN VI
This leaves all other muscles to CN III
There are 6 major muscles of the eye, namely:
Superior rectus
Inferior rectus
Medial rectus
Lateral rectus
Inferior oblique
Superior oblique
What movement does the superior oblique assist with?
1 - moves eye lateraly
2 - moves eye medially
3 - moves eye up and down
4 - rotates eye laterally and down
4 - rotates eye laterally and down
- does opposite to what you think
There are 6 major muscles of the eye, namely:
Superior rectus
Inferior rectus
Medial rectus
Lateral rectus
Inferior oblique
Superior oblique
What movement does the inferior oblique assist with?
1 - rotates eye laterally and up
2 - moves eye medially
3 - moves eye up and down
4 - rotates eye laterally and down
1 - rotates eye laterally and up
- does opposite to what you think
The middle layer of the eye, called the vascular layer. One part is called the ciliary body, which contain ciliary muscle and the ciliary processes. The ciliary processes attach to the ciliary ligaments to the ciliary muscles and the other end of the ciliary ligaments attaches to the lens. What happens when the ciliary muscles contract?
- ciliary ligaments relax
- relaxed ciliary ligaments causes lens to bulge and shorted
- a bulged and shorter lens is for close vision (parasympathetic)
