Anatomy Flashcards
(91 cards)
1
Q
What are the bones and features of the bony orbit?
A
Orbital frontal plate Orbital ethmoid plate Optic canal Superior orbital fissure Infraorbital Supraorbital notch/foramen
2
Q
What shape is the bony orbit?
A
Pyramidal shape
3
Q
What makes up the external eyelid?
A
Orbicularis oculi
Orbital and palpebral parts
4
Q
What is the apex?
A
Where the optic canal is
5
Q
Where is the optic canal?
A
Medially placed
6
Q
Where does the vasculature pass through? ?
A
Maxillary
7
Q
What sits beneath the external layer of the eye?
A
Orbital septum
Sheet of fascia - Helps prevent infection spread
8
Q
What glands sit above and below the eye?
A
Tarsal glands
9
Q
What do tarsal glands secrete?
A
Lipids
Lacrimal fluid
10
Q
What muscle attaches to the superior tarsus?
A
Levator palpebrae superiolis
11
Q
What ligaments pull the tarsus to the side to give it its shape?
A
Lateral/medial palpebral ligament
12
Q
What covers the iris?
A
Cornea
13
Q
What is a limbus?
A
A corneoscleral junction
14
Q
What covers the sclera?
A
Conjunctiva
15
Q
What is the pink/orangey bit at the corners of the eye?
A
Lacrimal lake
16
Q
Where do tears pass into?
A
a Puncta (openings)
17
Q
What provides the eye with nourishment?
A
Conjunctival vessels
18
Q
What is the conjunctival fornix?
A
Where the conjuctiva over the lower eyelid and over the sclera meet
19
Q
What does the lacrimal gland secrete and what supplies it?
A
lacrimal fluid
CN VII parasym
20
Q
Where do tears drain to?
A
Canaliculi and lacrimal sac, down a nasolacrimal duct into the inferior meatus (nose)
21
Q
What is the coloured part of the eye?
A
The iris
22
Q
What is the pupil?
A
a hole
23
Q
What are corneal reflections?
A
Light reflections
24
Q
Does the cornea have a greater curvature?
A
Yes
25
What makes up the 2 parts of the fibrous outer layer of the eye?
Sclera - musslce attachment
| Cornea - 2/3 refractive power
26
What makes up the uvea (vascular layer of the eye)
iris - pupil diameter
ciliary body - controls iris, shape of lens and secretion of aqueous humour
Choroid - nutrition and gas exchange
27
What is refractive power?
Ability to focus light
28
What is the inner layer of the eye?
Retina
29
What is the anterior segment if the eye?
Anterior chamber is between cornea and iris, contains aqueous humour
Posterior chamber is between iris and suspensory ligaments, contains aqueous humour
30
What is the posterior segment of the eye?
behind lens, 2/3rds of eye
contains vitreous body which has vitreous humour.
Vitreous body is a common location for floaters
31
What is a clouding of the lens?
Cataract
32
Where is aqueous circulated?
Ciliary body
then posterior chamber - nourishes lens
passes through pupils
then reabsorbed into sclera venous sinus
33
What angle is involved with glaucoma?
angle between the Iris and the cornea
34
What can cause ishaemia of the retina?
Raised intra-ocular pressure
| Can be caused by increased fluid level in the eye
35
What makes up the retina?
Fundus:-
Optic disc
Macula
Fovea
36
What is the optic disc?
Point of CN 2 formation
Only point of entry/exit for vessels
Blind spot
37
What is the macula?
Greatest density of cons
38
What is the fovea?
centre of the macula
Depression, diameter of 1.5mm
area of most acute vision
39
How do you look at the back of the eye?
Fundoscopy
40
What causes monocular blindness?
Complete interruption of flow of the central artery (end artery) or vein
41
Are the optic canal and the optic disc closely anatomically related?
Yes
42
What are the layers of the retina?
Post to Anterior:
1. Photoreceptors
2. ganglion cells
3. axons of the ganglia
43
Where do the retinal veins/arteries lie in relation to the retina?
Anteriorly
44
Where do objects in the right visual field go to be processed?
Left primary visual cortext
45
Where do the vision pathways cross?
The optic chiasma
46
What is the Lateral geniculate nucleus (LGN)
Part of the visual pathway in the thalamus
47
What is the main blood supply of the eye?
Opthalmic artery branch of the internal carotid artery
48
Where does the opthalmic artery pass through?
Optic canal
49
What is the problem with the retinal artery?
It is an end artery
50
Where does the inferior opthalmic vein mainly drain into?
Superior opthalmic vein
51
Where does the orbit drain into?
Facial vein (valveless vein)
52
How many extraocular skeletal muscles are there?
7
53
What are the 4 rectus muscles?
Superior
Inferior
Medial
Lateral rectus
54
Where do the rectus muscle originate from and attach to?
Common tendinous rung to the sclera
55
What are the two oblique muscles?
Superior
| Inferior oblique
56
Where do the oblique muscles insert into?
Sclera
57
What does the levator palpebrea superioris do?
Lifts the upper eyelid
58
What innervates the lateral rectus?
CN VI Abducents
59
What innervates the superior oblique?
CN IV Trochlear
60
What innervates the other muscles of the eye?
CN III Oculomotor
61
What eye movements are along the vertical axis?
Abduction/adduction
| Direction of gaze
62
What eye movements are along the transverse axis?
elevation/depression
| direction of gaze
63
What eye movements are along the anteroposterior axis?
Introsion/extrosion
| superior pole of the eyeball
64
Where is the apex of orbit?
Medially placed
| *Different from optical axis*
65
What eye muscles don't have secondary movements?
Medial and lateral rectus
66
Where do the secondary movements occur?
From the primary position
67
How do you check the nerve supply of the eye?
Do eye movements one by one
68
What does the lateral rectus do?
Abduct the eyeball only
| - CN VI - abducents
69
What does the superior rectus do?
elevate the eyeball only when the eyeball is abducted
| CN III - oculomotor
70
What does the inferior rectus do?
Depress the eye when the they eye is in abduction
| CN III - oculomotor
71
What does the medial rectus do?
Adduct the eye
| CN III 0 oculomotor
72
What does the inferior oblique do?
Elevates the eyeball only when the eye is in adduction
| CN III oculomotor
73
What does the superior oblique do?
Depresses the eye only when the eye is in adduction
| CN IV trochlear
74
What gives pure elevation of the eyes?
Superior rectus and inferior oblique
| They are antagonists - act against each other to lift the eye
75
What gives pure depression?
Superior oblique and inferior rectus
| Antagonists as they work together to lower the eye
76
Where does the eyeball sit?
The suspensory ligament of the eye
77
What is diplopia?
double vision
78
Where does the suspensory ligament of the eye attach to?
Zygoma laterally
79
What can result from damage to the infraorbital canal?
General sensory deficit of the facial skin
80
Where does the zygoma rotate when fractured?
Medially towards the floor of the orbit
81
What does CN V1 supply
| (opthalmic) general sensory of skin
upper eyelid
cornea
conjuctiva
82
What does CN V2 supply? (maxillary) general sensory of skin
lower eyelid
maxila
ala of nose
83
What does CN V3 supply? (mandibular)
| general sensory of skin
mandible
temperomandibular joint
except angle of the mandible supplied by C2 C3 spinal nerves
84
What is the corneal reflex?
Blink reflex
85
What is the afferent limb of the relfex?
Sensory
86
What is the efferent limb of the reflex?
Motor
87
Where are action potentials conducted in the corneal reflex?
Centrally via CN V1 to the trigeminal ganglion then in CN V to the pons
88
Where are action potentials conducted peripherally in the corneal reflex?
In CN VII to the eyelid and orbicularis oculi
89
What does the presynaptic axon release?
Acetylcholine at the synapse
90
What does the postsynaptic axon release?
Noradrenaline at the organ to stimulate the organ
91
What cranial nerves contain presynaptic axons?
3,7,9,10
