Eyes Flashcards
1
Q
- formed above by the frontal bone,
- the lateral margin is formed by the processes of the frontal and zygomatic bones
- the inferior margin is formed by the zygomatic bone and the maxilla
- the medial margin is formed by the processes of the maxilla and the frontal bone.
A
ORBITAL MARGIN
2
Q
3 major openings within orbital cavity
A
- Optic canal
- Superior orbital fissure
- Inferior orbital fissure
3
Q
- located posteriorly in the lesser wing of the sphenoid
- it communicates with the middle cranial fossa.
- transmits the optic nerve and the ophthalmic artery
A
OPTIC CANAL
4
Q
- opening between orbital plate of frontal and greater wing of sphenoid
- located posteriorly between the greater and lesser wings of the sphenoid
- it communicates with the middle cranial fossa
- transmits the lacrimal nerve, the frontal nerve, the trochlear nerve, the oculomotor nerve (upper and lower divisions), the abducent nerve, the nasociliary nerve, and the superior ophthalmic vein.
A
SUPERIOR ORBITAL FISSURE
5
Q
- located posteriorly between the maxilla and the greater wing of the sphenoid
- it communicates with the pterygopalatine fossa
- transmits the maxillary nerve and its zygomatic branch, the inferior ophthalmic vein, and sympathetic nerves
A
INFERIOR ORBITAL FISSURES
6
Q
Structures within orbital cavity
A
- Eyeballs
- Muscles
- Nerves
- Blood vessels
- Fat
- Lacrimal apparatus
7
Q
- provides cushion to the eyes and even for muscles and rest of contents of orbital cavity
A
FAT
8
Q
- skeletal support of eyelid
- superior tarsus/ superior tarsal plate
- Inferior tarsus/ inferior tarsal plate
A
TARSAL PLATE
9
Q
- two thin, movable folds in front of the eye
- protection from injury and excessive light
- upper eyelid larger, more mobile than lower eyelid
- lower eyelid - tears
A
EYELIDS
10
Q
- where upper eyelid and lower the lower eyelid meet each other
A
MEDIAL AND LATERAL ANGLES
11
Q
- nictitating eyelid
A
THIRD EYELID
12
Q
- elliptical opening between the eyelids
A
PALPEBRAL FISSURE
13
Q
- space between upper and lower eyelid
A
VERTICAL PALPEBRAL FISSURE
14
Q
- space between medial and lateral corner of the eyes
A
HORIZONTAL PALPEBRAL FISSURE
15
Q
- corner of eyes (medial canthus, lateral canthus)
A
CANTHUS
16
Q
- superficial covering
A
SKIN
16
Q
- made up of mucous membrane (appear transparent)
- secrete mucous for lubrication of the eyes, protection to the eyes
- more superficial than sclera
- seen along scleral region
- junction between sclera and cornea
A
CONJUNCTIVA
17
Q
- sore eyes
A
CONJUNCTIVITIS
18
Q
- are short, curved hairs on the free edges of the eyelid
A
EYELASHES
19
Q
- open directly into the eyelash follicles
- sebum for lubrication to eyelash
A
GLANDS OF ZEIS (sebaceous gland)
20
Q
- modified sweat glands that open between eyelashes
- apocrine sweat gland
- empty its secretion along eyelid
- seperate with hair
A
GLANDS OF MOLL (ciliary glands)
21
Q
- long, modified sebaceous glands that pour oily secretion onto the margin of the lid
- openings lie behind the eyelashes
- prevents overflow of tears and makes the close eyelids airtight.
- no hair follicle
- mebum
- along tarsal plate providing structural support to eyelid
A
MEIBOMIAN GLANDS (tarsal glands)
22
Q
- still oily, maintains moisture of the eyes
- secreted by tarsal gland
A
MEBUM
23
Q
LEVATOR PALPEBRAE
A
- movement of eyelids
- facial muscle
- antagonist
Insertion: tarsal plate of eyelid
Action: raises eyelid
24
ORBICULARIS OCULI
- movement of eyelids
- facial muscle
- antagonist
Insertion: skin of eyelid
Action: closes the eyes, depresses eyelids
25
- orbital part (larger)
- Palpebral part (smaller)
- found above the eyeball (superolateral)
- 12 ducts open from the lower surface of the gland
- small ducts connect to lacrimal canal (superior and inferior)
- punctum
- all fibers (parasympathetic and sympathetic) reach the lacrimal gland through the lacrimal nerve
Nerve supply: parasympathetic secretomotor fibers from lacrimal nucleus of facial nerve
LACRIMAL GLAND
26
Flow of tears
1. Lacrimal gland
2. Lacrimal ducts
3. Lacrimal canal through punctum
4. Nasolacrimal duct
5. Nasal cavity
27
LEVATOR PALPEBRAE SUPERIORIS
Origin: back of orbital cavity
Insertion: anterior surface and upper margin of superior tarsal plate
Nerve supply: striated muscle oculomotor nerve, smooth muscle sympathetic
Action: raises upper lid
28
RECTI MUSCLES
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Superior rectus (elevation)
Inferior rectus (depression)
Medial rectus (adduction)
Lateral rectus (abduction)
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29
OBLIQUE MUSCLES (prime movers for rotation)
Superior oblique
| Inferior oblique
30
- is embedded in orbital fat but is separated from it by the fascial sheath of the eyeball
EYEBALL
31
Three coats of the eyeball
1. Fibrous coat
2. Vascular pigmented coat
3. Nervous coat
32
- made up of a posterior opaque part, the sclera, and an anterior transparent part, the cornea
- main covering of the eyes
FIBROUS COAT
33
- composed of dense fibrous tissue and is white
| - is directly continuous in front with the cornea at the corneoscleral junction, or limbus.
SCLERA
34
- transparent
- largely responsible for the refraction of the light entering the eye
- in contact posteriorly with the aqueous humor
CORNEA
35
- junction between cornea and sclera
CORNEAL LIMBUS OR CORNEOSCLERAL JUNCTION
36
- consists, from behind forward, of the choroid, the ciliary body, and the iris
VASCULAR PIGMENTED COAT
37
- composed of an outer pigmented layer and an inner, highly vascular layer
CHOROID
38
- is continuous posteriorly with the choroid, and anteriorly it lies behind the peripheral margin of the iris
- composed of the ciliary ring, the ciliary processes, and the ciliary muscle
CILIARY BODY
39
- posterior part of the body, and its surface has shallow grooves, the ciliary striae
CILIARY RING
40
- are radially arranged folds, or ridges, to the posterior surfaces of which are connected the suspensory ligaments of the lens
CILIARY PROCESSES
41
- is composed of meridianal and circular fibers of smooth muscle.
- meridianal fibers run backward from the region of the corneoscleral junction to the ciliary processes.
- circular fibers are fewer in number and lie internal to the meridianal fibers
Nerve supply: parasympathetic fibers from the oculomotor nerve.
Action: facilitate tension in the suspensory ligament
CILIARY MUSCLE
42
- iris is a thin, highly contractile, pigmented diaphragm with a central aperture, the pupil
- suspended in the aqueous humor between the cornea and the lens
- circular smooth muscle (sphincter pupillae) constricts pupil (bright)
- radial smooth muscle (dilator pupillae) dilates pupil (dark)
Nerve supply: sympathetic (dilated) and parasympathetic (constrict)
IRIS AND PUPIL
43
- consists of an outer pigmented layer and an inner nervous layer.
- outer surface: is in contact with the choroid
- inner surface: is in contact with the vitreous body
- posterior three quarters of the retina is the receptor organ.
- anterior part of the retina is nonreceptive and covers the ciliary processes and the back of the iris
NERVOUS COAT: RETINA
44
- an oval, yellowish area at the center of the posterior part of the retina
- area for the most distinct vision
MACULA LUTEA
45
- a central depression of the macula lutea
FOVEA CENTRALIS
46
- a protein found in macula lutea
LUTEIN
47
- is slightly depressed at its center, where it is pierced by the central artery of the retina.
- a complete absence of rods and cones so that it is insensitive to light and is referred to as the “blind spot.”
OPTIC DISC
48
Contents of the eyeball
1. Refractive media
2. Aqueous humor
3. Vitreous body
4. Lens
49
- is a clear fluid that fills the anterior and posterior chambers of the eyeball
- a secretion from the ciliary processes, from which it enters the posterior chamber
- it then flows into the anterior chamber through the pupil and is drained away through the spaces at the iridocorneal angle into the canal of Schlemm
- support the wall of the eyeball by exerting internal pressure and thus maintaining its optical shape
- it also nourishes the cornea and the lens and removes the products of metabolism; these functions are important because the cornea and the lens do not possess a blood supply.
AQUEOUS HUMOR
50
- obstruction to the draining of the aqueous humor results in a rise in intraocular pressure
GLAUCOMA
51
- fills the eyeball behind the lens and is a transparent gel
- is to contribute slightly to the magnifying power of the eye
- it supports the posterior surface of the lens and assists in holding the neural part of the retina against the pigmented part of the retina
VITREOUS BODY
52
- is a transparent, biconvex structure enclosed in a transparent capsule
- is situated behind the iris and in front of the vitreous body and is encircled by the ciliary processes
- an elastic capsule, which envelops the structure;
- a cuboidal epithelium, which is confined to the anterior surface of the lens;
- lens fibers, which are formed from the cuboidal epithelium at the equator of the lens
LENS
53
- a narrow channel that runs through the vitreous body from the optic disc to the posterior surface of the lens
- in the fetus, it is filled by the hyaloid artery, which disappears before birth
HYALOID CANAL
