354

Sense organs

1

19

Meridians. Meridiani. Semicircles oriented at

1

In the narrow sense, the organs of vision, hear-

right angles to the equator between the anterior

ing, smell and taste.

and posterior poles. D.

2

2

ORGAN OF VISION. Organum visus (visuale).

20

External axis of eyeball. Axis bulbi externus.

3

EYE. Oculus.

Line connecting anterior and posterior poles. C

3

4

Optic nerve. N. opticus. Fiber bundle beginning

21

Internal axis of eyeball. Axis bulbi internus.

in the retina and extending as far as the optic

Distance from posterior surface of cornea to the

chiasm.

Histologically

and

embryologically

inner surface of retina measured along an im-

4

speaking, it is the tract of the brain that is ac-

aginary line (external axis of eyeball) through

cordingly enclosed by meninges up to the pos-

the anterior and posterior poles. C

5

terior aspect of the eyeball. Its axons have no

22

Optic axis. Axis opticus. Line passing through

neurilemma (sheath of Schwann) but are myeli-

the midline of the cornea and lens and bisecting

nated. The myelin sheath is formed by the oligo-

the retina between the fovea centralis and optic

6

dendroglia. A C E

disc. C

5

Intracranial part. Pars intracranialis. Segment

23

FIBROUS TUNIC OF EYEBALL. Tunica fibrosa

7

of the optic nerve betweeen the optic canal and

bulbi. External wall of eyeball comprising the

6

the chiasm. E

Pars

intracanicularis.

cornea and sclera. C

8

Intracanalicular part.

24

Sclera. The bluish-white outer coat of the eye-

Segment of the optic nerve located in the optic

ball, which

consists of

irregulatory arranged

canal. It is partially connected with the canal

9

collagenous fibers visible through the conjunc-

wall. E

7

part. Pars orbitalis. Slightly tortuous

tiva. A B C

Orbital

25 Scleral sulcus. Sulcus sclerae. Shallow groove

10

segment of the optic nerve measuring about

between the cornea and sclera caused by the

3 cm in length and occupying the orbit. E

greater curvature of the cornea. B C D

8 Intraocular part. Pars intraocularis. Segment of

11

26

Corneoscleral junction. Limbus. The concave

optic nerve located in the wall of the eyeball.

9

Postlaminar

part. Pars postlaminaris. In-

border of the sclera adjacent to the cornea. B

12

27 Trabecular meshwork (pectinate ligament).

traocular segment located behind the lamina

Reticulum

trabeculare

(lig. pectinatum)

cribrosa and thus at the site where the external

[[spongium

iridocorneale]]. Connective tissue

13

sheath of the optic nerve (dura) blends into the

framework at the iridocorneal (filtration) angle.

sclera. A

10

Intralaminar part. Pars intralaminaris. In-

28

Corneoscleral part. Pars corneoscleralis. Part

14

of the meshwork attached to the sclera. B

traocular segment lying within the lamina cri-

brosa. A

29

Uveal part. Pars uvealis. Part of the trabecular

15

11

Prelaminar part. Pars preliminaris. Intraocular

meshwork attached to the iris. B

segment extending between the lamina cri-

30

Canal of Schlemm. Sinus venosus sclerae.

brosa and the nerve fiber layer of the retina. A

Circular vessel occupying the interior aspect of

16

12

External sheath. Vagina externa. Dural cover-

the trabecular meshwork. It can be interrupted

ing of the optic nerve extending up to the eye-

or doubled and is involved in the discharge of

17

ball. A

aqueous humor from the anterior chamber. B

13

Internal sheath. Vagina interna. Pia and

31

Episclera. Lamina episcleralis. Delicate dis-

18

arachnoid coverings acoompanying the optic

placeable connective tissue between the outer

nerve to the eyeball. A

surface of the sclera and [[Tenon’s capsule]]

14

Intervaginal

spaces.

Spatia intervaginalia.

(bulbar fascia).

19

Subarachnoid space accompanying the optic

32

Substantia propria sclerae corneal stroma.

nerve and the capillary space between the

The proper substance, i. e., main part of the

20

arachnoid and dura. A

sclera. It consists of irregularly arranged col-

15 Eyeball. Bulbus oculis. Globe of the eye. It con-

lagenous fibers with sparse elastic fibers. A B

21

sists of the cornea and sclera together with all of

33

Lamina fusca sclerae. Layer of loose connective

the structures they enclose. D

tissue connecting the sclera and the choroid

16 Anterior pole. Polus anterior (center of anterior

lying below it. It appears yellowish owing to the

22

curvature) of the eyeball, which is determined

pigment cells dispersed within it. A

by the corneal vertex. D

34

Lamina cribrosa. Fine, perforated layer of the

23

17

Posterior pole. Polus posterior (center of poste-

slcera for the passage of optic nerve fibers from

rior curvature) of the eyeball, which lies lateral

the retina. A

24

to the exit of the optic nerve and opposite to the

anterior pole. D

356

Sense organs

1

Cornea. The transparent anterior part (1/6) of

16

Vascular lamina. Lamina vasculosa. It contains

1

the eyeball with an anterior convex curvature

the branchings of the short posterior ciliary ar-

and a posterior concave curvature. It is 0.9 mm

teries. A

2

thick in the middle, 1.2 mm thick at its margins.

17

Choriocapillaris.

Lamina

choroidocapillaris.

B D

Pigment-free layer of connective tissue with a

2 Conjunctival ring. Anulus conjunctivae. Junc-

3

dense network of capillaries extending as far as

tion between bulbar conjunctival epithelium

the ora serrata. It is often delimited from the

and the anterior epithelium of the cornea. D

vascular lamina by a special connective tissue

4

3

Corneoscleral junction. Limbus corneae. D

layer. A

4

Vertex corneae. The most prominent point on

18

Basal lamina [[Bruch’s membrane]]. Com-

5

the anterior surface of the cornea.

plexus (lamina) basalis. Homogeneous zone

5 Anterior surface. Facies anterior. Corneal sur-

about 2−4 mm thick between the choriocapil-

laris and the pigment epithelium of the retina. A

6

face facing the outside air. D

19 Ciliary body. Corpus ciliare. Enlarged uveal seg-

6 Posterior surface. Facies posterior. Corneal sur-

ment situated between the ora serrata and root

7

face facing the anterior chamber. D

of the iris. It contains ciliary muscles and

7 Anterior

epithelium. Epithelium

anterius.

processes. C

8

Stratified

(about

5 layers)

squamous

20

Pars plicata (Corona ciliaris). Circular zone oc-

epithelium covering the anterior surface of the

cupied by ciliary processes. C

cornea with a very smooth surface. B D

9

8

21

Ciliary

processes.

Processus ciliares. 70−80

Anterior

limiting

(Bowman’s)

membrane.

radially

oriented,

capillary-rich folds,

0.1−

Lamina limitans

anterior [[Bowman]]. Basal

0.2 mm wide, 1 mm high and 2−3 mm long.

10

membrane of the anterior epithelium, about

Their epithelium produces aqueous humor. C

10−20 mm thick. It is continuous posteriorly

22

Ciliary folds. Plicate ciliares. Low folds in the re-

with the substantia propria. B

11

9

Substantia propria. Predominant part of the

gion of the corona ciliaris and between the cili-

ary processes. C

avascular cornea consisting of highly organized

12

23

Pars plana. Orbiculus ciliaris. Circular zone

lamellar connective tissue embedded within a

mucopolysaccharide substance. The state of

lying between the corona and ora serrata. It is

turgescence of its fibers and the distribution of

occupied by ciliary folds. C

13

its colloidal matrix affect the transparency of

24 Ciliary muscle. M. ciliaris. Smooth muscle oc-

the cornea. B

cupying the ciliary body. It pulls the choroid for-

14

10

Posterior

limiting

(Descemet’s)

membrane.

ward and, in so doing, relaxes the zonule fibers

Lamina limitans posterior [[Descemet]]. Basal

so that the lens can become more strongly

15

membrane of the

corneal

(posterior) en-

curved for accomodation of near objects. D

dothelium. At its lateral margin it divides into

25

Meridional (longitudinal) fibers. Fibrae mer-

fibers which radiate into the trabecular mesh-

16

idionales [fibrae longitudinales]. Larger muscle

work of the sclera and iris. Aqueous humor

fibers oriented meridionally (longitudinally).

passes through its interstices to drain into the

Anteriorly they are attached to the posterior

17

sinus venosus sclerae. B D

limiting lamina above the trabecular mesh-

11

Posterior epithelium (endothelium). Epithe-

work; posteriorly, they insert into the choroid.

lium posterius. Simple squamous epithelium

D

18

lining the posterior surface of the cornea. B D

26

Circular fibers.

Fibrae

circulares. Circular

12 VASCULAR TUNIC OF EYEBALL (UVEAL TRACT).

muscle lying internal to the meridional fibers. D

19

Tunica vasculosa bulbi (tractus uvealis). It rep-

27

Radial

fibers. Fibrae radiales. Muscle

fibers

resents the middle layer of the wall of the eye-

crossing perpendicular to the two other muscle

20

ball and consists of the choroid, ciliary body and

systems and coursing outwardly.

iris.

28 Basal lamina. Lamina basalis. Continuation of

13

Choroid. Choroidea. The vascular coat lying be-

21

the basal membrane of the choroid. It supports

tween the retina and sclera. A

the epithelium. D

14 Suprachoroid lamina (lamina fusca). Lamina

22

suprachoroidea.

Displaceable

layer

directly

beneath the sclera. It contains only a few vessels

23

and pigment; its fibers are partly covered by en-

dothelium. A

24

15 Perichoroidal space. Spatium perichoroideale.

Spatial system in the suprachoroid lamina, part

of which forms lymph pathways. It houses the

25

ciliary nerves, long and short posterior ciliary

arteries and the vorticose veins. A

358

Sense organs

1

Iris. Frontally-located, round, variably colored

16

Lesser arterial circle of iris. Circulus arteriosus

1

disk about 10−12 mm in diameter, with a cen-

iridis minor. Ringlike vascular system in the vi-

tral aperture (pupil). The iris forms the poste-

cinity of the pupillary margin formed by anas-

2

rior border of the anterior chamber of the eye.

tomoses between the radial branches of the

Its lateral margins become continuous with the

greater arterial circle. A

ciliary body. A

17

Pupillary membrane. [Membrana pupillaris].

3

2

Pupillary margin. Margo pupillaris. Medial (in-

Anterior part of embryonical vascular mem-

ternal) margin of the iris bordering the pupil. A

brane around the lens that is situated behind

4

B

the pupil. It is fused to the pupillary margin and

3

Ciliary margin. Margo ciliaris. Lateral (external)

18

receives blood vessels from there.

margin of iris attached to ciliary body at the ir-

INTERNAL (SENSORY) TUNIC OF EYEBALL.

5

idocorneal angle. B

Tunica interna bulbi. It comprises the retina

4

Anterior surface. Facies anterior. It faces the

with its pigment epithelium.

6

anterior chamber. B

19

Retina. Inner lining of eyeball developed from

5

Posterior surface. Facies posterior. Surface

the two layers of the optic cup. Most of it is

7

facing the posterior chamber. A B

light-sensitive (pars optica). B

20 Pars optica retinae. Retinal segment capable of

6

Greater ring (circle) of iris. Anulus iridis major.

Ciliary segment of the iris, and outer cirucular

transforming light stimuli into nerve impulses.

8

It lines the posterior aspect of the eyeball and

zone on the anterior surface of the iris. It is

coarser and broader than the lesser ring. A

extends as far anteriorly as the ora serrata. B

9

7

Lesser ring (circle) of iris. Anulus iridis minor.

21

Pigmented part. Pars pigmentosa. Pigment

epithelium arising from the external layer of the

Pupillary segment of iris. Narrow, circular inner

zone on the anterior surface of iris. Its structure

optic cup. B

10

22

Nervous part. Pars nervosa. Retina proper con-

is finer than that of the greater ring. A

8

Iridial folds. Plicae iridis. Folds passing around

sisting essentially of three nuclear layers lying

11

the pupillary margin on the anterior side of the

internal to the pigment epithelium. B

23

Neuroepithelial (photosensitive) layer. Stratum

iris. They make the pupillary margin appear

slightly serrated. A

neuroepitheliale (photosensorium). Outer layer

12

9

Pupil. Pupilla. Aperture in the iris surrounded

of the cerebral stratum. It consists of rods and

by the pupillary margin of the iris. Its diameter

cones, the outer segments of which affect the

13

varies depending upon the intensity of light and

transformation of light stimuli into nerve im-

pulses. Cell bodies of rods and cones form the

the focal distance of the observed object. A

10

M. sphincter pupillae. Network of spirally

outermost layer of the retinal nuclei (external

14

nuclear layer). D

coursing muscle fibers the longitudinal axes of

24

Internal nuclear layer. [[Stratum ganglionare reti-

which run approximately parallel to the pupil-

15

lary margin when the pupil is dilated. It is in-

nae]]. Middle layer of cell nuclei mainly con-

sisting of the cell bodies of bipolar and amacrine

nervated by parasympathetic fibers from the

oculomotor nerve. B

cells. D

16

25

Ganglion cell layer. [[Stratum ganglionare n. op-

11

M. dilator pupillae. Thin layer of smooth

muscle mainly comprised of radially oriented

tici]]. Internal layer of nuclei consisting of multi-

17

fibers. It is innervated by sympathetic fibers

polar cell bodies of initially non-myelinated

ganglion cells the axons of which form the optic

from the carotid plexus.

12

Stroma iridis. Vascular framework of the iris in-

nerve. D

18

26

Ora serrata. Serrated margin between the

filtrated by pigmented connective tissue cells.

Its anterior and posterior portions are thicker

light-sensitive and light-insensitive parts of the

19

than the rest and are divided by a fine fibrous

neural retina. B C

27

Pars ciliaris retinae. Light-insensitive retinal

network. A B

13

Pigmented (posterior) epithelium. Epithelium

segment consisting of a bilayered cuboidal

20

epithelium (ciliary epithelium) forming the

pigmentosum. Bilayered epithelium on the

posterior surface of the iris. It is so heavily pig-

posterior surface of the ciliary body. Its outer

21

mented that no nuclei are visible on the surface

layer of epithelium is continuous with the pig-

ment epithelium of the retina and is pigmented,

facing the posterior chamber. A

14

Spaces of iridocorneal angle [spaces of Fon-

whereas the innermost epithelium is continu-

22

ous with the pars nervosa of the retina and is

tana]. Spatia anguli iridocornealis. Interstices

devoid of pigment. B

between the fibers of the trabecular meshwork.

28 Pars iridica retinae. Light-insensitive retinal

23

They form passageways that convey aqueous

segment on the posterior surface of the iris. It is

fluid to the sinus venosus sclerae. A

15

Greater arterial circle of iris. Circulus arterio-

continuous with the pars ciliaris retinae and

24

forms the bilayered posterior epithelium of the

sus iridis major. Ringlike vascular system with

iris. Both layers are heavily pigmented. B

radiating branches. It is formed by anastomoses

360

Sense organs

1

Optic disc (papilla). Discus nervi optici [papilla

16

1

nervi optici]. Beginning of the optic nerve as

visualized in the fundus about 3−4 mm medial

2

to the macula. It is about 1.6 mm in diameter. C

2 Physiological cup. Excavatio disci. Depression

17

3

in the middle of the optic disc with the stems of

the central retinal artery and vein. C

3 Macula [[lutea]]. Transversely oval, yellowish

4

area, 2−4 mm in diameter, at the posterior pole

of the retina. C

362

Sense organs

1

Posterior chamber. Camera posterior. It ex-

14

Lens fibers. Fibrae lentis. Fibers corresponding

1

tends from the iris and ciliary body to the ante-

to the lens epithelium from which they develop.

rior surface of the vitreous. A

They form the lens substance measuring 2.5−

2

2

Aqueous humor. Humor aquosus. Produced by

12 µm thick and up to 10 mm long. C

the ciliary processes. It flows between the in-

15

Epithelium of lens. Epithelium lentis. Part of

3

terstices of the suspensory ligaments of the lens

the lens confined to the anterior surface and ex-

to the anterior surface of the lens and then be-

tending as far as the equator. It is derived

tween the iris and lens to the pupil, through

embryologically from the anterior epithelium

4

which it enters the anterior chamber.

of the lens vesicle. C

3

Vitreous chamber. Camera vitrea. Space filled

16

Lens capsule. Capsula lentis. Transparent mem-

5

up by the vitreous body. B

brane, up to 15 µm thick, covering the lens in-

4

Vitreous body. Corpus vitreum. It consists of

cluding its epithelium. Its anterior pole is

about 98% water and primarily contains traces

thicker than the posterior pole. It gives attach-

6

of protein and NaCl and a mixture of fine fibrils

ment to the suspensory ligaments. C

which thicken near the surface to form a lim-

17

Anterior pole. Polus anterior. D

7

iting membrane. It has a gelatinous consistency

18

Posterior pole. Polus posterior. D

due to its high content of hyaluronic acid. A

19

Anterior surface. Facies anterior. Less curved

5

Hyaloid

artery. [A. hyaloidea]. Branch of the

8

ophthalmic artery supplying the vascular mem-

lens surface with a radius of 8.3−10 mm. C

20

Posterior surface. Facies posterior. More

brane of the lens. Present only during embry-

9

onic development. The proximal portion per-

curved lens surface with a radius of about

6.5 mm. C

sists in the optic nerve as the central retinal

artery. B

21

Axis. Line connecting anterior and posterior

10

6

Hyaloid canal. Canalis hyaloideus. Canal

poles. D

within the vitreous body formerly occupied by

22

Equator. Margin of lens. D

11

the embryonic hyaloid artery which degener-

23

Radii of lens. Suture line of the individual lens

ates in

this region.

The canal assumes a

fibers. In the young it resembles a triradiate

downward sagging corkscrew shape; it extends

12

seam. D

from the optic disc to the posterior surface of

24 Ciliary zonule. Zonula ciliaris. Suspensory ap-

the lens. Its wall is formed by condensed fibers.

paratus together with its interstices. It encircles

13

A

the lens equator and consists of a radially

7

Hyaloid (lenticular, patellar) fossa. Fossa hy-

oriented system of fibers of variable length and

aloidea. Fossa on the anterior surface of the vit-

14

the folds situated between them. C

reous body adjacent to the lens. A

25

Zonular fibers (suspensory ligaments). Fi-

8

Vitreous

(hyaloid)

membrane. Membrana

15

brae zonulares. Suspensory fibers attached to

vitrea. Condensation of fibers on the surface of

the equator and the adjacent anterior and post-

the vitreous body. See (4), vitreous body. A

erior surfaces of the lens. They arise distally

16

9

Stroma of vitreous body. Stroma vitreum.

from the basal lamina of the ciliary body and the

Fine network of fibers in the virtreous body. Its

pars ciliaris retinae. C

surface thickens to form the vitreous mem-

26

Zonular spaces. Spatia zonularia. Spaces be-

17

brane.

tween the zonule fibers filled with percolating

9 a Vitreous humor. Humor vitreus. Fluid part of

aqueous humor. C

364

Sense organs

1

ACCESSORY ORGANS OF EYE. Organa oculi ac-

15

Superficial lamina of levator tendon.

1

cessoria.

Lamina superficialis. It passes between the tar-

2

Muscles of eye. Musculi bulbi. Extrinsic ocular

sus and orbicularis oculi to insert into the sub-

2

cutaneous connective tissue of the upper eyelid.

muscles.

3

Orbital muscle. M. orbitalis. Thin layer of

It is so broad that it extends mainly laterally to

the wall of the orbit. A

3

smooth muscle which bridges the inferior orbi-

16

Deep lamina of levator tendon. Lamina pro-

tal fissure. C

funda. It inserts into the upper margin and the

4

Superior rectus. M. rectus superior. o: Common

4

anterior surface of the tarsus. A

tendinous ring. i: Along an oblique line in front

17

Orbital fasciae. Fasciae orbitales.

5

of the equator, 7−8 mm posterior to the corneal

18

Periosteum of orbit. Periorbita. It is delicate

margin. A: Elevation and medial rotation of su-

perior pole of eyeball. I: Oculomotor nerve. B C

and fused solidly to the bone at the inlet and

6

D

outlet of the orbit. Anteriorly, it is continuous

5

Inferior rectus. M. rectus inferior. o: Common

with the adjacent periosteum, posteriorly with

the dura. A

7

tendinous ring. i: Along an oblique line about

19

Orbital septum. Septum orbitale. Connective

6 mm behind the corneal margin. A: Depression

and lateral rotation of superior pole of eyeball. I:

tissue septum partly reinforced by tendon. It

8

Oculomotor nerve. B C D

passes from the orbital margin below the orbic-