OcAnat_Test3

Question 1

Ectoderm, mesoderm, and endoderm come from?

Answer 1

Epiblast

Question 2

What germ tissues do the eye parts develop from?

Answer 2

Ectoderm and Mesoderm

Question 3

What happens in Week 4(day 22-28)

Answer 3

Optic sulcus
Optic vesicle, mesenchymal sheath begins
Mesenchymal sheath completes
Retinal disk, RPE, lens placode
Optic stalk, hyaloid vessels, primordia of EOM

Question 4

What is induction

Answer 4

the influence that one developing structure has on another

Question 5

What forms the retinal pigment epithelium?

Answer 5

Cells of the superotemporal wall of the optic vesicle.

Question 6

The walls of the optic vesicle are continuous with what structure?

Answer 6

Neuroectoderm of the future brain

Question 7

What is mesenchyme derived from?

Answer 7

Mesoderm (middle germ layer)
Neural crest (originate from neuroectoderm)
This is a descriptive term and does not imply an origin from any particular embryonic germ layer.

Question 8

What is the retinal disk?

Answer 8

Distal face of the optic vesicle.
Disk-shaped thickening of the neural ectoderm.
Will become the neural retina.

Question 9

What does lens placode formation coincide with?

Answer 9

Constriction of the optic vesicle which forms the optic stalk

Question 10

What two things are related to each other at the end of week 4?

Answer 10

Vascularization and pigmentation

Question 11

What days does week 5 consist of?

Answer 11

Days 29-35

Question 12

What structures appear in week 5?

Answer 12

Invagination of retinal disk and lens placode
Optic cup forms, blood vessels enter the choroidal fissure
Lens vesicle pinched, corneal epithelium, primary vitreous, hyaloid vasculary

Question 13

The optic vesicle turns into what structure?

Answer 13

The optic cup.

day 29-32; 5th week.

Question 14

How do the blood vessels gain access to the optic cup?

Answer 14

Through the choroidal fissure.

Question 15

How does the lens vesicle come about?

Answer 15

Through the pinching off of the lens placode from the surface ectoderm

Question 16

During week 5, what structures does the hyaloid artery supply?

Answer 16

Lens vesicle

Developing retina

Question 17

Is the choroidal fissure ventral or dorsal to the optic stalk?

Answer 17

It is on the ventral surface.

Question 18

What is the purpose of the vasa hyaloidea propria

Answer 18

Supplying the vitreous chamber. Tiny branches of the hyaloid artery.

Question 19

What blood network supplys the lens?

Answer 19

tunica vasculosa lentis.

Originates from the hyaloid artery.

Question 20

What is so special about the lens when it is super grown?

Answer 20

It doesn’t need a blood supply.
Hyaloid artery degenerates
Hyaloid canal remains.

Question 21

What does the proximal portion of the central retinal artery become?

Answer 21

Central retinal artery, which supplies the retina.

Question 22

When does melanin appear in RPE?

Answer 22

Day 33.

Question 23

What days are in week 6?

Answer 23

Days 36-42

Question 24

What is the dominating factor in week 6?

Answer 24

The closure of the embryonic choroidal fissure.

Question 25

Thick inner wall of optic cup becomes... | Thin outer wall of optic cup becomes...

Answer 25

1. Neural retina | 2. RPE

Question 26

Where do the primary lens fibers come from?

Answer 26

Cells of the posterior wall of the lens vesicle. The elongation of these cells fills the cavity of the lens vesicle by the end of the 7th week.

Question 27

Who forms the corneal epithelium?

Answer 27

The surface ectoderm after it separated from the lens vesicle.

Question 28

Cells of basal layer of corneal epithelium are connected via....

Answer 28

Maculae adherens

Question 29

Cells of the superficial layer of the corneal epithelium are connected via

Answer 29

Zonulae adherens | Zonulae occludens.

Question 30

WHen do the secondary vitreous appear?

Answer 30

At the end of week 6. It pushes the primary vitreous inward towrd the lens and detach it from the sensory retina, except at periphery and optic disk area.

Question 31

A lot of things happen in week six. GIve me a list

Answer 31

``` RPE Neural retina: outer nuclear zone, marginal zone Choroidal fissure closes Secondary vitreous appears Primary lens fibers appear Cornea epithelium appear ```

Question 32

What are the honorable mention structures of week 6?

Answer 32

Eyelid Nasolacrimal duct Periocular vasculature Orbital bones: Maxilla.

Question 33

What does the first wave of mesenchyme cells form?

Answer 33

Corneal endothelium | Trabecular meshwork endothelium

Question 34

What does the second wave of mesenchyme cells form?

Answer 34

Pupillary membrane, which is the primordium of the anterior border layer and stroma of the iris.

Question 35

What is the purpose of the pupillary membrane?

Answer 35

Separates the anterior chamber from the posterior chamber

Question 36

What does the third wave of mesenchyme cells form?

Answer 36

Primary corneal stroma - fibroblast | Secondary corneal stroma - keratocytes and collagen

Question 37

The primary lens fibers become....

Answer 37

Embryonic nucleus

Question 38

What two neuroblastic layers does the transient layer of CHievtiz separate?

Answer 38

Inner neuroblastic layer | Outer Neuroblastic layer

Question 39

What happens to the mesencymal capsule during week 7?

Answer 39

Choroid and Sclera gets formed

Question 40

CHoroid is homologous in origin with?

Answer 40

Pia mater | Arachnoid mater

Question 41

Sclera is homologous in origin with?

Answer 41

Dura mater around the optic nerve and brain.

Question 42

What happens to the optic stalk in the 8th week?

Answer 42

It becomes the optic nerve

Question 43

Inner neuroblastic layer is differentiated into

Answer 43

Ganglion cells Amacrine Cells Mueller Cells Another name for INBL is marginal layer of HIS

Question 44

The outer neuroblastic layer is differentiated into

Answer 44

Bipolar cells Horizontal cells Rods and COnes

Question 45

What is the canal of cloquet

Answer 45

When secondary vitreous push its way anteriorly and laterally, crushing the primary vitreous and vasa hyaloidea propria centrally. Clearly formed by 5th month.

Question 46

What structures evolve from the ectoderm?

Answer 46

Surface ectoderm Neuroectoderm Neural crest

Question 47

What structures are made out of the surface ectoderm?

Answer 47

``` Corneal epithelium Conjunctiva epithelium Lacrimal glands Crystalline lens Eyelid structures Epithelium lining the nasolacrimal system ```

Question 48

When does the monolayer cells of cornea turn multilayered?

Answer 48

6 weeks. After that neural crest cells(mesenchyme) form the corneal endothelium at week 7.

Question 49

What happens at 7th week in the cornea?

Answer 49

COrneal epithelium is separated from the corneal endothelium by a diffuse basal lamina.

Question 50

When does the descemet's layer form?

Answer 50

When the endothelial cells are confluent

Question 51

What happens after the endothelium is formed in the cornea?

Answer 51

Neural crest cells rub in b/w the endothelium and epithelium and turn primary stroma into secondary stroma

Question 52

Where does the choroidal capillaries first appear?

Answer 52

At the posterior pole and then differentiate peripherally.

Question 53

What is the order of appearance of choroidal circulation

Answer 53

Choriocapillaris forms first. Next is short posterior ciliary arteries are added to supply choriocapillaris. Long posterior ciliary arteries bypass the developing choroid.

Question 54

Primary lens fibers appear in week 6 and week 7

Answer 54

6: transformation of the posterior cells of the lens vesicle into primary lens fibers 7: Filling of the cavity of primary lens fibers.