Crystalline Lens Development

mxrieen avatar
mxrieen
·
·
Download

Start Quiz

Study Flashcards

36 Questions

What is the embryonic nucleus composed of?

Primary lens cells

What happens to the nuclei of young outer lens fibers as they age?

They disintegrate and lose their nuclei and organelles

What contributes to the remaining nuclei after the formation of the embryonic nucleus?

Anterior lens epithelium

What denotes the boundaries of the fetal nucleus during slit lamp examination?

Y inverted sutures

Where is the lens located in the eye?

Posterior to the vitreous chamber

Which part of the lens forms new fiber cells?

Lens epithelium

What causes a change in the shape of the lens, increasing its dioptric power for accommodation?

Contraction of the ciliary muscle

What is the name of the area of nonadhesion between the vitreous and lens?

Retrolental space of Berger

What are the dimensions of the anterior radius of curvature?

8-14 μm

Which part of the lens is attached to the anterior vitreous face by Wieger’s ligament?

Posterior lens surface

What part of the lens forms the basis of the nucleus and cortex?

Lens fibers

Where is the germinative zone located in relation to the equator?

Just anterior to it

What is the refractive power of the unaccommodated lens?

20 D

Where is the nucleus of the lens located?

In the embryonic nucleus

What are the dimensions of a lens fiber in cross section?

3 by 9 μm

Which region of the lens contains the thickest fibers?

Equator

What contributes to the gradient refractive index in lens fibers?

Water-soluble proteins

What is the shape of the lens fibers when viewed in cross section?

Hexagonal

What is responsible for changing the lens shape during accommodation?

Relaxation of ciliary muscle

Which structure attaches the lens to the ciliary body?

"Zonules of Zinn"

What is the refractive index of the lens nucleus?

$1.50$

Which region of the lens contains the thinnest fibers?

Posterior pole

What is responsible for maintaining the structure of lens fibers?

Microtubules and filaments

What happens to lens fibers as growth continues?

They become larger and compacted as insoluble protein in the nucleus

What is the primary function of the lens?

Refraction of light

Which source provides nutrients to the lens?

Aqueous humor

What is the primary protector against oxidative damage in the lens?

Glutathione

What is the main cause of loss of accommodative ability in aging?

Changes in ciliary body

What is the greatest cause of blindness related to the lens?

Cataract

Which type of cataract is known for its yellow coloration?

Nuclear cataract

What is the main risk factor for developing a posterior subcapsular cataract?

Long-term use of high-dose steroids

What mechanism is presumed causative for cataract development?

Fluid and ion imbalance

Where does the metabolic activity mostly occur in the lens?

Anterior epithelium

Which type of light absorption can produce oxidative changes causing the formation of free radicals?

Ultraviolet (UV) light absorption

What is the primary function of the lens metabolism?

Regulation of water movement to create the correct constituents optically

What causes cellular damage in the lens due to excess sorbitol?

Osmotic gradient favoring water movement into the lens

Learn about the development of the crystalline lens in the 27th day of development, including the formation of the lens placode, lens pit, and lens vesicle. Understand the composition of the lens vesicle and its significance in optic development.

Make Your Own Quizzes and Flashcards

Convert your notes into interactive study material.

Get started for free

More Quizzes Like This

Crystalline vs
11 questions

Crystalline vs

InvaluableRhodochrosite avatar
InvaluableRhodochrosite
Anatomy 2 Exam 1
36 questions

Anatomy 2 Exam 1

SteadfastReasoning avatar
SteadfastReasoning
Use Quizgecko on...
Browser
Browser