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Flashcards in Histo - Eye Deck (26)
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1
Q

Explain the Anatomy of the Eye

A
2
Q

What is this?

A

Eye

3
Q

What is this?

A

Eye with Optic Nerve

4
Q

What are the 3 chambers of the eye?

A
  1. Anterior
    • btw corneal epithelium + anterior surface of iris
    • contains AQUEOUS HUMOR
      • pupillary part of lens
      • base of ciliary body
  2. Posterior
    • posterior surface of iris + lens
    • contains AQUEOUS HUMOR
      • lens
      • zonular fibers
      • ciliary processes
  3. Vitreous
    • Posterior to lens –> retina (lines it)
    • contains VITREOUS HUMOR
5
Q

What are the 3 tunics of the eye?

A
  1. Outer tunic
    • sclera (opaque)
    • cornea (transparent)
      • limbus = jxn (canal of schlem & trabecular meshwork)
  2. Middle tunic (Uvea)
    • vascular layer
    • ciliary body + choroid & iris
  3. Inner tunic
    • retina & pigment epithelium
6
Q

What are the 4 things in this image?

A
7
Q

What are the 5 layers of the cornea?

A
  1. Corneal epithelium
    • SSNK
  2. Bowman’s layer (membrane)
    • modified basement membrane (collagen 1 & 5)
  3. Corneal stroma
    • dense regular CT
    • keratocytes
    • ECM
      • Collagen 1, 5, 6
      • Proteoglycans
  4. Decemet’s membrane
    • ​Collagen 8
  5. Corneal endotheloum
    • not related to vascular endothelium
8
Q

What are the 4 key facts about the cornea?

A
  1. Transparent
    • 2/3 of light refraction!
  2. Avascular
    • NO BLOOD or lymphatic
  3. Immune privileged
    • can be transplanted w/ little risk
      • keratoplasty
    • little MHC expression
  4. Kept moist w/ tears
    • dry eye
9
Q

What are components of the Anterior Surface of the Cornea?

A
  1. Corneal epithelium
  2. Bowman’s membrane
  3. Stroma

Curvature affects vision

  • can reshape the STROMA w/ a laser!
10
Q

What are the components of the Posterior Surface of the Cornea?

A
  1. Decemet’s membrane
    1. Type 8 collagen
    2. hexagonal meshwork
  2. Corneal endothelium
    1. responsible for corneal DEHYDRATION
      1. ​Na+/K - ATPase

***MUTATIONS in Collagen 8 = FUCH’s Dystrophy***

  • corneal stromal dystrophy
    • ​thickened Decemet’s
    • Guttae (outpocketing)
      • ​both cause corneal edema
11
Q

What produces aqueous humor?

A

Aqueous humor = secreted by ciliary processes

  • Secreted into posterior chamber
  • moves thru pupil –> anterior chamber
  • Excess aqueous humor –>
    • resorbed by the SCLERAL VENOUS SINUS
    • aka CANAL of SCHLEM
12
Q

What is this?

A

Corneal-Scleral Junction

(and Canal of Schlem w/ Trabecular Meshwork)

  • Glaucoma = rise in intraocular pressure
    • caused by blockage of aqueous humor!
    • (normal intraocular pressure = ~23mmHg)
13
Q

What are the 2 Regions of the Ciliary Body?

A
  1. Uveal portion
    • continuous of choroid
    • ciliary muscle attached to lens by ZONULES of ZINN
    • fenestrated capillaries supplying blood to ciliary muscles
  2. Neuroepithelial portion
    • outer pigmented epithelial layer
    • inner non-pigmented epithelial layer
      • continuous w/ RETINA
      • secretes AQUEOUS HUMOR
14
Q

What is this?

A
15
Q

What is this?

A
16
Q

What is this?

A

Ciliary Body

  • SM
  • Pigment!
17
Q

What is this? What are the 4 important parts?

A

Lens (Middle of Eye) - Epithelium!

  1. Accomodation
    • ciliary muscles
  2. Lens capsule
    • basement membrane
  3. Lens epithelium
    • simple cuboidal epithelium or anterior
  4. Lens fibers
    • elongated lens epithelium remnants
    • lose nuclei & organelles
    • fill w/ CRYSTALLINGS & FILENSIN
      • transparency & conformation of lens
18
Q

What is this?

A

Lens Fibers

  • Fibers cells
    • ​filled w/ FILENSIN & CRYSTALLINS
19
Q

What is this?

A

Lens & Iris

  1. Iris = forms pupil
    • contains 2 muscles:
      1. Sphincter pupillae
      2. Dilator pupillae
  • Abundant melanocytes!
20
Q

What is Accomodation?

A

Accomodation

  • Cilliary muscles allow focus:
    • FLAT = see FAR
      • relaxed
    • ROUND = see CLOSE
      • tense
21
Q

What is shown in this image?

A
  1. Optic disc
    • where ganglion layer axons LEAVE the eye as optic nerve
  2. Fovea
    • Thinning due to fewer bodies & axons
    • NO RODS
    • INCREASED cones
    • Greatest visual acuity
  3. Macula Lutea
    • Axon of CONE cells
    • Yellowish region AROUND fovea
22
Q

10 Layers of the Retina

A

[CHOROID]

  1. Pigment epithelium

    2. Layer of rods and cones

(Processing of light starts here)

3. Outer limiting layer

4. Outer nuclear layer

(nuclei of RODS & CONES)

5. Outer plexiform layer

6. Inner nuclear layer

7. Inner plexiform layer

8. Ganglion cell layer

(Closest to LIGHT)

9. Nerve fiber layer

(Leave retina via OPTIC NERVE)

10. Inner limiting layer

[VITREOUS

23
Q

What are the 10 layers?

A
24
Q

What is this?

A

Pigment Epithelium of Retina vs. Choroid

  • Pigment epithelium = THIN
  • Choroid = THICK & BLACK
25
Q

What is this?

A

Lacrimal Gland

  • Produce tear film
    • continuous secretion
    • small, lightly stained granules
    • O2, metabolities, proteins,
    • lysozymes!
26
Q

What is this?

A

Eyelid

  • Covered by CONJUCTIVA & SKIN
  • Hair follicles
    • eyelashes
  • Skeletal muscle
    • ORBICULARIS OCULI
    • innv = facial n.
  • Tarsal Glands
    • secrete sebum
    • adds to tear film