Histology of the Special Sensory Organs

Question 1

Layer of the eye, composed of:

• cornea
• sclera

Answer 1

Fibrous tunic (outer coat or external layer)

Question 2

Layer of the eye, composed of:

• iris
• ciliary body (and the aqueous humor)
• choroid plexus

Answer 2

Vascular/muscular tunic (uvea or middle layer)

Question 3

Layer of the eye that contains the retina

Answer 3

Nervous tunic (inner layer)

Question 4

Corneal external epithelium

Answer 4

Stratified squamous non-keratinized epithelium

Question 5

Corneal endothelium

Answer 5

Simple squamous

Question 6

Scleral tissue

Answer 6

Dense irregular connective tissue

Question 7

Lens epithelium

Answer 7

Simple cuboidal

Question 8

Retinal cell for night-vision or scotopic vision

Answer 8

Rods

Question 9

Retinal cell for day-vision or photopic vision and color-vision

Answer 9

Cones

Question 10

The structure that secretes the aqueous humor

Answer 10

Ciliary processes (or the ciliary body)

Question 11

The neural retina detaches from this structure in retinal detachment

Answer 11

Pigment epithelium

Question 12

5 layers of the cornea

Answer 12

1. Corneal epithelium (stratified squamous non-keratinized)
2. Bowman membrane
3. Corneal stroma
   * * Dua’s layer (potentially new layer)
4. Descemet membrane
5. Corneal endothelium (simple squamous)

(mnemonic: EBCDE)

Question 13

Choroid plexus tissue

Answer 13

Loose connective tissue

Question 14

10 layers of the retina

Answer 14

1. Retinal pigment epithelium
2. Photoreceptors
3. Outer limiting membrane
4. Outer nuclear membrane
5. Outer plexiform membrane
6. Inner nuclear membrane
7. Inner plexiform membrane
8. Ganglion cell layer
9. Optic nerve fibers
10. Inner limiting membrane

Question 15

Cells in the organ of Corti that act as the receptor for hearing

Answer 15

Hair cells

Question 16

This organ, primarily for hearing, lies on the basilar membrane of the ear

Answer 16

Organ of Corti

Question 17

The UPPER bony passage of the cochlea, filled with PERILYMPH

Answer 17

Scala vestibuli

Question 18

The MIDDLE passage of the cochlea, filled with ENDOLYMPH

Answer 18

Scala media (or cochlear duct)

Question 19

The LOWER bony passage of the cochlear, filled with PERILYMPH

Answer 19

Scala tympani

Question 20

Fluid substance in the cochlea:

• similar to intracellular fluid (high K, low Na)
• secreted by the STRIA VASCULARIS
• found in the membranous labyrinth: utricle, saccule, SCCs, cochlear duct

Answer 20

Endolymph (or Scarpa fluid)

Question 21

Fluid substance in the cochlea:

• extracellular fluid
• comparable to plasma and CSF
• continuous with the CSF of the subarachnoid space via the perilymphatic duct

Answer 21

Perilymph (or Cotunnius liquid, or liquor Cotunnii)