Lab 9- The Eye

Question 1

What is the diameter of the human eye?

Answer 1

About an inch

Question 2

What are the main components of the lacrimal apparatus?

Answer 2

• Lacrimal Glands
• Lacrimal Canals
• Lacrimal Sac
• Nasolacrimal Duct

Question 3

What is the purpose of the lacrimal apparatus?

Answer 3

To produce and secrete tears that flow laterally to medially on the eyeball

Question 4

What enzyme is contained in tears?

Answer 4

Lysozyme

Question 5

What are the medial and lateral canthus?

Answer 5

Junctions of the upper and lower eyelids

Question 6

What is the function of the conjunctiva?

Answer 6

Mucous membrane lining the eyelid. To secrete mucus to help lubricate the eye

Question 7

Where are ciliary glands located and what is their function?

Answer 7

Between hair follicles; they secrete fluid to lubricate the eye

Question 8

What do Meibomian glands secrete?

Answer 8

(Tarsal) Close to eyelashes and secrete An oily substance

Question 9

Name the extrinsic eye muscles.

Answer 9

• Lateral Rectus
• Inferior Rectus
• Medial Rectus
• Inferior Oblique
• Superior Rectus
• Superior Oblique

Question 10

What are the three tunics of the eye?

Answer 10

• Outer Fibrous tunic
• Middle Vascular tunic (Uvea)
• Innermost Tunic (Neural Tunic)

Question 11

What does the outer fibrous tunic consist of?

Answer 11

Also called the Uvea
* Sclera - white of eye (helps maintain shape, aids
* Cornea

Question 12

What makes up the middle vascular tunic?

Answer 12

• Choroid Coat (posterior)
• Ciliary Body (anterior)
• Iris (muscular ring around pupil)

Question 13

What is the function of the ciliary muscles and processes

Answer 13

Muscles by way of suspensory ligaments To control lens shape
And processes secrete aqueous humor

Question 14

What does the iris do?

Answer 14

Regulates the diameter of the pupil

Question 15

What are the two layers of the neural tunic?

Answer 15

• Outer pigmented layer
• Inner neural layer - contains rods and cones

Question 16

What are rods and cones?

Answer 16

Photoreceptors in the retina

Question 17

Fill in the blank: The lacrimal apparatus flushes tears into the _______.

Answer 17

Lacrimal Sac

Question 18

True or False: The conjunctiva is a muscular structure.

Answer 18

False

Question 19

What is the function of cones in vision?

Answer 19

Cones are for more acute vision and see in color

Cones require high light and are not used in the dark.

Question 20

What is the function of rods in vision?

Answer 20

Rods are adapted for low light and see in gray tones

Rods are not as acute as cones.

Question 21

What is the blind spot?

Answer 21

The blind spot (optic disk) is where there are no rods or cones

This area is crucial in understanding visual perception.

Question 22

What is the macula lutea?

Answer 22

The macula lutea is the area of greatest visual acuity with high cone concentration

It is essential for sharp central vision.

Question 23

What is the fovea centralis?

Answer 23

The fovea centralis is the center of the macula lutea and contains only cones

It is responsible for the highest visual acuity.

Question 24

What role does the lens play in vision?

Answer 24

The lens focuses light on the retina

It is held in place by suspensory ligaments.

Question 25

How does the shape of the lens change?

Answer 25

Contraction of the ciliary body muscle changes the shape of the lens ## Footnote This process is crucial for focusing on objects at varying distances.

Question 26

What are cataracts?

Answer 26

Cataracts are a result of the hardening of the lens ## Footnote This condition can impair vision significantly.

Question 27

What is the difference between aqueous humor and vitreous humor?

Answer 27

Aqueous humor is constantly made and reabsorbed; vitreous humor is not Aqueous humor is located in front of the lens, while vitreous humor is behind it.

Question 28

What are the three cell layers of the retina?

Answer 28

1. Photoreceptor cells 2. Bipolar cells 3. Ganglion cells ## Footnote These layers are arranged with photoreceptor cells deepest inward.

Question 29

Where do rods and cones synapse?

Answer 29

Rods and cones synapse onto bipolar cells, which then synapse onto ganglion cells ## Footnote This synaptic arrangement is essential for visual signal processing.

Question 30

What is the function of the optic nerve?

Answer 30

The axons of the ganglion cells join to leave the eyeball as the optic nerve ## Footnote This is critical for transmitting visual information to the brain.

Question 31

What holds the lens in place?

Answer 31

Suspensory ligaments

Question 32

Where do and cones converge?

Answer 32

Rods converge on bipolar cells while cones have a one to one ratio

Question 33

What is presbiopia

Answer 33

“Old vision”, the elasticity of the lens decreased with age, resulting in difficulty in focusing for close vision

Question 34

What is a blockage or infection in the tarsal gland

Answer 34

A chalazion

Question 35

What is an inflammation of the ciliary glands

Answer 35

A sty

Question 36

Antior of vascular tunic

Answer 36

Becomes the intrinsic muscles of the eye which change the diameter of the pupil and the shape of the lens

Question 37

Sclera

Answer 37

The white of the eye Helps maintain shape, aids in movements, and protects internal structures

Question 38

Cornea

Answer 38

Transparent avascular structure that allows light to enter the eye and aids in focusing

Question 39

Innermost tunic

Answer 39

The neural tunic, aka the retina

Question 40

Choroid coat

Answer 40

Dark layer with a large amount of dark melanin containing cells. In other animals had a tapetum lucidum

Question 41

How do suspensory ligaments work

Answer 41

Flatten lens for long distance and round up for near vision