Exam 4 Special Sense Organs

Question 1

What is the eye derived from

Answer 1

Ectoderm

Question 2

Neuroectoderm of the forebrain forms what?

Answer 2

Retina and pigmented structures

Question 3

Surface ectoderm of the eye forms what

Answer 3

Lens and cornea

Question 4

What forms from neural crest mesenchyme

Answer 4

Fibrous coats (sclera)

Question 5

What are the 3 coats/tunics of the eye

Answer 5

Fibrous (outermost), vascular, and nervous tunic(retina)

Question 6

If pressure inside the eye increases what happens to the sclera

Answer 6

It will not bulge, it maintains shape

Question 7

What structures pass through the tiny openings in the sclera

Answer 7

Neurons and blood vessels

Question 8

What attach directly to the sclera

Answer 8

Extraocular muscles

Question 9

What is significant about the anterior portion of the sclera

Answer 9

It transitions to the cornea at the limbus and is lined with conjuctiva

Question 10

What is the transition between the sclera and the cornea

Answer 10

At the limbus

Question 11

What is significant about the posterior portion of the sclera

Answer 11

It is continuous with the fibrous sheath that covers CN II, contains subarachnoid space filled with CSF

Question 12

What part of the fibrous tunic is the cornea

Answer 12

The anterior portion

Question 13

What is the important function of they cornea

Answer 13

It is the primary refractory part of the eyeball

Question 14

Which part of the cornea is convex

Answer 14

To the anterior

Question 15

What are the 5 layers of the cornea from anterior to posterior

Answer 15

Corneal epithelium, anterior limiting lamina, substantia propria, posterior limiting lamina, endothelium

Question 16

What is the corneal epithelium continuous with

Answer 16

The conjunctiva

Question 17

What is the largest part (layer) of the cornea

Answer 17

Substantia propria

Question 18

The endothelium of the cornea is the most internal layer and has what purpose

Answer 18

Covers inside surface of the cornea and lines the iridocorneal layer

Question 19

What 3 structures are a part of the vascular tunic

Answer 19

Choroid, ciliary body, and iris

Question 20

The blood vessels of the choroid are heavily supplied by what

Answer 20

Autonomic, vasomotor fibers that may have a cooling effect

Question 21

How is the choroid attached to the sclera

Answer 21

Loosely except where the optic nerve penetrates, here it is firmly attached to the sclera

Question 22

What is the pigment of the choroid

Answer 22

Darkly pigmented to limit passage of light from sclera to retina and vice versa

Question 23

Where is the ciliary body located in relation to the choroid and iris

Answer 23

Continuous with the choroid to the posterior and the iris to the anterior

Question 24

What is the purpose of the ciliary body

Answer 24

It suspends the lens and produces the aqueous fluid found in the anterior segment of the eye, some GAGS of the vitrous body

Question 25

What does the ciliary body contain

Answer 25

The ciliary muscle - contraction of the muscle allows the lens to become more convex allowing near vision

Question 26

What does the iris divide

Answer 26

The anterior segment into anterior and posterior chambers

Question 27

What is the iris composed of muscle-wise

Answer 27

Consists of two muscles that control the size of the pupil

Question 28

Sphincter pupillae contains what

Answer 28

Fibers arranged circumferentially that constrict the pupil

Question 29

What is the spincter pupillae innervated by

Answer 29

Parasympathetic fibers (CN 3)

Question 30

What does the dilator pupillae will cause what

Answer 30

Causes the pupil to become larger when it contracts

Question 31

What is the dilator pupillae innervated by

Answer 31

Sympathetic fibers - radially oriented

Question 32

What is the nervous tunic an outgrowth of

Answer 32

Outgrowth of diencephalon and can be considered to be a specialized portion of the brain

Question 33

What is the nervous tunic in contact with

Answer 33

The choroid externally and the vitreous body internally

Question 34

What are the ten layers of the retina

Answer 34

Pigmented layer (cementing layer), rods/cones, external limiting membrane, outer nuclear layer, outer plexiform layer, inner nuclear layer, inner plexiform layer, ganglion cell layer, nerve fiber layer, internal limiting membrane

Question 35

What do rods and cones synapse with

Answer 35

Inner nuclear layer cells

Question 36

Bipolar cells relay information to

Answer 36

The ganglion layer cells

Question 37

Multipolar cells carry info to where

Answer 37

The lateral geniculate body

Question 38

What do axons from the lateral geniculate body form

Answer 38

The optic radiation

Question 39

The axons forming optic radiation synapse where

Answer 39

Brodmann area 17 of the occipital lobe

Question 40

What structures are visible upon funduscopic exam

Answer 40

Optic disc and macula lutea

Question 41

Where is the optic disc

Answer 41

Point at which the optic nerve attaches to the eyeball

Question 42

Does the optic disc contain photoreceptors

Answer 42

Nope

Question 43

What enters the eye at the optic disc

Answer 43

Major blood vessels

Question 44

Where is the macula lutea

Answer 44

The darker area in the center of the fundus

Question 45

What is in the middle of the maculae lutea

Answer 45

The fovea centralis

Question 46

Where is the area of the clearest vision

Answer 46

The macula lutea

Question 47

What type of photoreceptor is found in the macula lutea

Answer 47

Cones

Question 48

What is aqueous humor

Answer 48

Clear fluid found on the posterior aspect of the ciliary body

Question 49

What secretes the aqueous humor

Answer 49

The ciliary processes

Question 50

Where is the aqueous humor secreted into

Answer 50

The posterior chamber; part of the anterior segment located posterior to the iris

Question 51

Where does the aqueous humor leave the eyeall

Answer 51

Through the scleral venous sinus

Question 52

What causes glaucoma

Answer 52

Increased pressure within the anterior segment of the eyeball - can result in blindness

Question 53

How does the lens allow for near vision

Answer 53

Increasing the convexity

Question 54

Is the lens vascular?

Answer 54

No

Question 55

What separates the anterior and posterior segments

Answer 55

The lens

Question 56

What is presbyopia

Answer 56

Lens gents harder with age resulting in more difficult near vision

Question 57

What are cataracts

Answer 57

Lens becomes less and less transparent

Question 58

What fills the posterior segment

Answer 58

Vitreous body

Question 59

What are characteristics of the vitreous body

Answer 59

Gelatinous and transparent

Question 60

What is the hyaloid canal

Answer 60

A vestigial structure connecting the optic nerve and posterior aspect of the lens.

Question 61

What did the hyaloid canal contain

Answer 61

Contained the fetal hyaloid artery and serves no functional purpose in the adult

Question 62

Where are lacrimal glands located

Answer 62

Superolaterally to the eyeball

Question 63

What do lacrimal glands do

Answer 63

Secrete tears that are carried to the surface of the eye by excretory ducts

Question 64

Where are lacrimal ducts found

Answer 64

In each eyelid below and medial to the eyeball

Question 65

What do lacrimal ducts do

Answer 65

Drain tears into the lacrimal sac

Question 66

Where is the lacrimal sac found

Answer 66

Found in a groove between the lacrimal bone and the maxilla, the most superior part of the nasolacrimal duct

Question 67

What does the nasolacrimal duct do

Answer 67

Drain tears from the lacrimal sac into the inferior nasal meatus

Question 68

What are tarsal glands

Answer 68

Modified sebacceous glands in each eyelid

Question 69

What do tarsal glands do

Answer 69

Secrete oily substance that covers tears upon binking reducing evaporation

Question 70

All arteries to the eyeball are branches of the _____

Answer 70

Ophthalmic artery

Question 71

What artery runs between the sclera and choroid

Answer 71

The long posterior ciliary artery (medial and lateral)

Question 72

How many short ciliary arteries enter the eyeball

Answer 72

6-12

Question 73

Where do the short ciliary arteries enter the eyeball

Answer 73

On the posterior surface forming a ring around the optic nerve

Question 74

How are the anterior ciliar arteries spread

Answer 74

3-4 over and 3-4 under the eyeball (total = 6-8)

Question 75

How does the central retinal artery travel

Answer 75

Via the optic nerve to retina where it spreads out into an extensive network

Question 76

What is special about the central retinal artery

Answer 76

It is the only artery that supplies the retina

Question 77

How do viens travel

Answer 77

With their respective arteries

Question 78

What is the nerve supply to the eyeball

Answer 78

Branches of the nasociliary nerve of the ophthalmic division of the trigeminal nerve

Question 79

What do long ciliary nerve supply

Answer 79

Sensory for the ciliary body, iris, and cornea

Question 80

What are the sensory nerves for the eyeball

Answer 80

Short ciliary nerves

Question 81

What do postganglionic sympathetic fibers extend from

Answer 81

The cavernous plexus passing through the ciliary ganglion

Question 82

What do postgang symp fibers go to

Answer 82

Reach the ciliaris and dilator pupillae muscles

Question 83

Where do postganglionic parasympathetic fibers extend from

Answer 83

The ciliary ganglion

Question 84

What do postgang parasymp supply

Answer 84

Ciliaris and sphincter pupillae muscles