Lecture 34. Special sense

Question 1

What is embedded in the extra occular fat

Answer 1

nerves and blood vessels

Question 2

what are the attachments of the levator palpebrae superioris muscle

Answer 2

conjunctivia and the tarsal plate, connective tissue in the eyelid

Question 3

What innervates the levator palpebrae superioris

Answer 3

CN3, parts of the fibers are also innervated by the sympathetic fibers.

Question 4

What happens if patient cannot fully open eye

Answer 4

ptosis, signs of injury to sympathethic nervous system

Question 5

What supplies sympathetic fibers to head and neck

Answer 5

T1

Question 6

What is the conjunctiva

Answer 6

single layer epithelium that covers the cornea

Question 7

What is the conjunctiva sac

Answer 7

the reflection of the conjunctivia that collects tears

Question 8

What are the 3 layers of the eyeball

Answer 8

1. fibrous
2. vaculature
3. nervous

Question 9

What composes the fibrous layer of the eye

Answer 9

posterior 5/6 : sclera

anterior 1/6: cornea

Question 10

What is the function of the sclera

Answer 10

protect the eyeball
shapes the eyeball
attachment site for the extraocular muscle
allows penetration of the optic nerve and opthalmic artery

Question 11

What penetrates the sclera

Answer 11

optic nerve and opthalmic artery

Question 12

What is the function of the cornea

Answer 12

focus light on the retina

Question 13

What composes the vascular layer of the eye

Answer 13

posterior 5/6: chorioid : supplies blood to retina
anterior 1/6 turns into
-ciliary body : mass of smooth muscle fibers
- iris: controls the size the pupil ( smooth muscle fibers)- disc that sits in front of lens

Question 14

How are the cilliary body connected to the lens

Answer 14

through suspensory ligaments (tendons of ciliary body)

Question 15

What is the function f the ciliary body

Answer 15

hold lens in place and change convexity of lens

Question 16

What composes the nervous layer of the eye

Answer 16

posterior 3/4 : retina, contains numerous receptors
anterior 1/4: epithelial layer loaded with melanin
-separated by the line ora serata

Question 17

where does the anterior 1/4 of the nervous layer of the eye extend to

Answer 17

the back of the iris

Question 18

What is the optic disc

Answer 18

exact exit point of the optic nerve and opthalmic artery , the artery is surrounded by the optic nerve.
has no photoreceptors

Question 19

What is the macula lutea

Answer 19

has a high number of photoreceptors, and the fovea is the very center of the macula lutea

Question 20

What is the fovea

Answer 20

highest concentration of cones

Question 21

What is the function of the ciliary body

Answer 21

arranged in concentric layers ( like a sphincter) , when it contracts the diameter of the opening of the ciliary body - it becomes narrower , suspensory ligaments will be lose and the convexity increases, when the ciliary body relazes the convexity decreases

Question 22

what happens when you have parasympathetic and sympathetic innervation of the ciliary body

Answer 22

sympathetic: see far, relax the ciliary body, causes flattening of lens
parasymp: see near, contract ciliary body

Question 23

what are the 2 sets of muscles in the iris

Answer 23

circular and radial

Question 24

what causes pupil to decrease / increase

Answer 24

decrease: ( parasympathetic), caused by circular muscle contraction
increase: ( sympathetic), caused by radial muscle contraction

Question 25

What are the 3 chambers

Answer 25

1. anterior chamber: cornea to iris
2. posterior chamber: iris to lens
3. vitreous chamber: lens to retina

Question 26

What fluid fills the anterior and posterior chamber

Answer 26

ciliary body produces the aqueous humor

Question 27

How does aqueous humor flow

Answer 27

made by ciliary body from the posterior chamber to the anterior chamber to the veins in the cornea and sclera junction

Question 28

what does the aqueous humor do

Answer 28

nourishes the structure and removes waste material

Question 29

what is the difference between glaucoma and cataracts

Answer 29

glaucoma: high pressure at cornea : build up of pressure
cornea: hardening of lens

Question 30

What is the lacrimal apparatus

Answer 30

consists of lacrimal gland and ducts

Question 31

Function of lacrimal gland

Answer 31

produces tears directed towards medial corner of the eye which contain ducts ( lacrimal canaliculi), drain tears into the larcrimal sac contained within lacrimal fossa of the larcrimal bone

Question 32

What is the nasolacrimal duct

Answer 32

It is the distal contunuation of the lacrimal sac that empties into the inferior nasal meatus- through parasympathetic fibers