Week 1: Gross Anatomy

Question 1

Function of;

• Cornea
• Iris
• Pupil
• Lens
• Ciliary Muscles
• Fovea
• Retina

Answer 1

• Cornea: Protects eye from light
• Iris: Coloured muscle regulates pupil size
• Pupil: Regulates light input
• Lens: Focuses images on retina
• Ciliary Muscles: Controls shape of lens accommodation
• Fovea: point of central focus contains most cones
• Retina: Contains photoreceptors

Question 2

Sagittal

Answer 2

Divides body into left and right

Question 3

Transverse/Horizontal

Answer 3

Divides body into superior and inferior (top and bottom)

Question 4

Coronal / Frontal

Answer 4

Divides body into front and back

Question 5

Anterior

Answer 5

At or near the front (of the body)

Question 6

Posterior

Answer 6

At or near the back of the body

Question 7

Lateral

Answer 7

Further from the middle of the body

Question 8

Medial

Answer 8

Nearer the middle of the body

Question 9

Superior

Answer 9

Towards the head or top of the body (above)

Question 10

Inferior

Answer 10

Further from the head/top (so below)

Question 11

1. Orbit to the cranial cavity=
2. Orbit to the maxillary sinus=
3. Orbit to the nasal cavity and paranasal sinus=
4. Orbit to the infra-temporal fossa (near cheekbone)=

Answer 11

1. Inferior
2. Superior
3. Lateral
4. Medial

Question 12

Eyeball length: sagittal vertical diameter

Eyeball Axil Length from cornea to retinal surface

Answer 12

Approx 23.7mm vertical

Approx 24mm, 25mm including tissues

Question 13

Growth of eyeball from birth to 3

Answer 13

16mm at birth to 22.5mm by 3 y/o

Eyeball full size at 13

Question 14

Eyeball position within the orbit in newborns

Answer 14

The angle and distance between the two eyes changes during growth as skull/orbit expand especially in infancy and childhood.

• at 2 month embryo: 180 degrees
• 3 month embryo: 105 degrees
• birth: 71 degrees
• adult: 68 degrees

Question 15

Fibrous tunic

Answer 15

Cornea and sclera

Question 16

Vascular tunic

Answer 16

Iris, ciliary body, choroid

Question 17

Cornea function

Answer 17

Refracts light as enters the eye

Question 18

Sclera function

Answer 18

White of the eye, provides shape and protects inner segments of eye

Question 19

Iris

Answer 19

Coloured proteins, regulates amount of light entering eye

Question 20

Ciliary body function

Answer 20

Secretes aqueous humour and alters shape of lens for accommodation (looking near and far)

Question 21

Retina function

Answer 21

Receives light and converts it into receptor potentials and nerve impulses which output to the brain via the optic nerve

Question 22

Lens function

Answer 22

Refracts light

Question 23

Function of aqueous humour

Answer 23

Helps maintain shape of eyeball, jelly-like and supplies oxygen and nutrients to lens and cornea

Question 24

Vitreous humour function

Answer 24

Liquid helps maintain the shape of eyeball and keeps retina attached to choroid