anatomy tutorial

Question 1

what is wrong here?

Answer 1

• pupil on right slightly smaller
• right lid droop

Horners syndrome

Question 2

what muscle causes eye opening?

Answer 2

-elevator with Muller’s muscle (controlled by CNIII oculomotor under sympathetic control)

Question 3

what muscle closes the eye?

Answer 3

-Orbicularis oculi controlled by (CNVII facial nerve)

Question 4

what is compromised in corners syndrome?

Answer 4

Muller muscle (innervated by CNII oculomotor)

Question 5

how does the lease change shape/focal distance?

Answer 5

• depending on how the zones contract/relax
• lens wants to spring into a sphere but zones pull it flat
• ciliary muscle is a sphincter, so when it contracts its lumen gets smaller and when it relaxes the lumen gets bigger
• flat surfaces do not refract/bend light rays, so a curved surface causes refraction/bend light rays
• if you want to focus on something far away you need light to bend a different way compared to focusing close up
• if you want to focus on something far away you need the lens to be more flat
• light needs to bend more to see a near object
• if you want to see something far away you need to make the lens flat by widening the ciliary process by relaxing it, causing tension on the zonules causing the lens to go flat

Question 6

how do you see things far away using ciliary muscle and zonules?

Answer 6

-if you want to see something far away you need to make the lens flat by widening the ciliary process by relaxing it, causing tension on the zonules causing the lens to go flat

Question 7

what is affected to cause blindness in right eye?

Answer 7

a

Question 8

what must be effected to cause bitemporal hemiopia ?

Answer 8

b- optic chiasma

Question 9

what cause nasal hemiapia in right eye?

Answer 9

problem with c

Question 10

what causes the left sided hemianopia?

Answer 10

• affecting both eyes so problem must be after the crossing point
• will look at the right side of brain if ordering brain scan as it is affecting left view
• could be affecting anywhere between d and f

Question 11

what is the second last view affecting?

Answer 11

superior retina can go straight to

• must be problem in right half of brain
• lower field affected which goes to superior retina, stays in superior nerve, superior part of chiasma and into the lobe
• must be a problem in right superior lobe

Question 12

how would a RAPD in right eye present?

Answer 12

• good direct and consensual pupil contraction when light shone in left eye
• not as good direct or consensual contraction when light shone in right eye (depends how much tumour is pressing on afferent optic nerve)
• must do RAPD swinging light test by shining light in left eye and then right eye before pupil dilates again, if right eye affected then there will be a dilation in both eyes as you move the light from left to right as the brain thinks the light has been dimmed