Visual system

Question 1

What is the part of the retina that is most sensitive to light?

Answer 1

Pigment epithelium

Question 2

What does the inner segment of the rod contain?

Answer 2

cell nucleus and mitochondria

Question 3

The outer segment of the rod contains discs that contain light sensitive _________.

Answer 3

rhodopsin

Question 4

What does the inner segment of a cone contain?

Answer 4

cell nucleus and mitochondria

Question 5

The outer segment of the cone contents the discs that contain light sensitive _______.

Answer 5

iodopsin

Question 6

Refraction occurs tat the _________ and at the _______.

Answer 6

cornea; lens

Question 7

Refractive power of the _______ is greater, but the ______ can change its shape.

Answer 7

cornea; lens

Question 8

At the _____, interring cell layers are pushed aside.

Answer 8

fovea

Question 9

Rods and cones are found at the fovea (T/F).

Answer 9

FALSE; just cones

Question 10

At the _____ ____ there is a blind spot due to emerging retinal arteries.

Answer 10

optic disc

Question 11

More ________ in the central retina = better visual acuity.

Answer 11

cones

Question 12

More ______ in the peripheral retina = better for movement.

Answer 12

rods

Question 13

How many rods are located in the retina?

Answer 13

120 milion

Question 14

How many cones are located in the retina?

Answer 14

6 million

Question 15

Cones are sensitive to what 3 colours of the visible spectrum?

Answer 15

red, green and blue

Question 16

Trace the visual pathway, starting from the retina.

Answer 16

Retina; optic nerve; optic chiasm; optic tract; lateral geniculate nucleus of the thalamus; optic radiation; occipital lobe

Question 17

Left visual field projects to the _______ cortex, and vice versa.

Answer 17

right

Question 18

The ________ stream= where, how, and spatial vision

Answer 18

dorsal

Question 19

The ______ stream - what, object vision

Answer 19

ventral

Question 20

What muscle causes elevation of the eye?

Answer 20

superior rectus

Question 21

What muscle causes depression of the eye?

Answer 21

inferior rectus

Question 22

What muscles cause adduction and abduction of the eye, respectively?

Answer 22

medial rectus; lateral rectus

Question 23

What muscle is innervated by CN IV?

Answer 23

superior oblique

Question 24

What nerve innervates inferior oblique?

Answer 24

CN III

Question 25

What nerve causes lateral eye movements?

Answer 25

CN VI

Question 26

The _______ _______ muscle is aligned with the axis of the eyeball in the adducted eye.

Answer 26

superior oblique

Question 27

Contraction of the superior oblique will lead to _______ of the adducted eyeball.

Answer 27

depression

Question 28

The ______ ______ muscle is perpendicular to the axis of the eyeball in the abducted eye.

Answer 28

superior oblique

Question 29

Contraction of the superior oblique muscle in an abducted eye will lead to _______ of the eyeball.

Answer 29

intorsion

Question 30

Oculomotor nerve (CN __) innervates all extraocular muscles except what two?

Answer 30

1. Superior oblique | 2. Lateral rectus

Question 31

What nerve is the superior oblique muscle innervated by?

Answer 31

trochlear nerve (CNIV)

Question 32

What nerve is the lateral rectus innervated by?

Answer 32

Abducens (CN VI)

Question 33

Where is the oculomotor nucleus found in the brainstem?

Answer 33

midbrain

Question 34

Where is the trochlear nucleus found?

Answer 34

rostral pons

Question 35

Where is the abducens nucleus found?

Answer 35

Caudal pons

Question 36

Motor cranial nerves receive input from the primary motor cortex via the ____________ tract.

Answer 36

corticobulbar

Question 37

What is the specialized area of the cortex that controls eye movements?

Answer 37

frontal eye fields

Question 38

In a horizontal eye movement, what two muscles and thereby what two nerves need to work together?

Answer 38

medial and lateral rectus; CN III and VI

Question 39

The ________ _______ connect the abducens nucleus and the oculomotor nucleus, and is critical for coordinate gaze.

Answer 39

ascending MLF

Question 40

The ascending MLF is critical for what reflex?

Answer 40

vestibulo-ocular

Question 41

The descending MLG is the _______ __________ tract.

Answer 41

medial vestibulospinal tract

Question 42

The aMLF connects the vestibular nuclei (CN VII) to the nuclei of what three CN?

Answer 42

III, IV, and VI

Question 43

What are the three types of eye movements?

Answer 43

1. saccades 2. pursuit 3. vestibule-ocular reflex

Question 44

What are the two types of saccades?

Answer 44

1. volitional | 2. reflexive

Question 45

What are the 3 types of volitional saccades?

Answer 45

1. anti-saccade 2. memory saccade 3. predictive saccade

Question 46

Information for reflexive saccades comes from the _______ _______.

Answer 46

superior colliculus

Question 47

Before moving ones gaze, both reflexive and volitional saccades must synapse were?

Answer 47

paramedian pontine reticular formation

Question 48

A saccade to the left comes from the _______ side of the cortex.

Answer 48

right

Question 49

Pursuit to the left comes from the ______ side of the cortex.

Answer 49

left

Question 50

Vertical gaze requires coordination of what two nerves?

Answer 50

CN III and IV

Question 51

Where is the vertical gaze center located?

Answer 51

rMLF pretectal area

Question 52

Horizontal gaze centre in the _____, vertical gaze center in the _______.

Answer 52

pons; midbrain

Question 53

________ gaze = eyes move in different directions.

Answer 53

disconjugate

Question 54

What two things does disconjugate gaze include?

Answer 54

1. convergence | 2. divergence

Question 55

A dilated pupil may indicated ________ pathology.

Answer 55

parasympathetic

Question 56

A constricted pupil may indicated a __________ pathology.

Answer 56

sympathetic