E1 Flashcards

1
Q

Bells palsy is from paralysis of what nerve?

A

Facial Nerve, CN 7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the clinical presentation of Bell’s palsy? (6) Explain why each symptom is caused.

A

Unilateral drooping of facial muscles (upper and lower face) due to motor loss from facial nerve damage. Drooling/difficulty chewing, due to paralyzed buccinator. Inability to close eye, due to paralysis of orbicularis oculi. Loss of taste to anterior 2/3 of tongue, due to facial sensory innervation. Pain in/behind ear, due to sensory innervation. Hyperacousia, due to paralyzed stapedius muscle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Bell’s palsy is a ______ motor neuron disorder

A

Bell’s palsy is a lower motor neuron disorder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

An upper motor neuron lesion of CNVII would result in what clinical presentation? What could cause this to occur?

A

Paralysis of lower facial muscles - Corticol stroke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What innervates the outer ear?

A

CN V, VII, IX, X

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Paralysis of orbicularis oculi can result in what outcome?

A

Damage to cornea of eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Typically, skeletal muscle of the middle ear act to dampen sound. What clinical condition is caused by the inability to do this?

A

Hyperacousia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the somatic sensory innervation of the face?

A

Mainly trigeminal (CN-V) with V1 doing the forehead + bridge of nose (opthalmic), V2 doing maxillary region, and V3 doing Mandibular. The outer ear is also 7, 9, 10.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is unique about the veins of the face?

A

They have no valves (or few and variable)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain venous drainage of the face

A

Supraorbital and Supratrochlear vein, Facial Vein anastomse with Ophthalmic vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Infections can easily spread from the face to the brain. Why? What clinical thing will likely occur if this happens.

A

The cavernous sinus anastomoses with Facial and Ophthalmic, and since there are no valves, prolonged infection can spread to Cav. sinus.

Diplopia (blurred vision) occurs because the cranial nerves pass through cavernous sinus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Cleft lip is formed from a failure of what two processes to to fuse?

Where does this occur?

A

Medial Nasal Process and Maxillary Process.

Occurs at the philtrum of lip

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Occulomotor parasympathetics leave the brain stem at the ______ and go to ______ to produce and effect on _____ and ______

A

Occulomotor parasympathetics leave the brain stem at the MIDBRAIN and go to CILIARY GANGLION to produce and effect on CILIARY MUSCLE and SPHINCTER PUPILLAE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The paraympathetics of the facial nerve leave at the _______ and regulate (5) things

A

Leave at the medulla. Regulate - Lacrimal Gland, Mucous glands of oral + nasal cavities. Palate. Submandibular gland. Sublingual gland.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The zygomatic arch is composed of…

A

Zygomatic bone, Zygomatic Process (maxillary bone), Zygomatic process (temporal bone)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Name the 5 layers of the scalp and the clinical significance to the layers

A

Skin, Connective tissue, epicranial Aponeurosis, Loose areolar tissue, periosteum

Clinical: infection can easily spread through the loose areolar layer, which is deep to the epicranial aponeurosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What goes through the anterior and posterior ethmoidal formanina? What are these things branches off?

A

The ant and post. ethmoidal N, A, and V.

V1 and ophthalmic artery and vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

An obstructed Nasolacrimal duct will cause tears to flow..

What can be done to stop this?

A

Onto the face.

Surgically open the duct.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Obstruction or infection of the sebaceous gland (subcutaneous layer) of the eyelid is called?

A

Stye or Horde’olum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Obstruction of the tarsal/Meibomian gland (at the tarsal plate) of the eyelid is called?

A

Chalazion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the flow of tears?

A

Lacrimal Gland -> medial across eye to lacrimal puncta, Lacrimal canaliculu –> Lacrimal sac –> Nasolacrimal duct –> inferior meatus of nasal cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What innervates the lacrimal gland?

A

Facial nerve (CN-VII), Parasympathetics. Pterygopalatine ganglion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

In normal vision at a distance, describe the state of the suspensory ligaments, ciliary muscles, and lens.

A

Ciliary muscles are relaxed, suspensory ligaments are taut, lens is flat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

In near vision, describe the state of the ciliary muscles, suspensory ligaments, and lens.

A

Ciliary are contracted, Suspensory are relaxed, lens is thick.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What nerve is responsible for control of the ciliary muscles? Where are they located anatomically? What are they a branch and what kind of nerve is it.

What other muscle is innervated by the the short ciliary nerve? Clinical effect?

A

Short ciliary nerve. Located lateral to the optic nerve. It is parasympathetic control from CN 3.

Constrictor pupillae –> Mydriasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Constrictor pupil is under what nerve control? From what nerve?

A

Parasympathetics, CN3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Dilator pupil is under what nerve control?

A

Sympathetics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the actions of the superior rectus?

A

Raise, adduct, medial rotate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the actions of the inferior oblique?

A

Raise, abduct, laterally rotate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is a symptom of damage to the abducens nerve?

A

Medial strabismus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Draw the eye movement diagram from Zill’s notes and explain it.

A

Jus do it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

A patient with CN-4 damage will have trouble with what daily task?

A

Looking down / walking down stairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What compensatory mechanism will patients with CN-4 damage do?

A

Tilt head to opposite side.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Damage to the occulomotor nerve produces what 3 clinical presentations and why?

A

Lateral strabismus (due to paralyzed medial rectus), Ptosis (paralyzed lev. palpebrae superioris), Mydriasis (pupillary constrictor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Long ciliary nerves are branches of ___ and travel ___ to the optic nerve.

A

V1 and medial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Parasympathetics do not go to the…

A

Body wall ( skin / peripheral blood vessels)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What muscle attached to hair on the skin is only innervated by sympathetics?

A

Arrector Pilae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the 3 symptoms of Horners syndrome? And what causes this condition.

A

Miosis, Ptosis, Anhydrosis

Damage to the sympathetic pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What area of the brain regulates sympathetic control? What does this area send signals to?

A

Hypothalamus, sends signals to the pre-ganglionic neurons in the spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Where does sympathetic outflow occur in the spinal cord?

A

Thoracic and lumbar levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Describe the flow of sympathetic effect for a smooth muscle of eye.

A

Hypothalamus sends signal down spine, comes out t1, t2. Ascends up the superior cervical ganglion. Postsynaptic fibers join plexus on internal carotid artery. Muscle contracts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is the boundary between the oral cavity and pharynx?

A

Palatoglossal arch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is the order of innervation of the branchial arches?

A

First arch, second arch, third arch, fourth arch, 6th arch.
–5 (V3), 7, 9 , 10, 11.–

Note: the 5th arch doesn’t do anything

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

The first branchial arch innervates what muscles?

A

Anterior belly of digastric, mastication muscles, mylohyoid, tensor tympani, tensor palati

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

The second branchial arch innervates what muscles?

A

Facial expression, stylohyoid, posterior belly of digastric, stapedius

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

The third branchial arch innervates what muscle?

A

Stylopharyngeus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

The fourth branchial arch innervates what muscles?

A

All of pharynx (except stylopharengeous), all of larynx, all of palate (except tensor palati)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

The sixth branchial arch innervates what muscles?

A

Sternocleidomastoid, trapezius

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

The first branchial pouch forms what?

A

Auditory tube, tympanic cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

The second branchial pouch forms what?

A

Palatine tonsils ( t for two and tonsil)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

The third branchial pouch forms what?

A

Parathyroid glands, thymus gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

The 4th branchial pouch forms what?

A

Superior parathyroid glands, and C-cells (calcitonin) of thyroid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

The most common branchial cleft cyst is the..

A

Tract to palatine tonsils, the second branchial cleft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

In thyroid development a piece of thyroid can remain above the structure. This is called..

A

A pyramidal lobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Torticollis is what? What is the clinical presentation?

A

Contracture of the sternocleidomastoid. Head points in opposite direction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is the clinical nerve test for CN-11?

A

Shrug shoulders

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What are the compartments of the neck? (3)

A

Prevertebral, pretracheal, carotid sheath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What space in the neck has potential for obstructing an airway / spreading infection?

A

Retropharyngeal space – a Retropharyngeal abcess

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Why can’t children localize pain when an ear ache is happening?

A

It is innervated by the CN 9, which is visceral sensory.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What is an infection of the middle ear called?

A

Otitis media

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Piercing the eardrum can cause what unique clinical presentation? Due to damage of what nerve?

A

Loss of taste to anterior 2/3 of tongue due to damage to chorda tympani nerve.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What muscle increases pitch of vocal cords? What is the movement of the cords?

A

Cricothyroid - tenses vocal fold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What muscle decrease pitch of vocal cords? What is movement of the cords?

A

Thyroarytenoid - relaxes vocal fold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What muscle closes the vocal cords by sliding?

A

Arytenoideus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What surgery is at risk of damaging the recurrent laryngeal nerve, and what is the clinical result if it is damaged.

What is the recurrent layrngeal nerve a branch off of?

A

Thyroid surgery. Permanent hoarse voice.

Vagus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What is the lymph drainage of the larynx?

A

Above true vocal folds - superior deep cervical nodes

Below true vocal folds - inferior deep cervical nodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

In anaphylactic shock, insert tube through cricothyroid membrane. What is the advantage of this?

A

Less bleeding than a tracheotomy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What is the “first popcorn”

A

Valleculae. In the oropharynx.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What is the “second popcorn”

A

Piriform recess. Lateral to inlet of larynx (laryngopharynx)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

The pharynx constrictor muscles are innervated by what nerve?

A

Vagus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What is a crossed extension reflex?

A

Excite extensors and inhibit flexors in opposite leg. Step on nail, one leg gets flex response (side of stimulus) and the support leg is extended to hold body.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

A tendon type of biceps will do …

A

Excite synergistic muscles and produce opposite effect on antagonist muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

Some reflexes change after upper motor neuron lesion, what is one?What is the response?

A

Babinski. Will extend and fan toes if UMN lesion present.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What is the clasped knife reflex response? What person would have this?

A

Inhibit synergistic muscles, excite antagonist. A person with an UMN lesion would do this.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What is the physiological purpose to a clasped knife reflex?

A

To limit tension in muscle.

76
Q

What kind of neurons are in short ciliary nerves?

A

Post ganglionic nerves

77
Q

Corneal reflex is what nerve / muscle combination

A

Long ciliary nerves (V1) and orbicularis oculi.

CN V to CN VII

78
Q

Pupillary light reflex is what two nerves working together?

A

CN 2 and CN 3

79
Q

Gag reflex is what two nerves working together?

A

CN 9 to CN 10

80
Q

Cell bodies of the trigeminal nerve are in what ganglia?

A

Semilunar (Trigeminal) Ganglia

81
Q

Cell bodies of sensory neurons of facial nerve are in what ganglia?

A

Geniculate Ganglia

82
Q

Sympathetic ganglia are located ____ to the vertebra

A

Close

83
Q

Parasympathetic ganglia are located ____ to the vertebra

A

Far, close to target organ

84
Q

What cranial nerves have sympathetic divisions?

A

CN 3, 7, 9, 10

85
Q

What are the visceral sensory innervations of the pharynx?

A

Nasopharynx is 7, Oropharynx 9, Laryngopharynx 10

86
Q

What are the three cranial nerves that sense for taste and where are they located?

A

Facial (ant 2/3 of tongue), Glossopharyngeal (post 1/3 of tongue), Vagus (anterior to epiglottis)

87
Q

The pterion is at the junction of what bones?

A

temporal, sphenoid, parietal, frontal bones

88
Q

Why is the pterion clinically significant?

A

The middle meningeal artery overlies it, and fracture at the pterion can result in a epidural hematoma

89
Q

The lesser occipital nerve is from what portion of the spine?

A

C2 ventral ramus

90
Q

The greater occipital nerve is from what portion of the spine?

A

C2 dorsal ramus

91
Q

What passes through the cavernous sinus?

A

Internal Carotid Artery, CN 3, 4, V1 + V2, 6

92
Q

What are the layers of the cornea from outer to inner?

A

Coreal epithelium, Bowmans layer, Stroma, Descements Membrane, Endothelium

93
Q

The corneal epithelium of the eye makes up what type of epithelium?

A

Stratified squamous

94
Q

What makes the aqueous humor of the eye?

A

Ciliary Body

95
Q

What are the pigmented layers of the ciliary body?

A

Superficial (not pigmented) and the Deep cells (pigmented)

96
Q

What reabsorbs the aqueous humor?

A

Sclera Venous Sinus

97
Q

Aq. humor flows from ______ to the ______ via the pupil

A

Posterior chamber to the anterior chamber

98
Q

What is glaucoma?

A

Damage to the optic nerve

99
Q

Where are the epithelial cells of the iris?

A

In the posterior. There are two layers of pigmented cuboidal epithelial cells.

100
Q

What artery provides blood to the lens?

A

None, it is avascular.

101
Q

Describe the flow of the lens cells throughout time.

A

Simple cuboidal cells on the surface lose nuclei and organelles and go to the center of the lens. They continue to pack with age and the center is packed with crystallins

102
Q

What area has the highest visual acuity in the retina?

A

Fovea centralis, which is in the center of the Macula lutea

103
Q

Describe the flow of information in the retina processing schematic.

A

Light comes in, hits back of retina, fires rods and cones. This information goes to the bipolar cells, which sends information to the ganglion cells. The axons go out as the optic nerve.

104
Q

What is the vascular layer of the eye?

A

Choroid

105
Q

Where do the blood vessels enter eye? What is unique about this spot?

A

Optic disc. It is the blind spot

106
Q

In eye development, what comes from the surface ectoderm?

A

The lens and the cornea

107
Q

In eye development, what comes from the mesenchyme?

A

Choroid, sclera, vitreous body

108
Q

What does the auditory tube connect?

A

Middle ear cavity to pharynx

109
Q

What is the functional organ of the cochlear duct? Explain its function

A

Organ of corti: Hair cells in a basilar membrane that project into a tectorial membrane. Endolymph moves the basilar membrane and moves the hair cells. Displacement of the hair cells initiates nerve signals of CN VIII

110
Q

What are the three “tubes” of the cochlea and fluid is present in each one.

A

Scala vestibuli, Scala media (cochlear duct), Scala tympani

Endolymph in scala media, perilymph in the other two

111
Q

The utricle and saccule are responsible for what?

A

Part of vestibular system. Utricle and saccule are for linear acceleration.

112
Q

What is the semicircular canals purpose? What is the “functional organ”

A

For detecting rotational movement.

Crista ampullaris is the functional organ.

113
Q

Explain the process of hearing.

A

Sound enters through the external auditory meatus and vibrates the tympanic membrane. This moves the malleus, then incus, then stapes. The stapes vibrates the oval window which moves perilymph in scala vestibuli and scala tympani. This vibrates the endolymph in the scala media, which uses the organ of corti to send the nerve signals.

Excess sound moves out the round window and dissipates.

114
Q

What are the five branches of the facial nerve? Where does it branch?

A

Branches at the Parotid gland. Temporal, Zygomatic, Buccal, Mandibular, Cervical.

115
Q

Name the branches of the external carotid.

A

Superior Thyroid, Ascending Pharyngeal, Lingual, Facial, Occipital, Posterior Auricular, Maxillary, Superficial Temporal

116
Q

Where does the superior petrosal sinus drain?

A

Transverse sinus

117
Q

Where does the inferior petrosal sinus drain?

A

Internal jugular

118
Q

Where is cerebral spinal fluid made? Where is it absorbed?

A

Made at the choroid plexus. Absorbed at the arachnoid villi.

119
Q

A subarachnoid hematoma can be caused by what type of aneurysm?

A

Berry

120
Q

What causes a subdural hematoma? What shape would it appear on CT?

A

A tear in the bridging vein. Crescent shaped.

121
Q

What causes a epidural hematoma? What shape would it appear on CT?

A

Middle meningeal artery lesion at pterion. It would appear lens shaped.

122
Q

What prevents excess rotation of eyes?

A

Medial and Lateral check ligaments

123
Q

Ophthalmic A. has 4 artery branches, what are there?

A

Posterior ciliary A. (long and short), Central artery of retina, Supraorbital, Supratrochlear

124
Q

What provides blood for the photoreceptors and choroid?

A

Posterior ciliary arteries

125
Q

What provides blood for the neural retina?

A

Central artery of retina. This pierces the optic nerve

126
Q

Occlusion of the central artery of retina can result in? What causes this?

A

Blindness in one eye. Carotid artery occlusion.

127
Q

What is papilledema? What can result from this?

A

Engorgement of retinal veins at optic disc. Vision can be impacted

128
Q

What vertebral levels make up the ansa cervicalis?

A

C2-C4

129
Q

What ligaments prevent excess rotation of head?

A

Alar check ligaments

130
Q

What are the four suboccipital muscles and what are their actions?

A

Rectus Capitis Posterior Major, Rectus Capitis Minor, Obliques Capitis Superior, Obliques Capitis Inferior

Extend + Rotate, Extend, Extend, Rotate

131
Q

The pharynx connects to what muscle?

A

Buccinator. Superior constrictor inserts there.

132
Q

Where do the constrictors of the pharynx insert?

A

Pharyngeal raphe

133
Q

Sensory of pharynx is done by what?

A

Nasopharynx - 7. Oropharynx - 9. Laryngopharynx 10.

134
Q

What are renshaw cells?

A

They are interneurons that receive excitatory inputs from recurrent branches of motor neurons and make inhibitory synapses upon the same motor neurons. They limit motor neuron firing.

135
Q

What effect does a convex lens have on light?

A

Converges the light rays

136
Q

A concave lens has what effect on light?

A

Diverges light

137
Q

A cylindrical lens has what effect on light?

A

Light is refracted towards or away from a line

138
Q

What is focal length? What is its relation to eyesight?

A

Distance behind a convex lens at which parallel light rays converge.

This length is what we want to equal the distance from lens to retina.

139
Q

What is the relationship between focal length and the closeness of an object?

What can the lens do to correct this issue?

A

The closer the object, the longer the focal length. This is because light rays from less than 20 feet away are not parallel, they are diverging

The lens can increase its thickness (convexity) and adjust the focal length

140
Q

A diopter is equal to..

Describe the relationship of diopter, focal length, and lens convexity (thickness)

A

1m/focal length (m)

As diopter increases, the focal length decreases, lens thickness increases.

141
Q

A negative diopter value means what type of lens?

A

Concave lens

142
Q

A positive diopter value is what type of lens?

A

Convex lens

143
Q

Where does 2/3 of refractive power of the eye come from?

Why?

A

The anterior surface of cornea.

The refractive interface between air and ant. surface of cornea is the greatest

144
Q

What three things are unavoidable in life?

A

Death, Taxes, and Presbyopia

145
Q

What does pupil diameter impact? (besides amount of light that enters the eye).

What does this mean? How does pupil diameter change this?

A

Depth of focus (depth of field)

It describes the range in which objects remain in focus.
A small pupil provides long depth of focus, large pupil is short depth of focus.

146
Q

What is the argyll robertson pupil? What is it associated with?

A

Bilateral small pupils that constrict when a patient focuses on near objects, but does not constrict when exposed to bright light. Strongly associated with neurosyphyllis

147
Q

Explain emmetropia, myopia, and hyperopia.

A

Emmetropia is perfect eye sight. Focal length matches the length of eyeball and lands on retina.

Myopia (nearsight) is caused by a long eyeball (or strong lens). The focal length is too short and converges before the retina. Ciliary muscles cannot be relaxed anymore than they are, so distant object cannot be seen.

Hyperopia (farsight) is caused by a short eyeball (or weak lens). The focal length is too long and converges behind retina. To compensate, ciliary muscles contract to increase refraction.

148
Q

What diopter (neg or pos) goes with hyperopia and myopia? What type of lens do they need in their glasses?

A

Myopia is negative, with concave lens. Hyperopia is positive with convex lens.

149
Q

What is the cause and result astigmatism? What kind of lens is needed?

A

It is caused by an uneven curvature of the cornea. Light is being focused at different levels in the vertical and horizontal planes.
They must use cylindrical lens.

150
Q

What cells in the eye fires action potentials?

A

Ganglion cells only

151
Q

What is the difference (in terms of number of retinal cells) between the peripheral retina and the fovea?

A

The peripheral retina has many photoreceptors that converge to one ganglion cell. This allows high sensitivity but low spatial resolution.

The fovea has about a 1:1 ratio. This allows low sensitivity but high spatial resolution.

152
Q

What keeps photoreceptors depolarized in the dark? What NT are photoreceptors releasing in the dark.

A

High levels of cGMP.

They constantly release glutamate.

153
Q

What is the pathway for phototransduction?

A

Light shines on the receptors. 11-cis retinal becomes trans retinal. Opsin undergoes conformational change and activates transducin (G-protein). This activates PDE, which degrades cGMP to GMP. CNG channels close, and the membrane hyperpolarizes. VGCa channels are increased. NT release decreases proportionally to light intensity.

154
Q

What molecule absorbs the photons? What is this comprised of?

A

Rhodopsin (Retinal + Opsin)

155
Q

What is a major role of opsin with respect to retinal?

A

It binds retinal, which stimulates G-proteins. And it tunes the retinal to the specific light spectrum

156
Q

What conformational change does retinal undergo? What does this change trigger?

A

11-cis retinal to trans retinal. This triggers a conformational change in opsin.

157
Q

What part of the phototransduction in rods allows one photon to produce a signal.

A

Signal amplification

158
Q

On a tuning curve plot with frequency on X-axis and threshold intensity on Y-axis, where is the receptor most sensitive?

A

At the lowest point on the graph

159
Q

On a tuning curve plot where sensitivity is plotted against wavelength, where is the receptor most sensitive?

A

At the peak

160
Q

Rank the 3 colors in terms of length of wavelength from short to longest

A

Blue, Green, Red

161
Q

Each cone has only one type of this compound.

A

Opsin

162
Q

What is dyschromatopsia?

A

Color blindness, commonly caused by loss of red or green. Sex-linked in males (X chrom)

163
Q

Explain scotopic, mesopic, and photopic vision

A

Scotopic is only rods. Mesopic is both (but rods are not fully saturated) and phototopic is only cones (fully saturated)

164
Q

What type of glutamate receptors does On-center bipolar cells have?

A

Metabotropic (MGlu6)

165
Q

What type of glutamate receptors does off-center bipolar cells have?

A

Ionotropic

166
Q

Explain the rod pathway.

A

The rod-bipolar synapse is inhibitory. Rod BP cells synapse onto amicrine cells. Amicrine synapse onto on and off center cone BP cells. Inhibitory synapse onto OFF center cone bipolar cells, excitatory synapse onto ON center cone bipolar cells.

167
Q

What is the name of the clinical disease from rod issue? What is the cause?

A

Melanoma-associated retinopathy. They get an antibody against MGlu6 (paraneoplasia).

168
Q

What disorder causes a total loss of night vision?

A

Congenital stationary night blindness

169
Q

Compare and contrast M type and P type ganglion cells.

A

M type have smaller abundance, but have a larger receptive field size (can be stimulated from further away). They have fast conduction velocity with no color preference in wavelength. They detect movement.

P type have high abundance and have small receptive field. They do not have as fast of a conduction velocity and prefer color. They detect fine detail and form.

170
Q

What is a kinocilium? What movements of it produce what effects?

A

It is the long hair cell. Moving of other hair cells towards the kinocilium results in depolarizing. Moving of hair cells away from the kinocilium is hyperpolarizing.

Moving perpendicular to it results in no effect.

171
Q

What kind of channels open when hair cells bend?

A

Mechanically gated CATION channels. K+/Ca+2 permeable.

172
Q

Describe the differences between endolymph and perilymph.

A

Endolymph has HIGH K+ and LOW NA+ - abnormal body fluid

Perilymph has LOW K+ and HIGH NA+ - normal body fluid

173
Q

What direction is the driving force for K+ in the hair cell system?

A

Inward across the apical membrane. High to low, like always.

174
Q

Depolarization of the basolateral membrane opens what kind of channels? What follows this?

A

VGCa, which triggers NT release.

175
Q

Do hair cells always release Glu at rest? Bending of which way will increase/decrease release?

A

Yes they do. Bending towards the kinocilium will increase, being away will decrease.

176
Q

Explain the changing of hair cell orientation in the otolith organs.

A

They do not change much across the maculae, until the striola, where there is a 180 degree change.

177
Q

The utricle and saccule are most sensitive to acceleration in what planes?

A

Utricle - horizontal

Saccule - sagittal

178
Q

Hair cells within each ampulla share the _____ orientation.

A

Hair cells within each ampulla share the same orientation.

179
Q

Explain the pairing associations between the semicircular canals

A

Left horizontal with right horizontal. Left anterior vs. right posterior. Right anterior vs. left posterior

180
Q

Do semicircular canals respond to velocity?

A

No. And the output can adapt to a constant velocity

181
Q

The pinna allows us to localize sound in what plane?

A

Vertical

182
Q

What secretes endolymph in the cochlea?

A

Stria vascularis

183
Q

Explain basilar membrane of the cochlea functioning at different frequencies (High, medium, low)

A

High - large amplitude at base initially, but dissipates
Low- sound travels to apex without dying out
Medium - somewhere in between

184
Q

Hair cilia can bend because the tectorial and basilar membrane share different _____ in different axes

A

Pivot points

185
Q

An upward movement of the basilar membrane is a _____ force, while the downward movement is a _____ force

A

Depolarizing, hyperpolarizing

186
Q

What is the difference between sensory neural deafness and conduction deafness.

A

Sensory neural deafness is an issue with the inner ear, and conduction deafness is other area of ear.