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Flashcards in Unit 2 Deck (40)
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1
Q

CN I found in olfactory epithelium lining ….

A

Superior part of nasal cavity

Sup. Nasal concha only, not middle or inf.

2
Q

T/F. Olfactory N are myelinated

A

F. Unmyelinated but they are covered by schwann cells

3
Q

Olfactory tract fibers split into medial and lateral olfactory striae at the ______________________.

A

Anterior perforated substance

4
Q

Medial stria fibers cross midline via the

A

Anterior commissure

5
Q

Lateral stria fibers carry info to the:

A

Primary olfactory cortex; on the medial aspect of the temporal lobe

Periamygdaloid and prepiriform area
–including the uncus (34) and entorhinal area (28)

6
Q

Alternative olfactory pathways

A

Terminal nerve & Vomeronasal nerve

7
Q

Terminal nerve pathway

A

From receptors on nasal septum (autonomic)

8
Q

Vomeronasal nerve pathway

A

Poorly developed in humans

Important for tracking prey

9
Q

3 layers of the eye

A
Outermost layer = fibrous tunic 
   Sclera, cornea
Middle layer = vascular tunic
   Ciliary body, iris, choroid
Innermost layer = retina 
   10 layers
10
Q

Retina layers

A
  1. Pigmented layer
  2. Photosensitive outer segments of rods and cones
  3. External limiting membrane
  4. Outer nuclear layer (rod/cone cell bodies)
  5. Outer plexiform layer (synapse on bipolar cells)
  6. Inner nuclear layer (bipolar cell bodies)
  7. Inner plexiform layer (synapse on ganglion cells)
  8. Ganglion cell layer (bodies)
  9. Nerve fiber layer (retinal gang axons -not myelinated)
  10. Internal limiting membrane (separates retina from vitreous body)
11
Q

Cones -3 types and where concentrated

A

Red, blue, green

More concentrated toward center of retina (fovea centralis = point of clearest vision)

12
Q
Ganglion cell axons (nerve fiber layer) -> 
\_\_\_\_\_\_\_\_\_ ->
Optic nerve ->
\_\_\_\_\_\_\_\_\_->
Optic chiasma
A
  1. Optic disc

2. Optic canal

13
Q

Are optic nerve axons myelinated?

A

Yes.

Not myelinated inside eye. Axons leave eye at optic disc and become myelinated and form optic nerve.

14
Q

What cells form CNS myelin

A

Interfascicular oligodendrocytes

15
Q

In the optic chiasma, fibers from which side of the retina cross?

A

Medial (nasal) side cross

Lateral (peripheral) side do not cross

16
Q

Optic tract travels around cerebral peduncles and fibers synapse on 1 of 3 nuclei or termination:

A

1: Majority synapse in LATERAL GENICULATE BODY and are relayed to cerebral cortex in the occipital lobe (BDMN 17)
2: Superior colliculus - info relayed to tectospinal tract (SCM & Traps)
3: Pretectal nucleus of midbrain - fibers deal with light reflexes

17
Q

Visual Reflexes

A

Direct and Consensual light reflexes
Accommodation reflex
Corneal reflex
Convergence

18
Q

Direct and consensual light reflexes

A

Flashlight in eye to see both eyes contract

19
Q

Accommodation reflex

A

Switching focus

20
Q

Corneal reflex

A

Touch eye with cottonball

21
Q

Convergence

A

Cross eyes

22
Q

Oculomotor nuclei receive input from

A
  1. BDMN 8
  2. Superior colliculus
  3. Medial longitudinal fasciculus
23
Q

Somatic nuclei of origin, located in periaqueductal gray matter

A

Oculomotor nuclei

24
Q

Oculomotor axoxs travel anteriorly through the Red nucleus and exit CNS in (apparent origin)

A

The interpeduncular fossa (into the cistern)

25
Q

Oculomotor nerve enters eye socket and splits into sup and inf rami, supplying …

A

Superior ramus supplies superior rectus and levator palpebral superioris

Inferior ramus splits into 3 branches:
Medial branch supplies medial rectus
Central branch supplies inferior rectus
Lateral branch supplies inferior oblique

26
Q

Nerves leaving the ciliary gangion also carry sypathetic and somatic sensory fibers picked up from …

A

The opthalmic nerve V1 passing through the ganglion without synapsing

27
Q

What parts of the brain send axons to the trochlear nucleus?

A

BDMN 8, Sup colliculus, and Medial longitudinal fasciculus

28
Q

Abducens nucleus is located…

A

In the caudal part of the pons, at the floor of the rhomboid fossa

29
Q

Abducens nerve receives info from

A

Same as CN III & IV

BDMN 8, SC, MLF

30
Q

What is Strabismus

A

Eyes not pointing at the same thing

31
Q

Internal Strabismus

A

Eyes cross (converge)

32
Q

External strabismus

A

Eyes directed away from each other (diverge)

33
Q

Diplopia

A

Double vision

34
Q

Ptosis

A

Eyelid droops due to weakness of levator palpebrae superioris. CN III lesions may be the cause

35
Q

Oculomotor paralysis

A

External ophthalmopegia:

  1. External strabismus; effected eye deviates down and out
  2. Diplopia
  3. Ptosis

Internal ophthalmopegia:

  1. Inability to constrict pupil
  2. Loss of light reflex
  3. Loss of accommodation reflex
36
Q

Etiologies of oculomotor paralysis

A

Uncal herniation,
PCA anneurysm (post cerebral aneurysm)
Diabetes

37
Q

Trochlear paralysis

A

Internal strabismus. Inability to look down (slight converging when looking down)

Rare

38
Q

Abducens paralysis

A

MC

Internal strabismus + displopia

39
Q

Internuclear ophthalmoplegia

A

Lesion to MLF

Nystagmus when abducting eye

40
Q

Practice table 1 pg 183

A

Do it nowwww