7/22 Part One (Cranial Dvlpmt. & Innerv; Cranial Nerve overview; Cranio-facial muscltr.) Flashcards Preview

Bio 223 > 7/22 Part One (Cranial Dvlpmt. & Innerv; Cranial Nerve overview; Cranio-facial muscltr.) > Flashcards

Flashcards in 7/22 Part One (Cranial Dvlpmt. & Innerv; Cranial Nerve overview; Cranio-facial muscltr.) Deck (55):
1

Very basically, what are placodes?

neural tissue that will contribute to special senses

2

The neural plate becomes the DHNT, the neural fold becomes neural crest, but what happens to the part that is lateral to both of those?

it becomes placodes
(still neural tissue but NOT neural crest or neural plate)

3

The 3 placodes that we need to "focus" on:

1 = Olfactory (nasal) placode
2 = Optic (lens) placode
3 = Otic (ear) placode

4

What does the nasal placode start to become...

nerve fibers

5

Where do the "nerve fibers" of the olfactory placode pass through?

cribiform plate of the ethmoid bone

6

What does the second placode become? How?

-It becomes the lens of the eye
-It sinks below the surface of the skin and an outgrowth of the brain wraps around it

7

What does the "outgrowth" that wraps around the lens become?

the retina

8

The inner ear starts out as what? Then what does it turn into?

Starts out as a lens
Turns into a fluid filled sac

9

With the otic placode, the fluid filled sac has hairs that are sensitive to what?

movement
vibrations (sound) comes into the ear and moves the fluid which moves the hairs and allows you to hear stuff

10

Movement of the fluid causes movement of the hair and leads to the ability to hear, but what else?

balance

11

Vestibulocochlear nerve is also called __________ but is usually called the first name because it refers to both balance AND hearing.

auditory nerve
(only refers to hearing)

12

The vestibular apparatus and cochlear apparatus are derived from...

the otic placode

13

What is a somitomere?

smaller portion/division of somites; takes 2 to make one somite

14

Head (cranial) somites can be divides into how many general regions? What are they?

2
Pre-otic and post-otic

15

Pre-otic has how many somites?
Post-otic has how many somites?

Pre: 3 somites
Post: the rest (4-5) of the somites

16

The first 3 somites are associated with the...

developing eye

17

The post-otic somites represent...

the branchial/pharyngeal/visceral arches

18

The sclerotomes of the post-otic somites form what?

the floor of the braincase
(chondocranium)

19

Since chondrocranium comes from the sclerotome of somites, it is homologous to...

the vertebrae

20

When the CNS leaves the protection of the vertebral column, what does it now lack?

meninges

21

What does the myotome of the post-otic somites become?

the muscles of the tongue

22

What does the myotome of the pre-otic somites become?

the muscles that move the eye

23

Which cranial nerve is associated with the first somite?

CN 3

24

Which cranial nerve is associated with the second somite?

CN 4

25

Which cranial nerve is associated with the third somite?

CN 6

26

The neural crest CANNOT form what?

musculature

27

Since the muscle can't come from neural crest, where does it come from?

somites

28

Once the somite musculature gets dragged down onto the arches and becomes associated with branchial arches, you can no longer call it somatic musculature. You now have to consider it...

branchial musculature

29

Which nerve is associated with the mandibular arch?

CN 5

30

Which nerve is associated with the hyoid arch?

CN 7

31

Which nerve is associated with the 3 arch?

CN 9

32

Which nerve is associated with the rest of the arches?

CN 10

33

For the branchial arches, they drag down the myotomes in order to create the branchial musculature. But before that, what did the branchial arches had to have?
What does this mean?

sensory innervation
they have BOTH sensory and motor!

34

So the types of nerves for each....
Branchial arches:
Placodes:
Somites:

Branchial arches: both
Placodes: sensory
Somites: motor

35

Nerves..
Number 1:
Type:
Function:
Foramen:

Olfactory
Sensory
Smell
Cribiform plate of ethmoid

36

Nerves...
Number 2:
Type:
Function:
Foramen:

Optic
Sensory
Vision
Optic foramen (optic canal)

37

Nerves...
Number 3:
Type:
Function:
Foramen:

Oculomotor
Motor
Eye movement
Superior orbital fissure

38

Muscles of the oculomotor nerve:

Superior rectus muscle
Medial rectus muscle
Inferior rectus muscle
Inferior oblique muscle

39

Not all eye muscles are in the oculomotor nerve. Where are the others?

Superior oblique muscle = Trochlear nerve
Lateral rectus muscle = Abducens nerve

40

Nerves...
Number 4:
Type:
Function:
Foramen:

Trochlear
Motor
Superior oblique
Superior orbital fissure

41

Cranial nerves that carry parasympathetic innervation out of the skull (covered with meninges then NOT covered any more) are...

CN 3
CN 7
CN 9
CN 10

42

The actual fibers of cranial nerve 4 come out _________ even though cell bodies are in the ________ aspect.

dorsally
ventral
(they are originally ventral)

43

Nerve 5:
V1 =
V2 =
V3 =

Trigeminal
V1 = ophthalmic (sensory; SOF)
V2 = maxillary (sensory; rotundum)
V3 = mandibular (both; ovale)

44

Nerves...
Number 6:
Type:
Function:
Foramen:

Abducens
Motor
Lateral rectus
Superior orbital fissure

45

Nerves...
Number 7:
Type:
Function:
Foramen:

Facial
Both
Facial expression, taste, lacrimal, nasal, salivary glands
Enter = internal auditory meatus
Exit = stylomastoid foramen

46

Nerves...
Number 12:
Type:
Function:
Foramen:

Hypoglossal
Motor
Tongue
Hypoglossal canal

47

Details on sensory aspect of V1 (ophthalmic)...

-almost wholly sensory: eyeball, lacrimal gland, conductive, part of nasal mucosa, form brow ridge

48

V1 carries what kind of parasympathetic fibers? From where to where?

Carries postganglionic parasympathetic fibers from pterygopalatine ganglion (preganglionic from CN 7) to lacrimal gland

49

V1 also carries sympathetic fibers, but for what?
Where do they synapse?
Where do the postganglionic fibers go?

-dilator papillae from upper thoracic levels
-cranial cervical ganglion
-they reach the ophthalmic nerve via branches of internal carotid artery

50

Details on sensory aspect of V2 (maxillary)...

-almost whole sensory: lower eyelid down to upper lip, gums and teeth; cheek; nose, palate, & pharynx (partial

51

What kind of fibers does V2 carry? From where to where?

Carries postganglionic parasympathetic fibers from pterygopalatine ganglion (CN 7) to lacrimal and nasal glands

52

Details on sensory AND motor aspects of V3 (mandibular)...

-Sensory: lower jaw region, including teeth
-Motor nerve to muscles of mandibular arch: masseter, temporalis, medial & lateral pterygoids, mylohyoid, tensor tympani, anterior digastric, and tensor veli palatini

53

What kind of innervation is involved with V3? Via what?

Postganglionic parasympathetic innervation to sublingual and submandibular glands via lingual nerve

54

Any muscle associated with the mandibular arch must receive innervation from where?

V3 (mandibular)

55

The auriculotemporal branch contains what kind of fibers? It takes them where? Via what?

It contains postganglionic parasympathetic secretomotor fibers that go to the parotid gland via the parotid branches
(preganglionic fibers from CN 9)