Sievert: Cranial Primordia, skull, face, and scalp

Question 1

Ectodermal thickenings that form structures for some of our special senses

Answer 1

placodes

Question 2

List three important placodes

Answer 2

olfactory placode
lens placode
otic placode

Question 3

The nasal placode is induced by the adjacent (blank) of the forebrain

Answer 3

olfactory bulb

Question 4

The nasal placode forms the primary (blank) - the cells of smell grow into the olfactory bulb through the (blank) bone

Answer 4

olfactory epithelium; ethmoid bone

Question 5

An outpocketing of the forebrain induces a thickening of the surface ectoderm which will form the (blank) placode or vesicle

Answer 5

lens placode

Question 6

The otic placode forms what two things? So basically, what does the otic placode form up?

Answer 6

membranous labyrinth and sensory neurons of cranial nerve VIII; the inner ear!

Question 7

The inner ear develops fairly slowly. Why is this important to consider?

Answer 7

may be susceptible to environmental defects

Question 8

What does the middle ear cavity form from?

Answer 8

the adjacent 1st pharyngeal pouch lined by endoderm

Question 9

Masses of mesorderm that form skeletal muscles

Answer 9

somites

Question 10

(blank) somites form muscles that move the eye, but not muscles of the iris or the lens. (blank) somites form muscles of the tongue.

Answer 10

preotic; postotic

Question 11

Masses of mesenchyme tissue that flank the developing gut

Answer 11

pharyngeal arches

Question 12

When do pharyngeal arches appear around the developing gut?

Answer 12

4th-5th week

Question 13

Each pharyngeal arch consists of a core of mesenchyme surrounded by (blank) on the outside and (blank) on the inside.

Answer 13

ectoderm; endoderm

Question 14

What exists in the core of pharyngeal arches to contribute to skeletal components of the face?

Answer 14

neural crest cells

Question 15

List the pharyngeal arch derivatives

Answer 15

muscle
bone or cartilage
skin from the overlying ectoderm
lining of the gut from the lining endoderm

Question 16

Each pharyngeal arch forms (blank) or (blank)

Answer 16

cartilage; bone

Question 17

The maxillary process forms what three things?

Answer 17

maxilla
zygomatic bone
part of the temporal bone

Question 18

The madibular process forms what three things?

Answer 18

mandible
malleus
incus

Question 19

The second arch, or the hyoid arch, forms what things?

Answer 19

lesser horn of hyoid bone
styloid process
stapes

Question 20

What does the third arch form?

Answer 20

the rest of the hyoid bone

Question 21

What do the 4th and 6th arches fuse to form?

Answer 21

the laryngeal cartilages

Question 22

What muscles are derived from the first pharyngeal arch?

Answer 22

muscles of mastication

Question 23

What muscles are derived from the second pharyngeal arch?

Answer 23

muscles of facial expression

Question 24

What muscle is derived from the third pharyngeal arch?

Answer 24

stylopharyngeus

Question 25

What muscles are derived from the 4th and 6th pharyngeal arches?

Answer 25

muscles of the pharynx, larynx, and palate

Question 26

What innervates the endoderm lining each pharyngeal arch?

Answer 26

the nerve of that arch

Question 27

What does the first pharyngeal pouch form?

Answer 27

middle ear | auditory/eustachian tube

Question 28

What does the second pharyngeal pouch form?

Answer 28

palatine tonsil

Question 29

What does the third pharyngeal pouch form?

Answer 29

thymus | inferior parathyroid glands

Question 30

What does the fourth pharyngeal pouch form?

Answer 30

superior parathyroid glands

Question 31

What does the fifth pharyngeal pouch form?

Answer 31

C cells of the thyroid gland

Question 32

What are the three cranial nerves to placodes?

Answer 32

1, 2, 8

Question 33

What are the four cranial nerves to somites?

Answer 33

3, 4, 6, 12

Question 34

What are the four cranial nerves to branchial arches?

Answer 34

5, 7, 9, 10

Question 35

Which cranial nerve is associated with the olfactory placode?

Answer 35

cranial nerve 1 - olfactory

Question 36

Which cranial nerve is associated with the optic vesicle?

Answer 36

cranial nerve 2 - optic

Question 37

Which cranial nerves are associated with preotic somites (3)?

Answer 37

cranial nerve 3 - oculomotor cranial nerve 4 - trochlear cranial nerve 6 - abducens

Question 38

Which cranial nerve is associated with branchial arch 1?

Answer 38

cranial nerve 5 - trigeminal

Question 39

Which cranial nerve is associated with branchial arch 2?

Answer 39

cranial nerve 7 - facial

Question 40

Which cranial nerve is associated with the otic placode?

Answer 40

cranial nerve 8 - vestibulocochlear

Question 41

Which cranial nerve is associated with branchial arch 3?

Answer 41

cranial nerve 9 - glossopharyngeal

Question 42

Which cranial nerve is associated with branchial arch 4?

Answer 42

cranial nerve 10 - vagus

Question 43

Which cranial nerve is associated with branchial arch 6?

Answer 43

cranial nerve 10 - vagus

Question 44

Which cranial nerve is associated with postotic somites?

Answer 44

cranial nerve 12 - hypoglossal

Question 45

What four things may spinal nerves contain?

Answer 45

general sensory (GSA) viscerosensory (GVA) somatomotor (GSE) visceromotor (GVE)

Question 46

Potential cranial nerve components. Give an example of each: 1. Special somatosensory 2. General somatosensory 3. General viscerosensory 4. Special viscerosensory 5. visceromotor 6. somatomotor 7. branchiomotor

Answer 46

1. vision and balance/hearing 2. skin 3. gut 4. taste buds/nasal placode 5. autonomic 6. muscles from somites 7. muscles from branchial arches

Question 47

Cell bodies of nuclei are organized. All motor neurons of cranial nerves are in the (blank). All sensory neurons of cranial nerves 3-12 are in ganglia except which?

Answer 47

brainstem; except for the proprioceptive fibers for the face

Question 48

What is the order of columns within the alar plate (from lateral to medial)?

Answer 48

special somatosensory general somatosensory general and special viscerosensory

Question 49

What is the order of columns within the basal plate (from lateral to medial)?

Answer 49

somatomotor branchiomotor visceromotor

Question 50

Which cranial nerves have somatomotor components?

Answer 50

3, 4, 6, 12

Question 51

Which cranial nerves have visceromotor components?

Answer 51

3, 7, 9, 10

Question 52

Which cranial nerves have branchiomotor components?

Answer 52

5, 7, 9, 10

Question 53

Which cranial nerves have special sensory components?

Answer 53

1, 2, 7, 8, 9, 10

Question 54

Which cranial nerves have general sensory components?

Answer 54

5, 7, 9, 10

Question 55

Which cranial nerves have visceral sensory components?

Answer 55

9, 10

Question 56

Which cranial nerves include taste?

Answer 56

7, 9, 10

Question 57

Which cranial nerve has neurons that are not in the brainstem, but may have somato and branchio components?

Answer 57

cranial nerve 11

Question 58

What are the three components of the sensory innervation of the face and scalp?

Answer 58

trigeminal nerve dorsal rami of cervical spinal nerves (greater occipital nerve) branches from cervical plexus (ventral rami)

Question 59

What are the three divisions of the trigeminal nerve?

Answer 59

``` ophthalmic division (V1) maxillary division (V2) mandibular division (V3) ```

Question 60

What are the three foramina and what branches do they transmit?

Answer 60

1. supraorbital foramen for supraorbital nerve from V1 2. infraorbital foramen for infraorbital nerve from V2 3. mental foramen for mental nerve from V3

Question 61

What is a distinguishing feature of the medulla?

Answer 61

pyramids

Question 62

What are two distinguishing features of the pons?

Answer 62

1. pyramids are sunken into the pontine gray | 2. there is a mass of cells whose axons form the middle cerebellar peduncle

Question 63

In the midbrain, the corticospinal, corticobulbar, and corticopontine fibers are collected into a bundle known as the (blank), which gives the midbrain an easily recognizable look.

Answer 63

cerebral peduncle

Question 64

Where do cranial nerves 5, 6, 7, 8 exit the brainstem?

Answer 64

PONS

Question 65

Where do 9, 10, 11, 12 exit the brainstem?

Answer 65

medulla

Question 66

Where do 3 and 4 exit the brainstem?

Answer 66

midbrain

Question 67

Where do cranial nerves 1 and 2 emerge from?

Answer 67

cerebrum or forebrain

Question 68

In general, motor nuclei are present (blank), and sensory nuclei are present (blank).

Answer 68

ventrally; dorsally

Question 69

The muscles of facial expression are derived from which pharyngeal arch? Where do this muscles insert? What do they produce? What other function do they have?

Answer 69

2; insert into the skin; produce facial expressions; protective function

Question 70

What are the terminal branches of cranial nerve 7?

Answer 70

``` temporal zygomatic buccal mandibular cervical ``` **ten zebras bought my car

Question 71

The terminal branches of cranial nerve 7 pass through what structure?

Answer 71

parotid gland

Question 72

The terminal branches of the 7th cranial nerve exit via the (blank) foramen, and are mostly (blank)

Answer 72

stylomastoid foramen; motor

Question 73

The facial motor nucleus is in the (blank) column and sends its axons on a circuitous route over the (blank) nucleus to exit with the facial nerve from the caudal pons.

Answer 73

branchiomotor; abducens

Question 74

The motor fibers from the facial motor nucleus leave the nucleus and arch over the top of the (blank) nucleus before exiting on the facial nerve. The facial nerve has an interesting route through the skull. Why is this important?

Answer 74

abducens; the facial nerve can be damaged at many places and the symptoms vary depending on the place

Question 75

As the facial nerve leaves the stylomastoid foramen, what component is affected if it is damaged?

Answer 75

SVE

Question 76

What is this: the muscles of facial expression are paralyzed, so all of the muscles on that side of the face are involved.

Answer 76

Bell's palsy

Question 77

What are the superficial arterial branches of the head?

Answer 77

external carotid artery | internal carotid artery (**via ophthalmic artery)

Question 78

What are the external carotid artery branches?

Answer 78

superficial temporal | facial/angular

Question 79

What are the internal carotid artery branches?

Answer 79

supraorbital supratrochlear **numerous anastomoses between branches

Question 80

List the layers of the scalp from superficial to deep

Answer 80

``` skin CT aponeuroses loose CT pericranium ```

Question 81

The first 3 layers of the scalp are usually considered the (blank). Which layer has numerous arteries anastomosing? Why is this significant? Which layer is considered the danger space? Why?

Answer 81

scalp proper; CT layer; significance for bleeding; loose CT layer; can lead to spread of infection

Question 82

Skull Thin/pliable bones? Sutures? Fontanels?

Answer 82

frontal, parietal, occipital; sagittal, coronal, lambdoid; anterior, posterior

Question 83

Premature suture closure occurs in 1/2500 births found in >100 genetic syndromes

Answer 83

craniosynostosis

Question 84

Scaphocephaly involves which suture? | Brachycephaly or oxycephaly involves which sutures?

Answer 84

sagittal suture; coronal and lambdoid sutures