Embryology of the Head & Neck Flashcards Preview

Unit 3: Embryology JC > Embryology of the Head & Neck > Flashcards

Flashcards in Embryology of the Head & Neck Deck (85)
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1
Q

Stomodeum gives rise to the ____.

A

mouth

2
Q

Frontal nasal prominence gives rise to the ____.

A

nose

3
Q

How many pairs of pharyngeal arches form?

A

5

4
Q

1st pharyngeal arch has 2 sub units: ____ and ____.

A

maxillary and mandibular prominences

5
Q

Formation of pharyngeal arches is driven by proliferation and migration of ____.

A

neural crest cells

6
Q

Pharyngeal arches are covered by ____. lined by ____, with a core made up of ____.

A

ectoderm, endoderm, mesenchyme

7
Q

1st pharyngeal arch is innervated by ____.

A

CN V - Trigeminal

8
Q

2nd pharyngeal arch is innervated by ____.

A

CN VII - Facial

9
Q

3rd pharyngeal arch is innervated by ____.

A

CN IX - Glossopharyngeal

10
Q

4th & 6th pharyngeal arches are innervated by ____.

A

CN X - Vagus

11
Q

The 1st pharyngeal arch differs from the others, in that it is lined predominantly by ____.

A

ectoderm

12
Q

Pharyngeal ____ separate the arches from the outside.

A

grooves

13
Q

Pharyngeal ____ separate the arches from the inside.

A

pouches

14
Q

The ____ is where the ectoderm and endoderm come together at the grooves/pouches.

A

pharyngeal membrane

15
Q

neural crest derivatives of arch 1 - maxillary prominence

A

facial bones (maxillary, zygomatic, squamous portion of temporal)

16
Q

neural crest derivatives of arch 1 - mandibular prominence

A

Meckel’s Cartilage - mandible, inner ear bones (incus & malleus), anterior ligament of malleus

17
Q

neural crest derivatives of arch 2

A

Reichart Cartilage - lesser cornu of hyoid (superior), stylohyoid ligament, styloid process, stapes

18
Q

neural crest derivatives of arch 3

A

body & greater cornu of hyoid (inferior)

19
Q

neural crest derivatives of arch 4/6

A

thyroid & cricoid cartilage

20
Q

mesoderm derivatives of arch 1

A

muscles of mastication (temporalis, masseter, mylohyoid, ant. digastric, tensor tympani)

21
Q

mesoderm derivatives of arch 2

A

muscles of facial expression (buccinator, orbicularis oris, frontalis, etc), stylohyoid, & post. digastric

22
Q

mesoderm derivatives of arch 3

A

stylopharyngeus

23
Q

mesoderm derivatives of arch 4/6

A

pharyngeal constrictors, m. of soft palate, & m. of larynx

24
Q

sensory innervation of arch 1

A

CN V - somatosensation of face, teeth, palate, and ant. 2/3 of tongue

25
Q

sensory innervation of arch 2

A

CN VII - taste to ant. 2/3 of tongue

26
Q

sensory innervation of arch 3

A

CN IX - taste and somatosensory to post. 1/3 of tongue

27
Q

sensory innervation of arch 4/6

A

CN X - taste and somatosensory to pharynx, larynx & esophagus

28
Q

endoderm derivative of pharyngeal pouch 1

A

middle ear cavity & auditory tube

29
Q

endoderm derivative of pharyngeal pouch 2

A

palatine tonsils

30
Q

endoderm derivative of pharyngeal pouch 3

A

inferior parathyroid glands & thymus

31
Q

endoderm derivative of pharyngeal pouch 4/6

A

superior parathyroid glands & ultimopharyngeal bodies

32
Q

derivative of pharyngeal groove 1

A

external auditory meatus

33
Q

derivative of pharyngeal grooves 2-4

A

cervical vesicle, which eventually degrades

34
Q

Cervical cyst/fistula/sinus occurs due to incomplete degradation of the ____.

A

cervical vesicle

35
Q

The ____ forms as a diverticulum in the endoderm between pharyngeal arch 1 & 2.

A

thyroid primordium

36
Q

The ____ connects the thyroid primordium with the ____ and eventually opens into the tongue via the ____.

A

thyroglossal duct, pharynx, foramen cecum

37
Q

The thyroglossal duct typically ____, but in rare cases remains and forms the ____ of the thyroid.

A

degrades, pyramidal lobe

38
Q

A ____ occurs when the thyroglossal duct improperly or incompletely degrades. Sometimes it contains ectopic thyroid tissue.

A

thyroglossal duct cyst

39
Q

The development of the tongue involves pharyngeal arches ____ to ____.

A

1 to 4

40
Q

The ____ develops in the first pharyngeal arch as the beginning of the development of the tongue.

A

median lingual swelling

41
Q

The median lingual swelling plays an inductive role in the formation of the ____.

A

lateral lingual swelling

42
Q

The lateral lingual swelling gives rise to the ____.

A

anterior 2/3 of the tongue

43
Q

In tongue formation, the 2nd pharyngeal arch gives rise to the ____ which eventually degrades, but plays an inductive role in the formation of the ____ from arches 3 & 4.

A

copula, hypopharyngeal eminence

44
Q

In tongue formation, the 2nd pharyngeal arch also gives rise to the ____.

A

taste buds

45
Q

The hypopharyngeal eminence from pharyngeal arches 3 & 4 gives rise to the ____.

A

posterior 1/3 of the tongue

46
Q

The median sulcus of the tongue is a remnant of ____.

A

the fusion of the lingual swellings

47
Q

The terminal sulcus of the tongue is a remnant of ____.

A

the fusion between pharyngeal arch 1 and the hypopharyngeal eminence

48
Q

The skeletal muscles of the tongue develop from ____, around week 5 of development.

A

occipital somites

49
Q

The anterior 2/3 of the tongue gets somatosensory innervation from ____ and special sensory (taste) innervation from ____.

A

CN V(3), CN VII

50
Q

The posterior 1/3 of the tongue gets somatosensory innervation from ____ and ____ and special sensory (taste) innervation from ____.

A

CN IX and X, CN IX

51
Q

The muscles of the tongue get motor innervation from ____.

A

CN XII

52
Q

What are the 4 types of papillae on the tongue?

A

filiform, fungiform, folliate, and circumvallate

53
Q

Which papillae of the tongue contain taste buds?

A

fungiform, folliate, and circumvallate

54
Q

Taste buds relay special sensory (taste) information via ____ and ____.

A

CN VII and IX

55
Q

Formation of the face begins as how many facial primordia around the stomodeum?

A

5

56
Q

What are the 5 facial primordia?

A

Frontonasal Prominence (FNP), Paired Maxillary Prominences (MxP), and Paired Mandibular Prominences (MdP)

57
Q

An ectodermal thickening, called the ____, forms on the FNP.

A

nasal placodes

58
Q

The mesenchyme below the nasal placodes proliferates and elevates up around the nasal placodes to form the ____.

A

nasal prominences

59
Q

The nasal placode invaginates into the underlying mesenchyme to form the ____ and dilates to become the ____.

A

nasal pit, nasal sac

60
Q

Growth and enlargement of the ____ push the nasal prominences to the midline, forcing them to fuse.

A

maxillary prominences

61
Q

Midline fusion of the nasal prominences gives rise to the ____ and ____.

A

bridge of the nose, intermaxillary segment

62
Q

The intermaxillary segment gives rise to the ____, ____, and ____.

A

philtrum (of upper lip), upper jaw w/ 4 incisors, primary palate

63
Q

The intermaxillary segment fuses with the ____ to allow fusion of the ____ and ____.

A

maxillary prominences, upper lip, palate

64
Q

____ also fuse with the maxillary prominence, and incomplete fusion results in ____.

A

lateral nasal prominences, oblique cleft

65
Q

____ forms at the site of fusion between the MxP and lateral nasal prominences, due to thickening and invagination of the ectoderm.

A

nasolacrimal duct

66
Q

The two ____ fuse at the midline to form a single nasal cavity.

A

nasal pits

67
Q

During development, the oral and nasal cavities are continuous due to the rupture of the ____.

A

oronasal membrane

68
Q

Formation of the ____ ultimately separates the oral and nasal cavities.

A

secondary palate

69
Q

____ develop from the lateral walls of the nasal cavity.

A

nasal conchae

70
Q

Cranial ectoderm in the nasal cavity differentiates to become the specialized ____.

A

olfactory epithelium

71
Q

The primary palate is derived from the ____.

A

intermaxillary segment

72
Q

The secondary palate is derived from the fusion of the ____.

A

palatine shelves

73
Q

The palatine shelves grow from the ____.

A

maxillary prominence

74
Q

At about week 9, the growing mandible allows the tongue to drop down, leaving room for the ____ to fuse at the midline, and to fuse anteriorly with the ____.

A

palatine shelves, primary palate

75
Q

Improper fusion of palatine shelves or of primary and secondary palate can result in ____.

A

cleft palate

76
Q

____ is an autosomal dominant gene mutation in a protein involved in preribosomal processing. Symptoms include cleft palate, micronathia, conductive deafness, and deformed facial features. Results from neural crest defects in pharyngeal arches ___ and ___.

A

Treacher Collins Syndrome, 1 and 2

77
Q

____ is characterized by micronathia, cleft palate, and susceptibility to respiratory distress syndrome at birth. It presents with heterogeneous birth defects with a range of severity.

A

Pierre Robin Syndrome

78
Q

____ is caused by a ~30 gene deletion on chromosome 22. It presents with a wide range of complications and severity, and is due to neural crest defects in pharyngeal arches & pouches ___, ___, ___, and ___.

A

DiGeorge Syndrome, 1, 2, 3, 4

79
Q

____ is the ectodermal origin of the teeth that develops in the mandible and maxilla.

A

dental lamina

80
Q

Dental lamina invaginates to form ____, which invaginate into themselves to form a cap around the condensing ____.

A

dental buds, dental papilla

81
Q

The dental papilla is mesenchyme derived from ____.

A

neural crest cells

82
Q

Each jaw (upper and lower) develops how many dental buds?

A

10

83
Q

The dental papilla (mesenchyme) differentiate into ____, which give rise to ____.

A

odontoblasts, dentin

84
Q

The outer epithelial/ectodermal dental cells differentiate into ____, which give rise to ____.

A

amelobasts, enamel

85
Q

Both ____ and ____ teeth are generated during fetal development, but their developmental stages are staggered.

A

deciduous, adult