Development Of Head And Neck

Front 1

what 4 types of "derm" compose the mesenchyme of the head region?

Back 1

paraxial mesoderm, lateral plate mesoderm, neural crest ectomesenchyme and ectodermal placodes (thickenings of ectoderm)

Front 2

what does the paraxial mesoderm segment into?

Back 2

somitomeres and somites

Front 3

what part of the cranium is formed by the paraxial mesoderm?

Back 3

cranial base and posterior part of the cranial vault

Front 4

what type of connective tissues is formed by the paraxial mesoderm in the craniofacial region?

Back 4

skeletal muscle, dermis, and other connective tissues

Front 5

what type of mesoderm forms the caudal meninges?

Back 5

paraxial

Front 6

what does the lateral plate mesoderm form?

Back 6

laryngeal cartilages and other connective tissues of this region

Front 7

where do the neural crest cells migrate into? why does it migrate there?

Back 7

pharyngeal (branchial) arches to surround cores of mesoderm

Front 8

what forms the pharyngeal arch and facial skeletal connective tissues?

Back 8

neural crest cells

Front 9

what does the neural crest cells join with to form sensory ganglia of certain cranial nerves? which cranial nerves are they?

Back 9

join with cells of thickened regions of overlying ectoderm (ectodermal placodes) to form the sensory ganglia of CN V, VII, IX, and X

Front 10

when do the pharyngeal arches develop? where do they appear?

Back 10

fourth and fifth weeks of development. They appear in the future face and anterior neck of the embryo.

Front 11

how many pairs of pharyngeal arches develop? which pair is rudimentary/ absent in humans?

Back 11

six pairs; the fifth pair

Front 12

what externally separates the mesenchyme that create the pharyngeal arches? internally?

Back 12

pharyngeal clefts; pharyngeal pouches

Front 13

each pharyngeal arch has four components, what are they?

Back 13

skeletal, muscular, nervous, and arterial

Front 14

during migration, which component of the pharyngeal arch carries its innervation with it?

Back 14

muscular

Front 15

which component of the pharyngeal arch is made of cartilage?

Back 15

skeletal

Front 16

what will the first pharyngeal arch eventually develop into?

Back 16

upper and lower jaw

Front 17

what are the names of the 2 processes that the first pharyngeal are consists of? what will they eventually form?

Back 17

maxillary process - upper jaw; mandibular process - lower jaw

Front 18

what does the first pharyngeal arch join to form the face around the primitive oral cavity? what is the other name for an oral cavity?

Back 18

frontonasal prominence; stomodeum

Front 19

which pharyngeal arch is also called meckel's cartilage?

Back 19

first pharyngeal arch

Front 20

T/F
The mandible forms intramembranously around Meckel's cartilage

Back 20

TRUE!

Front 21

how many pairs of pharyngeal arches develop? which pair is rudimentary/ absent in humans?

Back 21

six pairs; the fifth pair

Front 22

what externally separates the mesenchyme that create the pharyngeal arches? internally?

Back 22

pharyngeal clefts; pharyngeal pouches

Front 23

each pharyngeal arch has four components, what are they?

Back 23

skeletal, muscular, nervous, and arterial

Front 24

during migration, which component of the pharyngeal arch carries its innervation with it?

Back 24

muscular

Front 25

which component of the pharyngeal arch is made of cartilage?

Back 25

skeletal

Front 26

what will the first pharyngeal arch eventually develop into?

Back 26

upper and lower jaw

Front 27

what are the names of the 2 processes that the first pharyngeal are consists of? what will they eventually form?

Back 27

maxillary process - upper jaw; mandibular process - lower jaw

Front 28

what does the first pharyngeal arch join to form the face around the primitive oral cavity? what is the other name for an oral cavity?

Back 28

frontonasal prominence; stomodeum

Front 29

What is the first pharyngeal arch cartilage called?

Back 29

Meckel's cartilage

Front 30

T/F
The mandible forms intramembranously around Meckel's cartilage

Back 30

TRUE!

Front 31

what does Meckel's cartilage form?

Back 31

malleus, incus, anterior ligament of the malleus of the middle ear and the sphenomandibular ligament

Front 32

what are the other parts of the skull that develop from the first pharyngeal arch through intramembranous ossification?

Back 32

Maxilla, premaxilla, zygomatic bone, and squamous part of the temporal bone

Front 33

what muscles does the first pharyngeal arch give rise to?

Back 33

(8) muscles: (muscles of mastication): masseter, temporalis, lateral pterygoid, and medial pterygoid; the mylohyoid and anterior belly of the digastric; tensor tympani (middle ear), and tensor veli palatini (soft palate)

Front 34

what is the nerve of the first pharyngeal arch?

Back 34

trigeminal nerve (CN V)

Front 35

through what division of the trigeminal nerve are the muscles of the first pharyngeal arch being innervated by?

Back 35

mandibular division (V3)

Front 36

how is sensory innervation supplied to the face via the first pharyngeal arch?

Back 36

through the three divisions of the trigeminal nerve

Front 37

what is the name of the cartilage that is found in the second pharyngeal arch?

Back 37

reichert's

Front 38

what does reichert's cartilage give rise to?

Back 38

stapes, styloid process of the temporal bone, stylohyoid ligament, the lesser horn and upper part of the body of the hyoid bone

Front 39

what muscles does the second pharyngeal arch give rise to?

Back 39

muscles of facial expression + buccinator muscle; stylohyoid and posterior belly of the digastric, and stapedius

Front 40

what is the nerve of the second pharyngeal arch?

Back 40

facial nerve (CN VII)

Front 41

which branch of the facial nerve is sent to the first branch? why?

Back 41

chorda tympani because it carries taste from the anterior 2/3 of the tongue

Front 42

what type of connective tissue forms the lower part of the body and greater horn of the hyoid bone?

Back 42

cartilage

Front 43

what does the third pharyngeal arch give rise to?

Back 43

stylopharyngeus muscle

Front 44

what innervates the third pharyngeal arch?

Back 44

glossopharyngeal CN IX

Front 45

what fuses between the fourth and sixth pharyngeal arches? what does it form?

Back 45

cartilaginous components to form cartilages of the larynx (thyroid, cricoid, artenoid, corniculate, and cuneiform)

Front 46

what muscles does the fourth pharyngeal arch give rise to? (innervated by pharyngeal branch)

Back 46

muscles of the soft palate (except tensor veli palatini) and pharynx (except stylopharyngeus);

Front 47

what muscles does the fourth pharyngeal arch give rise to? (innervated by external laryngeal branch)

Back 47

cricothyroid muscle of the larynx

Front 48

what innervates the fourth pharyngeal arch? (name general CN)

Back 48

vagus

Front 49

what muscles does the sixth pharyngeal arch give rise to?

Back 49

intrinsic muscles of the larynx (except cricothyroid)

Front 50

what innervates the sixth pharyngeal arch?

Back 50

recurrent laryngeal branch of the vagus nerve

Front 51

what are pharyngeal pouches?

Back 51

outpocketings of the pharyngeal wall, separating the pharyngeal arches internally

Front 52

what is the first pharyngeal pouch also known as?

Back 52

tubotympanic recess

Front 53

what does the tubotympanic recess come into contact with? (forming the external auditory meatus)

Back 53

first pharyngeal cleft

Front 54

what does the first pharyngeal pouch form? what does it contribute to?

Back 54

the primitive tympanic (middle ear) cavity and auditory/eustachian tube; tympanic membrane (eardrum)

Front 55

what does the second pharyngeal pouch help form? how does it partially persist in adulthood?

Back 55

palatine tonsil; tonsillar fossa

Front 56

what does the dorsal portion of the third pharyngeal pouch form? the ventral portion?

Back 56

inferior parathyroid gland; thymus

Front 57

what does the dorsal portion of the fourth pharyngeal pouch form? ventral portion?

Back 57

superior parathyroid gland; ultimobranchial body

Front 58

what does the ultimobranchial body give rise to? what do they secrete?

Back 58

parafollicular cells; calcitonin

Front 59

since the _____ and parathyroid _____ migrate during development, what may persist along the pathway?

Back 59

thymus, glands; accessory glands or remnants of tissues

Front 60

which gland is particularly variable in position?

Back 60

inferior parathyroid gland

Front 61

what forms the external auditory meatus? At what week of development?

Back 61

first pharyngeal cleft; week 5

Front 62

which cleft contributes its epithelial lining to the tympanic membrane?

Back 62

first

Front 63

what temporarily forms the cervical sinus?

Back 63

pharyngeal clefts 2-4

Front 64

what is a lateral cervical cyst?

Back 64

remnant of the cervical sinus located laterally along the anterior border of the sternocleidomastoid muscle

Front 65

in association with the lateral cervical cyst, what might you see that will be connecting the cyst with a surface?

Back 65

external or internal fistula

Front 66

when does the face develop?

Back 66

beginning in the fourth week of development

Front 67

what are the five facial primordia that develop the face?

Back 67

the frontonasal prominence, two maxiallry prominences, and 2 mandibular prominences

Front 68

the medial and lateral nasal prominences develop of the sides of what?

Back 68

nasal placode (ectodermal thickening)

Front 69

what forms the nasal pit?

Back 69

invagination of the nasal placode

Front 70

what do the two medial nasal prominences merge to form?

Back 70

the intermaxillary segment

Front 71

what does the intermaxillary segment form?

Back 71

philtrum of the upper lip, portion of the maxillary alveolar process carrying the four incisor teeth, and primary palate

Front 72

what comprises the premaxilla?

Back 72

primary palate and maxillary alveolar process carrying the incisor teeth together

Front 73

what does the medial nasal prominence fuse with to form the upper lip?

Back 73

maxillary prominences

Front 74

what initially separates the lateral nasal and maxillary prominences?

Back 74

nasolacrimal groove

Front 75

what eventually forms in the nasolacrimal groove? what is the function?

Back 75

nasolacrimal duct which will later connect the lacrimal sac in the orbit and the inferior meatus of the nasal cavity.

Front 76

what forms the dorsum of the nose? sides? crest and tip?

Back 76

frontonasal prominence; lateral nasal prominence; merged medial nasal prominences

Front 77

what initially separates the nasal cavity from the oral cavity?

Back 77

oronasal membrane

Front 78

what completes the division of the nasal and oral cavities?

Back 78

formation of the secondary palate

Front 79

where does the oronasal membrane break down?

Back 79

future site of the incisive canals to form the primitive choanoae

Front 80

what prominences merge to form the lower lip?

Back 80

mandibular

Front 81

what forms the secondary palate?

Back 81

lateral palate shelves (outgrowths from the maxillary prominences)

Front 82

above which muscle does the palate shelves reorient to a horizontal position?

Back 82

tongue

Front 83

with what do the palatal shelves fuse with above? anteriorly?

Back 83

nasal septum; primary palate

Front 84

what is the midline landmark on the prepared skull between the primary and secondary palates?

Back 84

incisive canals

Front 85

what do abnormally small facial processes result from? what may be the cause?

Back 85

deficient neural crest migration and proliferation; high doses of retinoic acid ( Vit A)

Front 86

what is cleft lip the result of? frequency?

Back 86

failure of the maxillary and medial nasal prominences to fuse; 1/1000

Front 87

which version of cleft lip is more prominent, one involving the primary palate or the secondary palate?

Back 87

primary

Front 88

the anterior 2/3 of the tongue is formed from which pharyngeal arch? how?

Back 88

1st; when the lateral lingual swellings overgrow the tuberculum impar

Front 89

from which pharyngeal arch does the posterior 1/3 of the tongue develop? how?

Back 89

3rd; when the 3rd pharyngeal arch overgrows that of the second arches in the copula (hypobranchial eminence)

Front 90

which pharyngeal arch forms the extreme posterior part? from what type of swelling?

Back 90

fourth; epiglottic

Front 91

what is the innervation for the posterior 1/3 of the tongue?

Back 91

GSA and GVA, glossopharyngeal nerve

Front 92

what type of fibers does the extreme posterior part receive innervation from? what CN innervates it?

Back 92

GVA and some SVA; vagus (specifically: superior laryngeal branch)

Front 93

where do the tongue muscles develop from? carrying which nerve?

Back 93

myoblasts that migrate from occipital somites; hypoglossal nerve

Front 94

what is ankyloglossia?

Back 94

insufficient tissue degeneration resulting in a lingual frenulum that is short and extends to the tip of the tongue, interfering with tongue protrusion and feeding.

Front 95

how does the thyroid gland begin development as?

Back 95

endodermal proliferation

Front 96

where is the thyroid gland's final destination?

Back 96

in front of the trachae

Front 97

how is the thyoid primordium connected to the foramen cecum of the tongue? what can form there or anywhere along the path of migration?

Back 97

thyroglossal duct; thyroglossal cysts or aberrant thyroid tissue

Front 98

T/F
the only way to tell (externally) between a branchial cyst and a thyroglossal cyst is their distance from the midline.

Back 98

TRUE!

Front 99

where does the pyramidal lobe frequently extend from?

Back 99

isthmus of the thyroid along the gland's path of migration

Front 100

what connects the pyramidal lobe to the hyoid bone?

Back 100

connective tissue and/or a levator glandulae thyroideae.