Embryology

Question 1

how many pharyngeal arches are there

Answer 1

5

Question 2

what are pharyngeal arches

Answer 2

projections of proliferating mesoderm coming from the neck region of the developing embryo

Question 3

what is associated with each pharyngeal arch

Answer 3

artery, cranial nerve and cartilage

Question 4

what nerve is associated with pharyngeal arch 1

Answer 4

trigeminal

Question 5

what nerve is associated with pharyngeal arch 2

Answer 5

facial

Question 6

what nerve is associated with pharyngeal arch 3

Answer 6

glossopharyngeal

Question 7

what nerve is associated with pharyngeal arch 4

Answer 7

vagus

Question 8

what nerve is associated with pharyngeal arch 6

Answer 8

hypoglossal

Question 9

what does the cartilage associated with pharyngeal arch 1 develop into

Answer 9

incus, malleus and template for the mandible

Question 10

what does the cartilage associated with pharyngeal arch 2 develop into

Answer 10

middle ear bones and part of the hyoid bone

Question 11

what does the cartilage associated with pharyngeal arch 3 develop into

Answer 11

part of the hyoid bone

Question 12

what does the cartilage associated with pharyngeal arch 4 develop into

Answer 12

larynx cartilage

Question 13

what does the cartilage associated with pharyngeal arch 6 develop into

Answer 13

larynx cartilage

Question 14

describe what happens to the aortic arches in development

Answer 14

the first 2 degree
3rd = internal carotid
4th = arch of aorta (L) and brachiocephalic (R)
6 = pulmonary arch

Question 15

what is the mesoderm derivative of pharyngeal arch 1

Answer 15

muscles of mastication

Question 16

what is the mesoderm derivative of pharyngeal arch 2

Answer 16

muscles of facial expression

Question 17

what is the mesoderm derivative of pharyngeal arch 3

Answer 17

stylopharyngeus muscle in the head

Question 18

what is the mesoderm derivative of pharyngeal arch 4

Answer 18

constrictors or pharynx, cricothyroid muscle and levator palatini

Question 19

what is the mesoderm derivative of pharyngeal arch 6

Answer 19

larynx muscles

Question 20

what is the name of the 1st pharyngeal pouch

Answer 20

tympanic cavity

Question 21

what do the pharyngeal pouches develop into

Answer 21

palatine tonsils, parathyroid glands, thymus

Question 22

what does the 1st pharyngeal cleft develop into

Answer 22

external auditory meatus

Question 23

what is the stomatodeum

Answer 23

the space between the frontonasal prominence and 1st pharyngeal arch that will become the oral cavity

Question 24

in the development of the face, what will derive from the FNP

Answer 24

forehead, bridge or nose, philtrum

Question 25

in the development of the face, what will derive from the the maxillary part of the 1st arch

Answer 25

cheek, upper lateral lip, lateral upper jaw

Question 26

in the development of the face, what will derive from the mandibular part of the 1st arch

Answer 26

lower lip and jaw

Question 27

what does the 1st pharyngeal pouch develop into

Answer 27

the small bones of the ears (ossicles) and the middle ear

Question 28

describe the development of the nose

Answer 28

the nasal placoderms sink in to become nasal pits - these are surrounded by medial and lateral nasal prominences the maximally prominence then grows medially pushing the 2 medial nasal prominences together which fuse to form the intermaxillary segment the maxillary prominences are known as the palatal shelves and these also fuse together to form the palate

Question 29

what is lateral cleft lip

Answer 29

where the medial nasal prominences fail to fuse

Question 30

what is cleft lip and cleft palate

Answer 30

where the medial nasal prominences and the palatal shelves fail to fuse

Question 31

what type of tissue does the infundibulum develop from

Answer 31

neurectoderm

Question 32

what does the infundibulum develop into

Answer 32

posterior pituitary gland

Question 33

what type of tissue does Rathke's pouch develop from

Answer 33

ectoderm

Question 34

what does Rathke's pouch develop into

Answer 34

anterior pituitary gland

Question 35

where does the thyroid gland start developing from

Answer 35

at the foramen caecum at the base of the tongue

Question 36

what duct does the thyroid gland move down

Answer 36

the thryoglossal duct

Question 37

what can form if the thyroglossal duct doesn't fully degenerate

Answer 37

thryoglossal cysts fistuales

Question 38

which pharyngeal arches contribute to the tongue

Answer 38

all 5 of the arches

Question 39

name the areas of the pharyngeal arches which make up the tongue

Answer 39

1 - lateral lingual swellings and Tuberculum impar 2 and 3 - cupola 4- epiglottal swelling

Question 40

describe the growth of the pharyngeal arches to give the tongue

Answer 40

the lateral lingual swellings and cupola overgrow the Tuberculum impar so that the 2nd arch no longer forms part of the tongue

Question 41

what is the only attachment of the tongue to the base of the oral cavity

Answer 41

lingual frenulum

Question 42

what nerve supplies the taste buds

Answer 42

chorda tympani branch of the facial nerve

Question 43

what migrates to the tongue to form the intrinsic and extrinsic tongue muscles and what nerve is associated with this

Answer 43

occipital somites which are associated with CN XII

Question 44

what is Treacher Collins syndrome

Answer 44

where neural crest cells fail to migrate to the 1st pharyngeal arch

Question 45

what are the consequences of Treacher Collins syndrome

Answer 45

hypoplasia of the mandible and facial bones

Question 46

what is Di-Georges syndrome

Answer 46

failure of the neural crest cells to develop in the 3rd and 4th pharyngeal arches

Question 47

what are the consequences of Di-Georges syndrome

Answer 47

immunodeficiency - due to hypoplasia of the thymus so little T cell maturation hypocalceamia - due to absence of parathyroid glands

Question 48

what is charge syndrome

Answer 48

where neural crest cells abnormally differentiate to become multipotent