Head & Neck embryology

Question 1

what is the neck formed from?

Answer 1

pharyngeal/branchial arches

Question 2

what are the brnachiall arches?

Answer 2

series of arches which develop around the future mouth and pharynx

Question 3

how many branchial arches develop in humans?

Answer 3

5 develop ( 6 start to form but arch no.5 dissappears)

Question 4

what embryological tissues make up the branchial arches?

Answer 4

ectoderm - outside
mesoderm - middle (+neural crest cells)
endoderm - inside

Question 5

what do endoderm pouches form?

Answer 5

tongue

pituitary gland

Question 6

what is the relationship between branchial arches and nerves?

Answer 6

each branchial arch corresponds to a specific cranial nerve?

Question 7

what nerve is associated with the 1st arch?

Answer 7

mandibular branch of trigeminal nerve

Question 8

what nerve is associated with the 2nd arch?

Answer 8

facial nerve

Question 9

what nerve is associated with the 3rd arch?

Answer 9

glossopharyngeal nerve

Question 10

what nerve is associated with the 4th arch?

Answer 10

superior laryngeal branch of vagus

Question 11

what nerve is associated with the 6th arch?

Answer 11

recurrent laryngeal branch of vagus

Question 12

where do the muscles of the face form from?

Answer 12

2nd branchial arch

Question 13

which branchial arch does the digastric muscle form from?

Answer 13

1st

Question 14

what can be deduced from a muscles nerve supply?

Answer 14

which branchial arch it is derived from

Question 15

what is the upper part of the hyoid bone formed from?

Answer 15

the 2nd branchial arch

Question 16

what important structures develop from the branchial arches (excluding nerves)

Answer 16

tongue
thyroid gland
parathyroid gland
part of the pituitary gland

Question 17

what are the 5 processes/prominences that form the face?

Answer 17

frontonasal process
maxillary processes x 2
mandibular processes x 2

Question 18

what are the maxillary and mandibular processes formed from?

Answer 18

1st branchial arch mesoderm

Question 19

what is the nasal placode?

Answer 19

thickening of the ectoderm of the frontonasal process

Question 20

what is the philtrum?

Answer 20

a downward and lateral growth of the medial nasal process

Question 21

wht is the first stage of palate development?

Answer 21

medial nasal process grows downwards and forms philtrum, this forms the primary palate

Question 22

what is the second stage of of palate development?

Answer 22

two palatine shelves grow inwards from the maxillary processes

Question 23

what is the third stage of palate development?

Answer 23

palatine shelves meet in the midline to form the secondary palate

Question 24

what is the purpose of the palate?

Answer 24

to separate the oral and nasal cavities

Question 25

how is the cranial vault formed

Answer 25

membranous ossification

Question 26

what kind of bones are the cranial vault

Answer 26

flat bones

Question 27

what kind of bones form the base of the skull

Answer 27

irregular bones

Question 28

what is the viscerocranium?

Answer 28

skeleton of face

Question 29

how is the base of the skull formed

Answer 29

endochondral ossification

Question 30

what is craniosynostosis?

Answer 30

premature fusion of skull bones

Question 31

what is the mesenchyme around the notochord primarily formed from?

Answer 31

neural crest cells

Question 32

what is mesenchyme?

Answer 32

embryonic connective tissue

Question 33

what are somites derived from?

Answer 33

paraxial mesoderm

Question 34

what do somites form?

Answer 34

axial skeleton and muscles