embryology of head and neck

Question 1

what three groups is the mesoderm organised into

Answer 1

paraxial, intermediate and lateral plate

Question 2

when is pharyngeal arch 1 develop

Answer 2

day 22

Question 3

when do pahryngeal arches 2 and 3 develop

Answer 3

day 24

Question 4

when do pharyngeal arches 4 and 6 develop

Answer 4

day 29

Question 5

what are the three components of the pharyngeal apparatus

Answer 5

• core pharyngeal arch (mesenchymal tissue)
• external pharyngeal cleft (ectoderm)
• internal pharyngeal pouch (endoderm)

Question 6

what does each pharyngeal pouch consist of

Answer 6

• core mesenchyme derived from paraxial and lateral plate mesoderm
• neural crest cells
• cranial nerve component
• artery

Question 7

what is the first pharyngeal arch

Answer 7

• maxillary process (cranial)

- mandibular process (caudal)

Question 8

what are the skeletal derivates of the 2nd arch

Answer 8

• stapes
• styloid process of temporal bone
• stylohyoid ligament
• lesser horn of hyoid
• upper part of hyoid bone

Question 9

what are the skeletal derivatives of the 3rd arch

Answer 9

• greater horn

- lower part of hyoid bone

Question 10

skeletal derivatives of the 4th and 6th arches

Answer 10

laryngeal cartilages

Question 11

neural derivative of first arch

Answer 11

trigeminal nerve

Question 12

neural derivative of 2nd arch

Answer 12

facial nerve

Question 13

neural derivative of 3rd arch

Answer 13

glossopharyngeal nerve

Question 14

neural derivative of arch 4 and 6

Answer 14

vagus nerve

Question 15

muscular derivatives of first arch

Answer 15

• muscles of facial expression
• posterior belly of digastric
• stylohyoid
• strapedius
• auricular muscles

Question 16

muscular derivatives of second arch

Answer 16

exact same as first arch