Embryology

Question 1

How much of the embryo at week 4 will be the future head and neck?

Answer 1

1/2

Question 2

What is a pharyngeal arch?

Answer 2

Mesenchymal proliferations in the neck region of the embryo

Question 3

How many pharyngeal arches are there?

Answer 3

5 (1-4 and 6)

Question 4

What is the structure that will later form the nose called?

Answer 4

Frontonasal prominence

Question 5

Which cranial nerves are associated with the pharyngeal arches?

Answer 5

5,7,9,10

Question 6

Which muscles are derived from the 1st pharyngeal arch?

Answer 6

Muscles of Mastication

Question 7

Which muscles are derived from the 2nd pharyngeal arch?

Answer 7

Muscles of Facial expression

Question 8

What does the cartilage bar from the 1st pharyngeal arch form?

Answer 8

Malleus, incus and template for the mandible. Meckel’s.

Question 9

What does the cartilage bar from the 2nd pharyngeal arch form?

Answer 9

Stapes and upper part of hyoid bone. Reichert’s.

Question 10

What does the cartilage bar from the 3rd pharyngeal arch form?

Answer 10

The remainder of the hyoid bone

Question 11

What do the cartilage bars from the 4th and 6th pharyngeal arches form?

Answer 11

Cartilage of the larynx

Question 12

What happens to the 1st and 2nd arch arteries in forming the aorta and its branches?

Answer 12

They disappear

Question 13

Which arch artery forms the arch of the aorta?

Answer 13

4th arch artery

Question 14

Pharyngeal pouch vs cleft?

Answer 14

Pouch is the dip in endoderm, the cleft is on the outside in ectoderm

Question 15

What does the 1st pharyngeal pouch become?

Answer 15

Tympanic cavity

Question 16

What happens to the pharygeal clefts?

Answer 16

Only the 1st one remains becoming the external acoustic meatus, the 2nd arch grows downwards covering the other clefts

Question 17

Name 2 pathologies that can occur if there are remnants of the pharangeal clefts?

Answer 17

Branchial cyst/fistula

Question 18

What drives the development of the face?

Answer 18

Expansion of the cranial neural tube

Question 19

What is the stomatodeum?

Answer 19

A depression in the middle of the face that will later become the mouth, covered by buccopharyngeal membrane

Question 20

What are the nasal placodes?

Answer 20

Form on the frontonasal prominence, and sink to become nasal pits

Question 21

How is the secondary palate formed?

Answer 21

Maxillary prominence gives rise to 2 palatal shelve that grow together and downwards on each side of the developing tongue

Question 22

How is the primary palate formed?

Answer 22

Fusion of the medial nasal prominences create the intermaxillary segment. Contains the philtrum, 4 insisors and primary palate

Question 23

Which cleft does the external auditory meatus come from?

Answer 23

1st

Question 24

What is the path of the external ear to the standard anatomical position?

Answer 24

Develop initially on the neck, as the mandible grows the ear ascends to the sides of the head.

Question 25

Name 3 facial features common with fetal alcohol syndrome

Answer 25

Small head, low nasal bridge, small eye openings, short nose, underdeveloped jaw, smooth philtrum, thin upper lip