Development Of The Head And Neck

Question 1

Where and when do the pharyngeal arches form?

Answer 1

In the lateral walls of the embryonic pharynx in the 4th week of development

Question 2

What nerves is each arch 1 2 3 4 6 associated with?

Answer 2

5 7 9 10

Trigeminal - 1

Facial - 2

Glossopharyngeal - 3

Vagus - 4/6

Question 3

What arteries are the pharyngeal arches associated with?

Answer 3

Common external and internal
1-2-3

Aortic arch (left) and right subclavian 
4

Pulmonary arteries
6

Question 4

Name the muscles that derive from the first pharyngeal arch.

Answer 4

Muscles of mastication 
Tensor tympani 
Tensor veli palitini 
Mylohyoid
Anterior belly of digastric

Question 5

What muscles arise from the 4-6th pharyngeal arch?

Answer 5

Constrictor muscles of the pharynx
Laryngeal muscles
Striated muscles of the oeso[phagus
Muscles of the soft palate (levator veli palatini)

Question 6

What cartilaginous structure arises from the 3/4th arch?

Answer 6

Epiglottis

Question 7

Where do the 3 different ear bones originate?

Answer 7

Malleus and incus - 1st arch

Stapes from the second arch

Question 8

Where does the stylohyoid ligament originate?

Answer 8

The second arch

Question 9

What arch does the Meckel’s cartilage derive from and what does it become?

Answer 9

Future mandible, malleus and incus

Arch 1

Question 10

What will the reicherts cartilage become?

Answer 10

Superior part of hyoid
Stapes
Styloid process
Stylohydoid ligament

Question 11

What does 2nd pharyngeal pouch become?

Answer 11

Palatine tonsil

Question 12

What does the first pharyngeal cleft become?

Answer 12

External acoustic meatus

Question 13

What is the difference between an internal and external cervical fistula?

Answer 13

External communicates with the skin

Internal communicates with the pharynx

Question 14

What 2 structures make up the primordia of the face?

Answer 14

1st pharyngeal arch

Frontonasal prominence

Question 15

What will the FNP develop into?

Answer 15

Forehead
bridge of nose
Philtrum
Nose

Question 16

Fusion of what forms the intermaxillary segment?

What is the intermaxillary segment made of?

Answer 16

Medial nasal prominences

Philtrum, upper jaw (4 incisors) and the primary palate

Question 17

Describe the development of the secondary palate.

Answer 17

Palatal shelves will originate from the maxillary prominences. These will grow downwards and fuse in the mid line.

The mandible will grow to allow for the tongue to drop down.

Question 18

How does a cleft lip form?

Answer 18

Failure of fusion of the medial nasal prominence with he maxillary prominence

Question 19

How does a cleft palate form?

2 possible issues with this?

Answer 19

Failure of the palatal shelves to fuse in the midline.

Feeding and speech difficulties

Question 20

From where does the auricle develop?

How does it end up in line with the eyes?

Answer 20

Proliferation of the 1st and 2nd arches around the meatus.

Starts in the neck region but then as the mandible grows it ascends to the side of the head to lie in line with eyes

Question 21

Give some signs of FAS.

Answer 21

Underdeveloped jaw 
Thin upper lip 
Smooth philtrum 
Short nose
Epicanthal folds
Low nasal bridge 
Small head 
Flat midface

Question 22

What does the lateral nasal prominence become?

Answer 22

Sides of the node