Development Of The Head And Neck Flashcards
Where and when do the pharyngeal arches form?
In the lateral walls of the embryonic pharynx in the 4th week of development
What nerves is each arch 1 2 3 4 6 associated with?
5 7 9 10
Trigeminal - 1
Facial - 2
Glossopharyngeal - 3
Vagus - 4/6
What arteries are the pharyngeal arches associated with?
Common external and internal
1-2-3
Aortic arch (left) and right subclavian 4
Pulmonary arteries
6
Name the muscles that derive from the first pharyngeal arch.
Muscles of mastication Tensor tympani Tensor veli palitini Mylohyoid Anterior belly of digastric
What muscles arise from the 4-6th pharyngeal arch?
Constrictor muscles of the pharynx
Laryngeal muscles
Striated muscles of the oeso[phagus
Muscles of the soft palate (levator veli palatini)
What cartilaginous structure arises from the 3/4th arch?
Epiglottis
Where do the 3 different ear bones originate?
Malleus and incus - 1st arch
Stapes from the second arch
Where does the stylohyoid ligament originate?
The second arch
What arch does the Meckel’s cartilage derive from and what does it become?
Future mandible, malleus and incus
Arch 1
What will the reicherts cartilage become?
Superior part of hyoid
Stapes
Styloid process
Stylohydoid ligament
What does 2nd pharyngeal pouch become?
Palatine tonsil
What does the first pharyngeal cleft become?
External acoustic meatus
What is the difference between an internal and external cervical fistula?
External communicates with the skin
Internal communicates with the pharynx
What 2 structures make up the primordia of the face?
1st pharyngeal arch
Frontonasal prominence
What will the FNP develop into?
Forehead
bridge of nose
Philtrum
Nose
Fusion of what forms the intermaxillary segment?
What is the intermaxillary segment made of?
Medial nasal prominences
Philtrum, upper jaw (4 incisors) and the primary palate
Describe the development of the secondary palate.
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.
How does a cleft lip form?
Failure of fusion of the medial nasal prominence with he maxillary prominence
How does a cleft palate form?
2 possible issues with this?
Failure of the palatal shelves to fuse in the midline.
Feeding and speech difficulties
From where does the auricle develop?
How does it end up in line with the eyes?
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
Give some signs of FAS.
Underdeveloped jaw Thin upper lip Smooth philtrum Short nose Epicanthal folds Low nasal bridge Small head Flat midface
What does the lateral nasal prominence become?
Sides of the node
