10 Embryology 1 Flashcards
What is shown in this image?
Neural tube
Embryo at start of 4th week
What are the pharyngeal arches?
System of mesenchymal proliferations in the neck region of the embryo
5 in total (1,2,3,4,6) (NO 5)
Fill in the missing labels:
What is contained within/associated with each pharyngeal arch?
Artery
Nerve
Cartilage bar
(Muscles derived)
Fill in the missing labels:
Which cranial nerves supply each pharyngeal arch (1-6)?
1: CN V
2: CN VII
3: CN IX
4&6: CN X
(CN XI and CN XII have special relationship with pharyngeal arch system ( see embryology II)
What are the muscular derivatives of each pharyngeal arch?
- Muscles of mastication
- Muscles of facial expression
- Stylopharyngeus
- Cricothyroid, Levator palatini, Constrictors of pharynx
- Intrinsic muscles of larynx
What are each of the cartilage bars found in the individual pharyngeal arches precursors for?
The aortic arch lies in the floor of the pharynx. What happens to the aortic arches 1-6?
1&2 disappear
3 internal carotid
4 arch of aorta (L) and brachiocephalic artery (R)
6 pulmonary arch
Fill in the missing labels:
Identify the structures that develop from the endoderm lining the pharyngeal pouches.
- Tympanic cavity
- Palatine tonsils
- Parathyroid (inferior)
- Thymus
- Parathyroid (superior)
Which pharyngeal cleft is the only one that remains and what does it become?
1st cleft
Becomes external acoustic meatus
What happens to the rest of the pharyngeal clefts? (2-6)
2nd arch grows down to cover others- obliterates other clefts
What happens if there are remnants of clefts 2-6?
Branchial cysts / fistulae
What is contained within the frontal nasal prominence?
Cranial part of neural tube
What does the stomatodeum develop into?
Buccopharyngeal membrane
Fill in the missing labels:
What parts of the face do the:
FNP
Maxillary prominence
Mandibular porminence
develop into?
What are nasal placodes?
Thickening of ectoderm on frontal nasal prominence
How do the nasal prominences move closer together so that they eventually fuse in the midline?
Fill in the missing labels on the coronal section of the face during development :
Maxillary prominence gives rise to two palatal shelves
How does a lateral cleft lip form?
Failure of fusion of medial nasal prominence and maxillary prominence
What causes the formation of a cleft lip and a cleft palate?
Failure of fusion of medial nasal prominence and maxillary prominence AND combined failure of palatal shelves to meet in midline.
Describe and explain the effects of fetal alcohol syndrome:
Where do the following parts of the ear develop from?
- External auditory meatus
- Middle ear cavity
- Ossicles
- Auricles
- External auditory meatus
- 1st Pharyngeal cleft
- Middle ear cavity
- 1st Pharyngeal arch
- Ossicles
- 2nd Pharyngeal arch
- Auricles
- Proliferation within 1st and 2nd Pharyngeal arches surrounding meatus
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