Embryology Flashcards
Name the organ that arises from the same pharyngeal pouch as the thymus.
Inferior parathyroids
Where do the voluntary muscles of the tongue originate?
Occipital somites
Describe the primary palate and name the structure from which it arises.
Medial nasal prominence
The anterior two thirds of the tongue are derived from which pharyngeal arch.
1st
Cleft lip occurs when the ______ fails to fuse with the ______.
Maxillary prominence, medial nasal prominence
Lateral cervical cysts are commonly located____________.
Anterior to the SCM
How many Pharyngeal arches are there?
How many Pharyngeal pouches?
How many Pharyngeal grooves?
What is significant about the fifth arch?
- There are fice arches (1,2,3,4,6)
- There are 4 pharyngeal pouches (1,2,3,4)
- There are 4 pharyngeal grooves (1,2,3,4)
Pharyngeal arch 5 has completely regressed along with the fifth branch of the aortic arch that it would have formed.
What are the pharyngeal arches made of?
Somite mesoderm and neural crest cells
Somite mesoderm forms muscles and arteries
Neural crest cells form bone and connective tissue
What is the thyroid formed from?
On adults what indicates the thyroglossal duct?
Thyroid diverticulum which migrates caudally passing the ventral hyoid bone and remains connected to the tongue by the thyroglossal duct.
Foramen secum
What cranial nerve comes from the first arch?
What is the adult derivitave of the mesoderm?
What is the adult derivitive of the Neural crest?
5
Muscles of mastication, mylohyloid, anterior digastric, tensor palentini, tensor tympini
Menkels cartlidge, maxilla, mandible, incus, malleus, zygomatic bone, squamous temporal bone, sphenomandibular ligament,
What cranial nerve comes from the 2nd arch?
What is the mesoderm derivitave?
What is the neural crest derivitive?
CN7
Muscles of facial expression, posterior digastric stylohyloid, stapedus
Hyloid Arch, Stapes, styloid process, stylohyloid ligament, lesser horn and upper body of the hyloid ligament
What CN comes from the third arch?
Mesoderm derivitive?
Neural Crest Derivitive?
9
Styopharyngeus, common carotid arteries, internal carotid arteries
Greater and Lower Horn of the Hyloid Bone
What CN comes from the 4th arch?
Mesoderm Derivitive?
Neural crest derivitive?
CN10 (Inferior Laryngeal)
Muscles fo the soft pallate , pharynx, cricopharyngeus, laryngeal cartlidge, subclavian artery, aortic arch
No neural crest derivitive
What CN comes from the sixth arch?
CNX (Superior Laryngeal)
Intrinsic muscles of the larynx, upper muscles of the esophagus, laryngeal cartlidge, pulmonary arteries, ductus arteriosus
What is derived from the first pouch?
Epithelial lining of the auditory tube, middle ear cavity and mastoid air cells
First pouch has half ectoderm and half endoderm