Development Of Head And Neck Flashcards
Paraxial mesoderm (from somites and somitomeres) forms what?
All voluntary muscles of the craniofacial region, the dermis and connective tissue in this region.
What skeletal elements of the head is derived from neural crest cells?
Viscerocranium
What bony/cartilagenous elements are created by lateral plate mesoderm?
Laryngeal cartilages (cricoid and arytenoid)
Paraxial mesoderm forms what parts of the bony structures of the head?
Paraxial mesoderm
What separates the pharyngeal arches on the outside?
Pharyngeal clefts
What appears on the lateral wall of the pharynx?
Pouches
What tissues does the pharyngeal arches consist of?
Core: mesenchymal tissue
Outside: ectoderm
Inside: endoderm
What are the components of the first pharyngeal arch?
Consist of the maxillary and mandibular process.
Meckel’s cartilage —> incus and malleus
Premaxilla, maxilla, zygomatic bone, part of the temporal bone.
Muscles of mastication (masseter, temporalis and pterygoids), anterior belly of digastric, mylohyoid, tensor tympani, tensor palatini.
Nerve: mandibular branch of trigeminal.
First arch also contributes to the dermis of the face, sensory supply to the skin is by the trigeminal nerve.
Maxillary artery
What are the components of the second pharyngeal arch?
Reichert’s cartilage -> stapes, styliod process of temporal bone and stylohyoid ligament. Also upper part of hyoid bone.
Muscles: stapedius, stylohyoid, posterior belly of digastric, auricular, muscles of facial expression.
Nerve: facial nerve
Artery: hyoid and stapedial arteries
What are the components of the third pharyngeal arch?
Lower part and greater horn of hyoid bone
Stylopharyngeus
Nerve: glossopharyngeal
Artery: common carotid and first part of internal carotid
Contents of fourth and six arches
Thyroid, cricoid, arytenoid, corniculate and cuneiform
Muscles: cricothyroid, levator palatini and constrictors of the pharynx
Nerve: superior laryngeal nerve of the vagus
What arteries come from fourth pharyngeal arch?
Right: subclavian
Left: arch of aorta between common carotid and subclavian
What arteries comes from the sixth arch?
Right: right pulmonary artery
Left: left pulmonary artery and ductus arteriosus
What develops from first pharyngeal pouch?
Tubotympanic recess -> auditory tube
What forms in the first cleft?
External auditory meatus
