Pharyngeal Apparatus Flashcards
Pharyngeal Apparatus
Contribute to the formation of the head and neck. Includes face,neck,mouth,larynx,pharynx and neck.
Pharyngeal apparatus starts to develop when?
4 week old embryo.
what are the contents pharyngeal apparatus?
pharyngeal arches, pouches,grooves, membranes
Pharyngeal arches begin to develop when and where?
first part of 4th week. Begin at lateral wall of the cranial end of the foregut(primordial pharynx)
Pharyngeal arches are what in origin?
Neurocrest in origin
Stomodeum
anterior end of the foregut- site of future mouth
Pharynx narrows inferiorly and forms?
The esophagus
Oropharyngeal membrane separates?
The primordial pharynx and the foregut from the amniotic cavity
Oropharyngeal membrane ruptures when?
26th day - allowing foregut to communicate with the amniotic cavity.
4 pairs of well developed arches by?
end of 4th week
Arches separated on the outside by? on the inside?
Pharyngeal grooves and on the inside by pharyngeal pouches.
What does an arch consists of?
a core of mesenchyme(embryonic connective tissue from neurocrest cells) covered externally by ectoderm and internally by endoderm
whats embedded in the mesenchyme
Blood vessel-artery,cartilage-forms the skeletom of structures from arch,muscular component- gives rise to some muscles of head and neck,nerve- supplies mucosa and muscles derived from arch.
First Arch
known as mandibular arch, develops two prominences - maxillary and mandibular prominence. Muscles include mylohyoid,anterior belly of digastric,tensor tympani and tensor veli palatini. Nerve is Cranial Nerve V- Trigeminal
Second Arch
Known as Hyoid Arch. Major contribution to formation of hyoid. Muscles include stapedius,stylohyoid,posterior belly of digastric, and muscles of facial expression. Nerve is CN VII - Facial
