Embryology - Pharyngeal Apparatus Flashcards
What are the components of the pharyngeal apparatus?
Pharyngeal Cleft
Pharyngeal arches
Pharyngeal pouches
In the pharyngeal arches, what do the neural crest and paraxial mesoderm give rise to, respectively?
NC: CT components
Paraxial Mesoderm: Muscles
Each arch has its own ___________ and _______________.
cranial nerve and blood supply (aortic arch artery)
How many arches initially develop? How many are there in the end?
6 initially, but arch 5 regresses, leaving 1-4 and 6
The pharyngeal pouches are internal evaginations of what kind of pharyngeal _____________.
Endoderm
How many Pharyngeal pouches are there?
4
What are the skeletal derivatives of Arch 1?
1.– viscerocranium (malleus, incus) and connective tissues of face
What are the muscular derivatives of Arch1?
a. Muscles of mastication (temporalis, masseter, medial and lateral pterygoids)
b. Also: anterior belly of digastric, mylohyoid, tensor tympani, tensor veli palatini.
What nerve innervates Arch 1?
Trigeminal nerve (CN V3)
The oropharyngeal membrane develops between the two processes of the first arch. What is it composed of?
Outer layer of ectoderm and inner layer of endoderm
The oropharyngeal membrane ruptures by day 26 to allow communication between what structures?
Pharynx and oral cavity
What is the innervation of Arch 2?
Facial n.
What is the innervation of Arch 3?
Glossopharyngeal n.
What is the innervation os arch 4?
Vagus
What is the innervation of the fifth arch?
Slide says “mostly regresses”, so take away is who cares.
What is the innervation of Arch 6?
Vagus nerve, primarily by the recurrent larygeal nerve
The entire face comes from what arch?
Arch 1
What are the 3 prominences of Arch 1? What does this mean for the associated cranial nerve?
Frontal prominence
Maxillary prominence
Mandibular prominence
This is why the trigeminal nerve has three branches
What are the skeletal derivatives of Arch 2?
a. Stapes, styloid process of temporal bone
b. Stylohyoid ligament; lesser horn and superior portion of body of hyoid
What nerves contain SVE’s?
Trigeminal
Facial
Glossopharyngeal
Vagus
What are the muscular derivatives of Arch 2?
a. Muscles of facial expression
b. Also: stylohyoid, posterior belly of digastric, stapedius
Innervation of Arch 2?
Facial nerve, CN VII
What is the skeletal derivative of Arch 3?
1.greater horn and inferior portion of body of hyoid bone.
What is the muscular derivative of arch 3?
stylopharygneaus