Pharyngeal arches Pharyngeal pouches Pharingeal grooves/cleft

88 Pages·2013·2.59 MB·English

by  Ferri Widodo

Pharyngeal arches Pharyngeal pouches
Pharingeal grooves/cleft [Pharyngeal membrane]
• The pharyngeal arches contribute extensively to the
formation of the face, nasal cavities, mouth, larynx,
pharynx, and neck
• @ punya arteri & saraf cranial
• Pada manusia ada 5, karena yg ke-5 regresi
• 1 &2 s.d midline
• Makin caudal makin pendek
• Dipisahkan satu sama lain oleh
– Pharyngeal pouch [internal]
– Pharygeal grooves [external]
Pharyngeal arches
• Permukaan luar ditutupi ectoderm
• Permukaan dalam (pharyngeal) oleh
endoderm; kcl 1st arcus oleh ectoderm
• INTI : sel Neural Crest , dg sekitarnya
dikelilingi mesoderm.
• @  diff:
– Mesoderm  otot, pembuluh darah*
– CNC  tulang, cartilago, jaringan ikat.
Pharyngeal arches
The first pharyngeal arch (mandibular arch)
= Meckel cartilage
separates into two prominences :
– The maxillary prominence gives rise to the maxilla,
zygomatic bone, and a portion of the vomer .
– The mandibular prominence forms the mandible. The
proximal mandibular prominence also forms the
squamous temporal bone (os temporalis).
Pharyngeal arches
• The dorsal end of the first pharyngeal arch cartilage :
– Early in development, small nodules break away
from the proximal part of this cartilage and form
malleus and incus.
– The middle part of the cartilage regresses, but its
perichondrium forms the anterior ligament of
malleus and the sphenomandibular ligament.
• Ventral parts  primordium of the mandible
The cartilage  intramembranous ossification
Pharyngeal arches
Pharyngeal arches
1st arch
- Tdd processus maxillar [dorsal] & mandibular
[ventral]
Pharyngeal arches
The second pharyngeal arch (hyoid arch)
 os hyoid, (along with parts of the third and fourth
arches)
• During the fifth week, the second pharyngeal arch
enlarges and overgrows the third and fourth arches,
forming an ectodermal depression-the cervical sinus
• An independent cartilage anlage near Pharyngeal arches
the dorsal end of the second
pharyngeal arch cartilage (Reichert
cartilage), ossifies to form the stapes of
the middle ear and the styloid process
of the temporal bone
• The part of cartilage between the
styloid process and hyoid bone
regresses; its perichondrium forms the
stylohyoid ligament
• The ventral end of the second arch
cartilage  lesser cornu (Latin, horn)
and the superior part of the body of
the hyoid bone
Pharyngeal arches
Pharyngeal arches
• Muscles of the hyoid arch :
– the stapedius,
– stylohyoid,
– posterior belly of the digastric,
– auricular, muscles of facial expression.
• The facial nerve, the nerve of the second arch,
supplies all of these muscles.