Face and Neck Development Flashcards
The face and its associated tissue begin to form during the ___ of prenatal development
fourth week within the embryonic period
Facial development will be completed in the
twelfth week within the fetal period
During the ____ week when the face and associated tissues are forming, the rapidly growing brain of the embryo
fourth through the 12th; bulges over the oropharyngeal membrane and developing heart
The area of the future face is squeezed between
the developing brain and heart with the formation of the three embryonic layers and resultant embryonic folding
____embryonic layers are involved in facial development
the ectoderm, mesoderm, and endoderm ( All three)
Facial development includes formation of:
- the primitive mouth
- mandibular arch
- maxillary process
- frontonasal process
- nose
Facial development depends on the five major facial processes (or prominences) that form during the fourth week and surround the primitive mouth of the embryo:
- one frontonasal process
- paired maxillary processes
- paired mandibular processes
The development of the associated oral structures is occurring at the same time as
facial development
Most of the facial structures develop by the fusion of
swellings (tissues) on the same surface of the embryo
Most of the facial structures develop by the fusion of swellings (tissues) on the same surface of the embryo. ___ is initially located between these adjacent swellings
A cleft (or furrow)
In some cases,____ maybe left on the facial surface, showing where the fusion of the swellings took place.
a slight groove or line
with most facial fusion, these furrows left from fusion of swellings on the same surface or the embryo are usually eliminated as the
underlying mesenchyme migrates into the furrow making the embryonic facial surface smooth
fusion of swellings (tissues) on the same surface of the embryo process differs from that of the neural tube, upper lip, and palatal fusion, which is the
fusion of two separate structures from two different surfaces
Upper lip and palatal fusion involves the fusion of
swellings or tissue from different surfaces of the embryo, such as that which occurs with the fusion of the neural tube
At the beginning of the__ week, the primitive mouth has become the
fourth; stomodeum
The stomodeum initially appeared as a
shallow depression in the embryonic surface ectoderm at the cephalic end before the fourth week
Initially, The stomodeum is limited in depth by
the oropharyngeal membrane (which developed during the third week)
The oropharyngeal membrane also separates the stomedeum from the
primitive pharynx
The primitive pharynx is the____ of the foregut which is the____ of the future digestive tract
cranial part; beginning
In the___ week, the oropharyngeal membrane
latter part of the fourth; disintegrates. With this disintegration, the primitive mouth is increased in depth and enlarges in width across the surface of the midface
Within the_____ week, two bulges of tissue appear inferior to the primitive mouth:
fourth; the two mandibular processes
the two mandibular processes consist of
a core of mesenchyme formed in part by NCCs that migrated to the facial region.
the two mandibular processes Is Covered ___
externally by ectoderm and internally by
endoderm
The paired mandibular processes fuse at the midline to form
The mandioular arch