Add Ons

Front 1

During the seventh week of gestation, what develops?

Back 1

-face has a more human appearance
-eyes approach the front of the face, and the nose represents less of the face than it did at the fourth week
-lateral growth of the brain, resulting in facial expansion, causes the eyes to appear on the front of the face, which makes it more recognizable as a human face
-a third of the face has been added lateral to each nostril
-eyes are on the same horizontal plane as the nostrils, which will change after the bridge of the nose develops and lengthens
-the upper lip has fused, producing a medially located philtrum
-mouth is limited in size with the change in facial proportions
ear hillocks have fused and grown to form the ears (auricles)
-ridges around the eyes will soon develop into eyelids
-the danger of a cleft lip has passed
-in just three prenatal weeks, seperate tissue masses have enlarged, fused, and merged into a recognizable human face

Front 2

Causes of facial and palata clefts are:

Back 2

-environmental factors
-genetic factors
-combonation of both

Front 3

The face develops primarily from tissues surrounding the ____ ____.

Back 3

oral pit (stomodeum)

Front 4

Lying inferior to the mandibular arch is the second pharyngeal or ______ arch, and its muscles expand into and contribute to the face.

Back 4

hyoid

Front 5

The hyoid arch also forms part of the ______ and ______ ear.

Back 5

external, middle