早期胚胎面部发育

Early Embryonic Facial Development安徽中医药大学第一附属医院耳鼻喉科金龙

早期胚胎面部发育

The facial features of the human embryo develop rapidly very early on in pregnancy beginning around the 4th week after conception.

从怀孕后第4周开始，人类胚胎的面部特征在怀孕的早期就迅速发展

Many of the structures of the face originate from a group of cells called Cranial Neural Crest Cells.

面部的许多结构都来自称为颅神经嵴细胞的一组细胞。

These cells move in a distinct pattern from the neural tube located in the back of the embryo to create the various structures of the face.

这些细胞以与位于胚胎后部的神经管不同的模式运动，从而形成面部的各种结构。

Aberrations in the formation or behavior of these cells are the main causes of abnormalities in the head and face.

这些细胞的形成或行为异常是头部和面部畸形的主要原因。

During the first three days of development,the fertilized ovum, or egg, is located in the Fallopian tube.

在发育的前三天，受精卵或卵子位于输卵管中。

As it travels down the tube, it undergoes rapid divisions to form a cluster of cells called the morula.

当它沿输卵管下行时，它经历快速分裂形成一簇细胞，称为桑葚胚。

These cells then organize themselves to form the blastocyst and by the end of week 5,the fully formed blastocyst comes into contact with the uterine wall for implantation.

这些细胞组织起来形成胚泡，在第5周结束时，完全形成的胚泡与子宫壁接触，准备着床。

During the second week of development, the inside of the blastocyst known as the embryoblast,becomes two layers, the hypoblast and the epiblast layers.

在发育的第二周，胚泡内的成胚细胞分为两层:内胚层和外胚层。

Together these layers form oval-shaped disc-like structure.

这些层合在一起形成了椭圆形的圆盘状结构。

In the third week development,a streak is created on the surface of the epiblast,during which time, the cells of the epiblast detach and migrate.

在发育的第三周，外胚层表面形成一条条纹，在此期间，外胚层细胞分离和迁移。

These migrating cells create three layers, the ectoderm, mesoderm and endoderm layers,which go on to contribute cells to form all the tissues and organs in the human body.

这些迁移的细胞创造了三层，外胚层、中胚层和内胚层，它们继续贡献细胞来形成人体的所有组织和器官。

In the third to fourth weeks of development a cord called the notochord is formed.

在发育的第三至第四周，脊索形成。

This induces the cells in the overlying ectoderm to thicken forming a region called the neural platealong the back at the embryo.

这导致覆盖外胚层的细胞增厚，形成一个沿着胚胎背部的神经板。

The edges of the neural plate elevate to form the neural folds, that eventually fuse to form the neural tube

神经板的边缘升高以形成神经褶皱，最终融合形成神经管

During this process neural crest cells are formed along the entire length of the tube at the tip of the folding neural folds.

在这一过程中，神经嵴细胞沿着整个管的长度在折叠神经褶皱的尖端形成。

Neural crest cells formed from the head, or cranial region, are called Cranial Neural Crest Cells, or CNCC's

由头部或颅区形成的神经嵴细胞称为颅神经嵴细胞，简称CNCC

These cells multiply and soon start migrating over long distances in distinct paths,from the back of the embryo towards the front of the embryo.

这些细胞繁殖并很快开始以不同的路径长距离迁移，从胚胎的背面迁移到胚胎的前面。

Once they arrive at their target destinations in the facial regions，CNCC's further develop and mature and ultimately contribute to a substantial amount that the structures in the head and neck region such as bones, cartilage and nerves.

一旦它们到达了面部区域的目标目的地，CNCC就会进一步发展和成熟，并最终对头颈部的骨骼、软骨和神经等结构做出大量贡献。

Growth migration and subsequent differentiation of CNCC's are critically important for proper development of the normal structures of the facial region.

生长迁移和CNCC的后续分化对面部正常结构的正常发育至关重要。

Soon after the CNCC's reach their final destination，the facial structures begin to take shape externally.

CNCC到达目的地后不久，面部结构开始在外部形成。

By the fourth week of development the embryo is characterized by five facial swellings,the frontonasal prominence and the paired maxillary and mandibular prominences these structures are formed in part from the migration and proliferation of the CNCC's from different regions of the neural tube.

在发育的第四周，胚胎的特征是5个面部隆起，额窦突出和成对的上颌和下颌突起，这些结构部分是由来自神经管不同区域的CNCC的迁移和增殖形成的。

In a five-week-old embryo the nasal placodes which will go on to become the olfactory system and the optic placodes which will become the lenses of the eyes will form.

在一个五周大的胚胎中，嗅基板将形成嗅觉系统，而视觉基板将形成眼睛的晶状体。

in addition the maxillary and mandibular prominences enlarge and grow forward and towards the middle eventually giving rise to the upper and lower jaws respectively.

此外，上颌和下颌的突起扩大并向中间生长，最终分别形成上颌和下颌。

In a six-week-old embryo the two mandibular prominences fuse to form the lower jaw At this point the outline of the mouth is visible.

在一个六周大的胚胎中，两个下颌的突起融合在一起形成了下颌，这时可以看到嘴的轮廓。

In the seven-week-old embryo the maxillary prominences grow and fuse to form the border of the nostril and the upper lip.

在7周大的胚胎中，上颌骨突起生长并融合形成鼻孔和上唇的边界。

Merging of the maxillary and mandibular prominences forms the cheeks and the corners at the mouth.

上颌骨和下颌的突起形成了脸颊和嘴角。

The philtrum of the upper lip and palate are also created at this time

人中和上腭也在这个时候形成

In this flurry of activity in the first seven weeks after fertilization the five facial prominences give rise to the formation of the forehead and sides of the face,middle and sides of the nose, the philtrum, the upper lip the palate and the lower jaw.

在受精后的前七周，在这一连串的活动中，五个面部隆起形成了前额和脸的两边、鼻子的中间和两边、人中、上唇、上颚和下颌。

By the seventh week of human embryonic development,most of the facial structures can be observed.

在人类胚胎发育的第七周，可以观察到大多数面部结构。

In the next few months of development the initial cartilaginous skeleton of the face is replaced by bone and there is an overall increase in shape and size of the different structures of the face.

在接下来几个月的发育过程中，面部最初的软骨会被骨骼所取代，面部不同结构的形状和大小也会整体增加。

From childhood to adulthood the face continues to develop through further growth and remodeling.

从童年到成年，脸部会通过进一步的成长和重塑而不断发展。