医学英语翻译

Introduction to the Developing Human

人体发育生物学介绍

Human development is a continuous process that begins when an oocyte (ovum) from a female is fertilized by a sperm (spermatozoon) from a male. Cell division, cell migration, programmed cell death, differentiation, growth, and cell rearrangement transform the fertilized oocyte, a highly specialized, totipotent cell, a zygote, into a multicellular human being. Although most developmental changes occur during the embryonic and fetal periods, important changes occur during later periods of development: infancy, childhood, adolescence, and early adulthood Development does not stop at birth. Important changes, in addition to growth, occur after birth (e.g., development of teeth and female breasts).

人体的发育是一个连续的过程。一开始，女性的卵子通过与男性的精子结合而完成受精，随后经过不断的细胞分裂、迁移、程序性死亡、分化、成熟和重排，受精卵这个高度特异性的全能细胞、合子，最终转变为一个多细胞组成的复杂的人体。尽管绝大多数的发育中的变化出现在胚胎和胎儿时期，一些重要的变化也发生在发育的后期如婴儿期、儿童时期、青少年期甚至早期成人期。发育并不会在人们出生后停止。一些重要的改变，不只是生长发育，也发生在出生以后（如牙齿和女性乳房的发育）。

1 DEVELOPMENTAL PERIODS

1 发育周期

It is customary to divide human development into prenatal (before birth) and postnatal (after birth) periods. During the prenatal period, the most visible advances occur during the third to eighth weeks of embryonic development. During the fetal period, differentiation and growth of tissues and organs occur. The rate of body growth increases during this period.

通常来说人体发育分为出生前阶段和出生后阶段。在出生前阶段，绝大数可见的发育变化出现在胚胎发育的第三周到第八周。而组织和器官的分化和成熟是在胎儿时期，此期人体的生长发育速度增快。

2 SIGNIFICANCE OF EMBRYOLOGY。

2 胚胎学的重要性

Literally, embryology means the study of embryos; however, the term generally

refers to prenatal development of embryos and fetuses.

胚胎学的表面意义是研究胚胎的科学，但实际上胚胎学涵盖了更广泛的整个胚胎以及胎儿的出生前发育。

Developmental anatomy is the field of embryology concerned with the changes that cells, tissues, organs, and, the body as a whole undergo from a germ cell of each parent to the resulting adult. Prenatal development is more rapid than postnatal development and results in more striking changes.

发育解剖学，从一个来自于父母双方的受精卵到一个成人，发育解剖学将细胞、组织、器官以及机体的变化联系成了一个整体。由于出生前发育远远快于出生后，因此这些变化十分惊人。

Teratology(Gr. teratos, monster) is the division of embryology and pathology that deals with abnormal development (birth defects). This branch of embryology is concerned with various genetic and/or environmental factors that disturb normal development and produce birth defects.

畸胎学，作为胚胎学和病理学的交叉科学，研究的是异常发育（出生缺陷）。这个胚胎学的分支关注的是扰乱正常发育产生出生缺陷的突变基因和（或）环境因素。

Embryology

·Bridges the gap between prenatal development and obstetrics, perinatal medicine, pediatrics, and clinical anatomy.

·Develops knowledge concerning the beginnings of human life and the changes occurring during prenatal development.

·Is of practical value in helping to understand the causes of variations in human structure.

·Illuminates gross anatomy and explains how normal and abnormal relations develop.

胚胎学

·填补了出生前发育和产科学、围产科学、儿科学、临床解剖学之间的空缺。·发现与人类生命起源、出生前发育变化相关的知识。

·对理解人体结构变异提供实用的帮助。

·阐明大体解剖学，解释正常结构与异常结构的关系及其发生。

Knowledge that physicians have of normal development and of the causes of anomalies is necessary for giving the embryo and fetus the greatest possible chance of developing normally. Much of the modern practice of obstetrics involves applied embryology. Embryologic topics of special interest to obstetricians are ovulation, oocyte and sperm transport fertilization, implantation, fetal-maternal relations, fetal circulation, critical periods of development, and causes of birth defects. In addition to caring for the mother, physicians guard the health of the embryo and fetus. The significance of embryology is readily apparent to pediatricians because some of their patients have birth defects resulting from maldevelopment, e.g., diaphragmatic hernia, spina bifida, and congenital heart disease.

临床医师掌握人体正常发育以及发育异常的原因是十分必要的，它利于医师指导处于胚胎期的生命以及胎儿向正常的方向发育。许多产科学的实践过程都离不开应用胚胎学。胚胎学对于产科学特别的关注点在于：排卵过程、卵子和精子的转运和受精、植入、胎儿与母体的关联、胎儿的血液循环、发育的关键时期以及导致出生缺陷的原因。除了对母亲的照料，产科医生同时守护着胚胎和胎儿的健康。胚胎学对产科医生的重要性是显而易见的，因为他们的病人出现出生缺陷如膈疝、脊柱裂、先天性心脏病，正是由于发育异常引起的，。

Developmental anomalies cause most deaths during infancy. Knowledge of the development of structure and function is essential for understanding the physiologic changes that occur during the newborn period and for helping fetuses and babies in distress. Progress in surgery, especially in the fetal, perinatal, and pediatric age groups, has made knowledge of human development even more clinically significant. Surgical treatment of the fetus is now possible.The understanding and correction of most congenital anomalies depend on knowledge of normal development and of the deviations that may occur. An understanding of common congenital anomalies and their causes also enables physicians, dentists, and other health care providers to explain the developmental basis of abnormalities, often dispelling parental guilt feelings.

发育异常是导致婴幼儿死亡的主要原因。人体结构功能发育的知识对于理解婴儿时期的生理变化和帮助处于病痛中的胎儿、婴儿必不可少。外科手术的发展，特别是在胎儿、围产期及儿科年龄人群的手术发展使得人体发育知识更具有临床

重要性。如今对于胎儿的外科手术已成为可能，了解和纠正绝大多数的先天畸形依赖于正常发育和可能产生的异常发育的知识，对于常见先天畸形及其原因的学习同时也使得内科医生、牙科医生以及其他保健医疗提供者可以向患者父母阐明疾病的发育基础，从而帮助父母消除对内疚的心情。

3 MOLECULAR BIOLOGY OF HUMAN DEVELOPMENT

3 人体发育的分子生物学

Rapid advances in the field of molecular biology have led to the application of sophisticated techniques (e.g., r ecombinant DNA technology, chimeric models, transgenic mice, and stem cell manipulation). These techniques are now widely used in research laboratories to address such diverse problems as the genetic regulation of morphogenesis, the temporal and regional expression of specific genes, and how cells are committed to form the various parts of the embryo. For the first time, we are beginning to understand how, when, and where selected genes are activated and expressed in the embryo during normal and abnormal development.

分子生物学领域的快速发展，使得一些先进技术得到广泛应用（如重组DNA 技术、嵌合模型、转基因小鼠和干细胞操作）。这些技术如今广泛应用于实验室研究以解决各种问题：如形态发生的基因调控、特殊基因的暂时区域性表达和胚胎细胞如何形成胚胎的各个部分。借助于这些技术，人们首次开始了解在正常以及异常的发育过程中，基因的选择性激活和表达是何时何地以及如何发生的。The first mammal, Dolly the sheep, was cloned in 1997 by Ian Wilmut and his colleagues using the technique of somatic cell nuclear transfer. Since then, other animals have been successfully cloned from cultured differentiated adult cells. Interest in human cloning has generated considerable debate because of social, ethical, and legal implications. Moreover, there is concern that cloning may result in infants born with birth defects and serious diseases.

1997年，Ian Wilmut和他的工作团队运用体细胞核移植技术完成了首个哺乳动物的克隆——Dolly羊。从此以后，其他动物也陆续地通过体外培养的成体分化细胞成功克隆。由于社会、伦理和法律问题，人类克隆的好奇心引发了大量的争论，另外也存在这样的担忧——克隆人类可能导致患有先天缺陷和严重疾病的婴儿的出生。

Human embryonic stern cells are pluripotential, capable of self-renewal, and are

able to differentiate into specialized cell types. The isolation and programmed culture of human embryonic stem cells hold great potential for the treatment of degenerative, malignancy, and genetic diseases.

人类胚胎干细胞具有多能性，既能完成自我更新，又能分化为其他特定的细胞类型。人类胚胎干细胞的分离和培养为退行性、恶性肿瘤性和遗传性疾病的治疗提供了可能。

4 DESCRIPTIVE TERMS IN EMBRYOLOGY

4 胚胎学的描述性术语

The English equivalents of the standard Latin forms of terms are given in some cases, e.g., sperm (spermatozoon). Eponyms commonly used clinically appear in parentheses, such as uterine tube (fallopian tube). In anatomy and embryology, several terms relating to position and direction are used, and reference is made to various planes of the body. All descriptions of the adult are based on the assumption that the body is erect, with the upper limbs by the sides and the palms directed anteriorly (Fig. 21A). This is the anatomical position. The terms anterior or ventral and posterior or dorsal are used to describe the front or back of the body or limbs and the relations of structures within the body to one another. When describing embryos, the terms dorsal and ventral are used (Fig. 21-3B). Superior and inferior are used to indicate the relative levels of different structures (Fig. 1A). For embryos, the terms cranial or rostral and caudal are used to denote relationships to the head and caudal eminence (tail), respectively (Fig. 1B). Distances from the source or attachment of a structure are designated as proximal or distal. In the lower limb, for example, the knee is proximal to the ankle and the ankle is distal to the knee.

一些术语除了标准的拉丁文形式还有同意的英语形式，如sperm (spermatozoon)。以人名命名的术语在临床运用中通常出现括号中，如uterine tube (fallopian tube)。在解剖学和胚胎学中，需要使用一些与位置、方向相关的术语，它的参考需要适应人体的各个位相。所有关于成人的描述都是基于假设人体处于直立、上肢放于两侧和手掌朝向前方的状态(Fig. 21A)。这是一个解剖位置。术语“前面的”或“腹侧的”以及“后面的”或“背侧的”用于描述人体的前面和背侧或是人体的四肢和相关结构的相对位置；当描述胚胎时，常用“腹侧的”和

“背侧的”(Fig. 21-3B)。“上方的”和“下方的”用于表示不同结构的相对水平(Fig. 1A)；对于胚胎，用术语“头端的”或“嘴侧的”和“尾端的”来表示相对于头端和尾端的位置关系(Fig. 1B)。相对于一个结构的距离用“近端的”和“远端的”来表示，如对于下肢，膝关节相对踝关节处于近端而踝关节相对膝关节处于远端。

The median plane is an imaginary vertical plane of section that passes longitudinally through the body. Median sections divide the body into right and left halves (Fig. 1C). The terms lateral and medial refer to structures that are, respectively, farther from or nearer to the median plane of the body. A sagittal plane is any vertical plane passing through the body that is parallel to the median plane (Fig. 1C). A transverse (axial) plane refers to any plane that is at right angles to both the median and coronal planes (Fig. 1D). A frontal (coronal) plane is any vertical plane that intersects the median plane at a right angle (Fig. 1E) and divides the body into anterior or ventral and posterior or dorsal parts.

正中矢状平面是一个假想的经过人体纵轴的矢状平面，正中平面将人体分为左右两部分(Fig. 1C)。术语“外侧的”和“内侧的”是指所指结构相对于正中平面较远或较近。矢状平面是指任何一个平行于正中矢状平面的经过人体的垂直平面(Fig. 1C)。横断面（轴面）是指任何一个与正中平面以及冠状面成直角的平面(Fig. 1D)。冠状面是指任何一个与矢状平面垂直的平面(Fig. 1E)，它将人体分为前（腹侧）以及后（背侧）两部分。

Figure 1 Drawings illustrating descriptive terms of position, direction, and planes of the body. A, Lateral view of an adult in the anatomical position. B, Lateral view of a 5-week embryo. C and D, Ventral views of 6-week embryo. E, Lateral view of a 7-week embryo. In describing development, it is necessary to use words denoting the position of one part to another or to the body as a whole. For example, the vertebral column (spine) develops in the dorsal part of the embryo, and the sternum (breast bone) in the ventral part of the embryo.

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图1 图片说明了描述人体体位、方向和平面的术语。A成人解剖位置侧面观B五周胚胎侧面观C和D六周胚胎腹侧面观E七周胚胎侧面观。在描述发育时，需要使用表明一个部位相对于其他部位或是整个身体的术语，如脊柱在胚胎背侧产生，而胸骨产生于胚胎的腹侧。