Section 3 Medical Literature 第三部分 医学文献
Part 1.
M.T.，a 60-year-old gravida1) 2,parturition 2,had spent three months under the care of her gynecologist for treatment of postmenopausal bleeding and cervical dysplasia2).She had had several vaginal examinations with Pap smears3),a uterine ultrasound,colposcopy with endocervical biopsies4)，and a D&C with cone biopsy.She wanted to take a hormone replacement therapy，but her doctor thought she was at too much risk with the abnormal cells on her cervix and the excessive bleeding.
She had a Total Abdominal Hysterectomy5)(TAH)and Bilateral Salpingo-Oophorectomy6)(BSO)under general anesthesia with no complications and an uneventful recovery.Her uterus had been prolapsed on abdominal examination，but there was no sign of malignancy or Pelvic Inflammatory Disease7)(PID).The pathology report reviewed several uterine leiomyoma and stenosis of the right uterine tube.She was discharged on the second postoperative day with few activity restrictions.
注释：
1）gravida［ˈgrævidə］孕妇
2）cervical dysplasia 宫颈非典型增生
3）Pap smears 子宫颈抹片检查，宫颈涂片（巴氏图片，子宫颈或阴道所采集的细胞的研究，用于癌症的早期检测，也被称为Papanicolaou smear或Pap test）
4）colposcopy with endocervical biopsies 子宫颈活检阴道镜检查
5）total abdominal hysterectomy 经腹全子宫切除术
6）bilateral salpingo-oophorectomy 双侧输卵管卵巢切除术
7）pelvic inflammatory disease 盆腔炎
Part 2.
Anatomically,the male and female reproductive systems consist of both internal organs and external structures that are involved in the production of gametes1),delivery or reception of gametes，and the support of the growing embryo/fetus.
Like the urinary system，the reproductive system develops from intermediate mesoderm2).Part of the urogenital ridge that develops from this mesoderm will form the gonadal ridge.This is the structure that the male testis and the femal ovaries develop from.
Between 7 and 8 weeks developmentally，the gonadal ridge will differentiate into testes or ovaries.The mesonephric ducts(of the developing kidneys)and the paramesonephric ducts3) will develop into the other associated reproductive organs.
If testes develop,the paramesonephric ducts degenerate and the mesonephric ducts become the epididymis，ductus deferens，and ejculatory ducts.If ovaries develop,the mesonephric ducts degenerate and the paramesonephric ducts become the uterine(fallopian)tube，uterus，and the superior vagina.
The external genital of both sexes develop from the genital tubercle.In both sexes，the gonads must descend from the lumbar region(where they develop)into the lower pelvic cavity.In males the testes actually descend through the anterior body wall(inguinal canal)and liein the external sac-like scrotum.Normal sperm development requires lower temperatures than inside the body cavity.This traversing of the body wall accounts for the higher incidence of hernias in males.
注释：(https://www.daowen.com)
1）gametes 配子
2）intermediate mesoderm 间质中胚层
3）paramesonephric ducts 副中肾管，中肾旁管
Part 3.
Gestation When the pronuclei1)(called pronuclei because they are haploid2))of the sperm and ovum unite,a zygote3) is formed.This fertilized egg or zygote immediately begins to divide.The cells do not entirely separate but form a cleavage4).The result is a ball of cells called a morula5).At the same time a developing cavity,the blastocele6)，forms a blastocyst，which consists of an inner cell mass,the future embryo,and an outer layer,the trophoblast7) or primitive placenta.By the second week the blastocyst attaches itself to the uterine wall by fixing chorionic villi from the chorion membrane into the uterine wall.Meanwhile，a fluid-filled membrane，the amnion，also develops.Next，two cell layers develops in the embryo，the ectoderm and endoderm.Finally，a middle layer,the mesoderm，develops.These three cell layers are called the primary germ layers，and they begin to form specialized tissues(histogensis)that will become body organs and structures.At this time the embryo begins to form body shapes(morphogenesis).As tissue differentiation proceeds，the cells of the ectoderm，mesoderm，and endoderm produce the linings of all systems.
Extraembryonic structures—the yolk sac，amnion，chorion，and allantois—sustain and protect the fetus.Blood vessels develop in the yolk sac and in the early stages provide the embryo with nourishment.For protection，the embryo is enclosed in a fluid-filled sac，the amnion.The chorion gives rise to much of the placenta，which is the organ of communication between the mother’s blood vessels and fetal stage of pregnancy lasts from the third month to birth.During this period the body structures develop and growth of the fetus continues.
Childbirth Parturition is the expulsion of the fully developed fetus from the uterus.There are three stages lasting several hours.
First stage:The progesterone8) level is decreased and the uterus begins to contract，pushing the fetus downward and causing the cervix to dilate.
Second stage:Labor pains become more frequent and severe.Finally，the infant is expelled head first.Sometimes and episiotomy is performed to prevent the infant from tearing through the perineum.
Third stage:Ten to thirty minutes after the birth the placenta is expelled.
注释：
1）pronuclei 原核，前核（pronucleus的复数形式）
2）haploid 单倍体
3）zygote 受精卵，结合子
4）cleavage 劈开，分裂，卵裂
5）morula 桑葚胚（复数形式为morulae）
6）blastocele 囊胚腔，分裂腔
7）trophoblast 滋养层，滋养细胞
8）progesterone 孕酮，黄体酮