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  • General

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  • 精精度

    Microscopic view showing sperm cells in a laboratory setting.

    How many sperm does it take to fertilize an egg?
    ::给鸡蛋施肥需要多少精子?

    85 million sperm per day are produced...per testicle. That's 170,000,000 every day. This means that a single male may produce more than a quadrillion (1,000,000,000,000) sperm in his lifetime! But it only takes one to fertilize an egg .
    ::每天产生8500万个精子...

    Production and Delivery of Sperm
    ::精子的生产和交付

    A sexually mature male produces an astounding number of sperm —typically, hundreds of millions each day! Sperm production usually continues uninterrupted until death, although the number and quality of sperm decline during later .
    ::一名性成熟的男性产生惊人数量的精子——通常每天数以亿计的精子! 精子生产通常会不间断地持续到死亡为止,尽管精子的数量和质量在以后会下降。

    Spermatogenesis
    ::子形起源

    The process of producing mature sperm is called spermatogenesis . Sperm are produced in the seminiferous tubules of the testes and become mature in the epididymis . The entire process takes about 9 to 10 weeks. 
    ::生成成熟精子的过程称为精子产生过程,精子在睾丸的半圆形管中产生,在相近时成熟,整个过程需要大约9至10周时间。

    If you look inside the seminiferous tubule shown in Figure , you can see cells in various stages of spermatogenesis. The tubule is lined with spermatogonia , which are diploid , sperm-producing cells. Surrounding the spermatogonia are other cells. Some of these other cells secrete substances to nourish sperm, and some secrete testosterone , which is needed for sperm production.
    ::如果您查看图中显示的半圆形管内, 您可以看到处于精子产生不同阶段的细胞。 管子与精子产生细胞相连接, 精子产生细胞。 围绕精子产生细胞是其它细胞。 还有一些细胞可以分泌精子, 以及精子生产所需的秘质睾丸酮。

    Cross-sectional view of seminiferous tubules, showing stages of sperm development and surrounding cells.

    Seminiferous Tubule. Cross section of a testis and seminiferous tubules.
    ::睾丸和半肾管的交叉部分

    Spermatogonia lining the seminiferous tubule undergo to form primary spermatocytes , which are also diploid. The primary spermatocytes undergo the first meiotic division to form secondary spermatocytes , which are haploid . Spermatocytes make up the next layer of cells inside the seminiferous tubule. Finally, the secondary spermatocytes complete to form spermatids . Spermatids make up a third layer of cells in the tubule.
    ::原始精精子细胞组成主要精子细胞,这些精子细胞也是低脂的; 主要的精子细胞组成第一层微米细胞组成次级精子细胞,这些精子细胞是低脂的; 精子细胞构成半营养管内的下一层细胞; 最后, 辅助精子细胞组成精子细胞; 精子细胞构成管内的第三层细胞。

    Sperm Maturation
    ::生长期 成熟期

    After spermatids form, they move into the epididymis to mature into sperm, like the one shown in Figure . The spermatids grow a tail and lose excess cytoplasm from the head. When a sperm is mature, the tail can rotate like a propeller, so the sperm can propel itself forward. in the connecting piece produce the energy (ATP) needed for movement . The head of the mature sperm consists mainly of the , which carries copies of the father’s . The part of the head called the acrosome produces that help the sperm head penetrate an egg.
    ::精子形成后,它们会进入顶端,成熟成精子,就像图中显示的那样。精子长尾部,从头部失去过多的细胞图层。当精子成熟时,尾部可以像螺旋桨一样旋转,这样精子可以向前推进。在连接的碎片中,精子可以产生运动所需的能量。成熟精子的头部主要由携带父亲的复制品的精子组成。头部的一部分叫做精子,可以帮助精子进入蛋中。

    Mature sperm cell showing structures: acrosome, tail, mitochondria, head, and connecting piece.

    Mature Sperm Cell. A mature sperm cell has several structures that help it reach and penetrate an egg. These structures include the tail, mitochondria, and acrosome. How does each structure contribute to the sperm’s function? (a) acrosome, (b) connecting piece, (c) tail, (d) head, (e) mitochondria.
    ::成熟精子细胞。 一个成熟的精子细胞有几个结构帮助它接触和穿透一个蛋。 这些结构包括尾巴、米托乔因德里亚(mitochondria)和杂技。 每个结构如何促进精子的功能? (a) 精子,(b) 连接片,(c) 尾巴,(d) 头部,(e) 米托乔因德里亚(mitochondria) 。

    Ejaculation
    ::射精

    Sperm are released from the body during ejaculation . Ejaculation occurs when muscle contractions propel sperm from the epididymis. The sperm are forced through the ducts and out of the body through the urethra . As sperm travel through the ducts, they mix with fluids from the glands to form semen . Hundreds of millions of sperm are released with each ejaculation.
    ::精液在射精期间从身体中释放出来,当肌肉收缩将精子从肾上腺中推进出来时,就会发生射精。精液被迫通过管子,通过尿道从身体中流出。精液穿过管子时,会与腺液混合,形成精液。数以亿计的精液随每次射精而释放出来。

      

     

    Summary
    ::摘要

    • Sperm are produced in the testes in the process of spermatogenesis.
      ::在精子产生过程中,精子在睾丸中产生。
    • Sperm mature in the epididymis before being ejaculated from the body through the penis.
      ::Sperm在肾上腺素中成熟,然后通过阴茎从身体中射出精液。

    Review
    ::回顾

    1. Outline the process of spermatogenesis. Name the cells involved in the process?
      ::概要描述精子产生过程。 参与过程的细胞名称 ?
    2. Where do sperm mature and how do they leave the body?
      ::精子在哪里成熟? 他们怎么离开尸体?
    3. If a man did not have functioning epididymis, predict how his sperm would be affected. How would this influence his ability to reproduce?
      ::如果一个人没有正常的直觉,请预测他的精子将受到何种影响。 这将如何影响他的繁殖能力?
    4. How does each mature sperm structure contribute to the sperm’s function?
      ::每个成熟精子结构如何促进精子的功能?