Both men and women have nipples and mammary glands, but usually only women have them develop at puberty.

男性和女性都有头和腺，但通常只有女性才会在青春期发育。

These lactotrophs secrete the hormone prolactin, and the increased levels of prolactin prepares the mammary glands to produce milk.

泌分泌催素，而催素水平增高使得腺可以产生汁。

When women breastfeed, they shed cells from the mammary gland into the milk.

当女性进行母喂养时，她们会将腺脱落到汁中。

So in the goat, it actually comes out, it's expressed in the mammary gland.

因此在山羊身上，它实际上是在腺中表达。

Using electricity, they transferred the mammary gland cell's nucleus into an egg cell from a second sheep.

他们将腺核转移到第二只绵羊卵中。

Like fur, this one's harder to see in the fossil record - we don't have any fossilized mammary glands.

就像毛发一样，这一点在化石记录中更难看到——我们没有任何腺化石。

Oxytocin causes cells that line the mammary glands to contract and is also known as the cuddle hormone, as it enhances the bonding experience between mother and child.

催产素促进排列腺收缩，也被称为拥抱激素，因为它增强了母亲和孩子之间联结体验。

Mammary glands eventually secrete the milk through the breasts, udders, or, in the rare case of the platypus, through ducts in the abdomen.

腺最终通过房、头或（罕见地如鸭嘴兽）通过腹部管道分泌汁。

It is admitted by most evolutionists that mammals are descended from a marsupial form; and if so, the mammary glands will have been at first developed within the marsupial sack.

大多数进化论者都承认哺动物是有袋类动物后代；如果是这样， 那么腺将首先在有袋动物袋内发育。

Her very entry to the world was groundbreaking – she was cloned using cells taken from another sheep's mammary gland as part of an experiment conducted by the Roslin Institute in Midlothian, Scotland.

她进入这个世界是开创性——她是使从另一只绵羊腺中提取进行克隆， 这是苏格兰中洛锡安罗斯林研究所进行一项实验一部分。

The development of the mammary glands would have been of no service, and could not have been affected through natural selection, unless the young at the same time were able to partake of the secretion.

腺发育将毫无处， 也不会受到自然选择影响，除非同时期幼崽能够分享腺分泌物。

The calcium is in the soil, it goes up into the plant, the cow gets hungry, it eats the plant, the calcium goes to the bloodstream, through the mammary glands and squirts out as milk.

钙在土壤中，它进入植物，母牛饿了，它吃植物，钙进入血液，通过腺并以牛奶形式喷出。

The mammary glands are common to the whole class of mammals, and are indispensable for their existence; they must, therefore, have been developed at an extremely remote period, and we can know nothing positively about their manner of development.

腺是所有哺动物共有， 是它们生存所不可或缺；因此，它们一定是在极其遥远时期发展起来， 我们对它们发展方式一无所知。