Insemination

Key takeaways

Insemination belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Insemination to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Insemination from memory before moving on to harder problems.

Reference excerpt

Insemination is the introduction of sperm (in semen) into a female's reproductive system in order to fertilize the ovum through sexual reproduction. The sperm enters into the uterus of a mammal or the oviduct of an oviparous (egg-laying) animal. Female humans and other mammals are inseminated during sexual intercourse or copulation, but can also be inseminated by artificial insemination. In humans, the act and form of insemination has legal, moral and interpersonal implications. However, whether insemination takes place naturally or by artificial means, the pregnancy and the progress of it will be the same. Insemination may be called in vivo fertilisation (from in vivo meaning "within the living") because an egg is fertilized inside the body, this is in contrast with in vitro fertilisation (IVF).

Plants In plants, the fertilization process is referred to as pollination. It is the process of transfer of pollen grains from one anther to the stigma of other plants.

Natural insemination Insemination during sexual intercourse through penile–vaginal penetration is referred to as natural insemination (i.e., insemination by natural means). If an artificial lubricant needs to be used, care must be taken that it does not have spermicidal properties. During ejaculation, semen, containing male gametes known as sperm, is expelled from the penis through the male urethra into the moist and warm environment of the female reproductive tract. In humans, semen is usually ejaculated into the posterior vaginal fornix in direct contact with cervical mucus, though sperm may swim from other areas of the vagina or vulva to the cervix. The average volume of semen produced at ejaculation is 2 to 5 millilitres (about a teaspoon), containing an average of 182 million sperm. Only a small proportion of the sperm in each ejaculation reach the site of fertilization in the fallopian tubes, their numbers decreasing exponentially as they progress through the female reproductive tract. The majority of sperm either die in the acidic environment of the vagina or drip out with the semen. Prior to ovulation, the cervical mucus becomes thinner and more hospitable to sperm. Sperm swim rapidly into the uterus upon encountering cervical mucus, though many become lost in the cervical crypts where they either die or are delayed. Further attrition occurs in the uterus, where sperm are attacked by the female immune system. Only about 100–1000 sperm reach the fallopian tubes, where they may survive for up to six days. If ovulation occurs and the sperm encounter an ovum in the fallopian tube, fertilization may occur. A woman may also be naturally inseminated while having penile–vaginal intercourse for pleasure without any intent to conceive. This may be unintentional as a result of the failure of a barrier or behavioural method of contraception, or may be intentional if relying on female contraceptive methods or indifferent to the possibility of pregnancy. In most cultures, insemination by a male through sexual intercourse, whether the woman's husband, normal sex partner or not, is subject to social and sexual inhibitions and taboos, and has legal, moral and interpersonal implications. The term is also used in the context of third-party insemination, where a male who is not the woman's usual sexual partner (i.e., a sperm donor) fathers a child for the woman by providing his sperm through sexual intercourse rather than by providing his sperm for it to be used to produce a pregnancy in the woman by artificial means. The incidence of natural insemination by a sperm donor is usually a private matter, and may also carry greater health risks than where sperm has been processed by a fertility center. Advocates claim natural insemination generates higher pregnancy rates and a more 'natural' conception which does not involve the intervention and intrusion of third parties. However, it has not been medically proven that natural insemination has an increased chance of pregnancy. Additionally, conceiving through natural insemination is considered a natural process, so the father may be liable for child support and have custody and other rights of the child. The law usually draws a distinction between a man fathering a child by natural means, and a man who provides his sperm for it to be used to father a child by artificial means (i.e. by artificial insemination).

Artificial insemination

Artificial insemination is the introduction of sperm into the reproductive tract of a female by means other than sexual intercourse for the purpose of impregnating the female. In humans, artificial insemination may be used when a woman or her normal sex partner cannot, for any of a number of reasons, conceive by natural means. A number of artificial insemination strategies are available, including intracervical insemination (ICI) and intrauterine insemination (IUI). Compared with natural insemination, artificial insemination may be more invasive, and may require professional assistance and medical expertise, which will have a higher cost. ICI attempts to simulate natural insemination, without the sexual element. It is painless and is the simplest, easiest and most common method of artificial insemination; it can be performed in the home, either by the female on herself or with non-professional assistance. ICI involves the introduction of unwashed or raw semen into the vagina at the entrance to the cervix, usually by means of a needleless syringe. The sperm for insemination may be provided either by a sexual partner of the female's choice or by a sperm donor. Donor sperm is most commonly used by lesbian couples and single women, and by heterosexual couples when the male partner is suffering from male infertility. In some circumstances, sperm has been collected from males before they go off to war, or even right after they have died, and used to inseminate their female partners. In some countries, there are laws restricting and regulating who can donate sperm, who can receive artificial insemination, and what the legal consequences are of such insemination. Subject to any such restrictions, donor sperm is available to all women who want or need it. Women who live in a jurisdiction that prohibits them from being artificially inseminated may sometimes choose to obtain it by traveling to a jurisdiction that permits it. Artificial insemination has been and continues to be commonly used in livestock breeding as an efficient way of increasing production.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Insemination

Start with the simplest possible case. Write down what Insemination claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Insemination before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Insemination ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Insemination

In research: Insemination appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Insemination in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Insemination is common in secondary-school and first-year university syllabi. It links to neighbouring topics Animal sexuality, Reproduction in mammals, Semen, so understanding it makes those chapters shorter.
In everyday life: Look for Insemination outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Insemination in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Insemination means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Insemination out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Insemination in simple terms?

Insemination is the introduction of sperm (in semen) into a female's reproductive system in order to fertilize the ovum through sexual reproduction. The sperm enters into the uterus of a mammal or the oviduct of an oviparous (egg-laying) animal.

Why does Insemination matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Insemination?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Insemination.