Male Ejaculation

Ejaculation is the discharge of semen during a male orgasm. While other reasons for ejaculation may occur, it usually occurs in the final stage of orgasm for a male. Ejaculation generally occurs in spurts directly after the male feels the initial sensation of an orgasm. Once the male has ejaculated, the head of the penis…

Evolution and Human Sexuality

Evolution is defined as the change in frequency of certain traits across generations. The accumulation of new traits may lead to new characteristics or even new species over time. This means that, with time, enough changes can lead to the formation of a new species. Evolution is a continuous, extremely gradual process that has created…

Pre-cum (Cowper’s Secretions)

Pre-cum, otherwise known as pre-ejaculatory fluid, is a clear, sticky fluid secreted by the penis during sexual arousal. Pre-cum is different from semen, as it is produced by the Cowper’s glands, and while pre-cum rarely carries sperm, it is usually not enough to cause pregnancy. Pre-cum is capable of transmitting sexually transmitted infections (STIs) like…

The Biology of Reproduction

Every organism must reproduce (create offspring) in order to pass a part of themselves on into future generations. Depending on the organism, it can either reproduce using sexual or asexual reproduction, which both involve cell division. The parental traits of sexually reproducing organisms will also mix to form a unique combination in the offspring, and…

Male Infertility

Disclaimer Note: While both males and females can be infertile, this article focuses on male infertility, it’s most common causes and treatments. For information on female infertility click here. Infertility is when a male and female partner cannot successfully conceive a child after a year of frequent, unprotected intercourse. Male and female infertility are each responsible…

Female Infertility

Disclaimer note: While both males and females can be infertile, this article focuses on female infertility, its most common causes, and treatments. For information relating to male infertility click here. Overview of Female Infertility Female infertility is defined as the inability to conceive or carry a pregnancy to term after 12 months of unprotected intercourse, or…

How to Increase the Chances of Pregnancy

Some couples are able to get pregnant effortlessly, while others experience varying degrees of difficulty. Many couples who are trying to conceive are anxious to do so. Although having intercourse within the “fertile window” is one of the best known ways to increase the probability of fertilization, there are several other ways that couples can…

Sperm

Sperm are the male reproductive cells found in semen. When mature and motile, they are referred to as spermatozoa (singular: spermatozoon). In humans, sperm cells ideally contain 23 chromosomes (half of a human’s genetic material) and may combine with the 23 chromosomes contained in a female’s ovum during fertilization to form a new human being.1 A…

Male Sterilization

Male Sterilization A vasectomy is a permanent method of birth control for males. It is a surgical procedure, typically involving local anesthesia, in which the vas deferens are cut, tied, or blocked off so that sperm cannot leave the scrotum. This procedure prevents the expulsion of sperm from the male’s body during ejaculation, thus eliminating…