Sexual stimulation

Sexual stimulation is anything that leads to sexual arousal or orgasm. This thing can be physical or of other senses, and is known as a stimulus.

Sexual stimulation is a broad term, usually understood to mean physical touching of the genitals or other body parts. The term can, however, include stimuli affecting the mind (sexual fantasy), or senses other than touch (such as sight, smell, or hearing). Sufficient physical stimulation of the genitals usually results in an orgasm. Stimulation can be by oneself (masturbation or sexual fantasy) or by a sexual partner (sexual intercourse or other sexual activity), by use of objects or tools, or by some combination of these methods.

Some people practice orgasm control, whereby a person or their partner controls the level of stimulation to prolong the experience leading up to orgasm.

Sexual intercourse, also referred to as sex, can be traced back to as early as 2 billion years ago, starting with algae and plants. Through fossilized remains of fish embryos, evidence of sexual intercourse similar to that of humans can be found. Whether pleasure was possible amongst species like plants and fish is yet to be determined, but humans have been able to have sex and, in turn, pleasure their partners. This could have started off as a way for the female to get the required reaction from a male in order to become pregnant, but the pleasure from this experience became part of, if not a main reason why, humans have continued to have sex.

As for sexual stimulation, it is only relatively recent that this topic has been studied further. While sex might have always been pleasurable, the way society has treated sex has affected the dialogue surrounding sex. In some civilizations, such as Ancient Rome, sex was used for both pleasure and reproduction, depicted in many forms of art, and was also practiced using restraint and modesty. In the Middle Ages, religious factors affected the way people viewed sex, causing many to abstain out of fear of falling into sin. During these times, hygiene was also poor and plumbing systems were barely there, if at all, which caused disease to be a contributing factor in abstinence. Around the late 1800s to the mid 1900s, the act of sex was not only beginning to surge, but also sex on different levels was being studied. This led to more researchers learning about sexual practices in different cultures, the age when sexual tendencies begin to emerge, factors that affect sex and desire, and the variations in sexual arousal and behaviors.

Since then, sex has been more openly talked about, though it is still not something many are open about. However, research is still being done, and behaviors that were previously seen as shameful (e.g. BDSM, homosexuality, polyamory) are being studied further, which has changed how people see sex and the actions involved that can make it more pleasurable.

Physical sexual stimulation consists of touching the genitals or other erogenous zones.

Masturbation, erotic massage, and manual sex are types of physical stimulation involving the genitals. This stimulation is usually from sensitive touch receptors in the skin or other erogenous zones, which detect when they're being touched. Arousal is triggered through these receptors in these body parts, which cause the release of pleasure-causing chemicals (endorphins) that act as mental rewards to pursue such stimulation. Someone may become aroused by simply touching another person, though the bulbocavernosus reflex only occurs when a sexual organ (penis or clitoris) is stimulated.