Human reproductive system in the context of "Sexual relations"

Sexual and reproductive health (SRH) is a field of research, health care, and social activism that explores the health of an individual's reproductive system and sexual well-being during all stages of their life. Sexual and reproductive health is more commonly defined as sexual and reproductive health and rights, to encompass individual agency to make choices about their sexual and reproductive lives.

The term can also be further defined more broadly within the framework of the World Health Organization's (WHO) definition of health―as "a state of complete physical, mental and social well-being, and not merely the absence of disease or infirmity"―. WHO has a working definition of sexual health (2006) as '"…a state of physical, emotional, mental and social well-being in relation to sexuality; it is not merely the absence of disease, dysfunction or infirmity. Sexual health requires a positive and respectful approach to sexuality and sexual relationships, as well as the possibility of having pleasurable and safe sexual experiences, free of coercion, discrimination and violence. For sexual health to be attained and maintained, the sexual rights of all persons must be respected, protected and fulfilled." This includes sexual wellbeing, encompassing the ability of an individual to have responsible, satisfying and safe sex and the freedom to decide if, when and how often to do so. UN agencies in particular define sexual and reproductive health as including both physical and psychological well-being vis-à-vis sexuality. Furthermore, the importance of ensuring sexual lives are pleasurable and satisfying, and not only focused on negative consequences of sex has been emphasized by many agencies such as the World Association of Sexual Health as well as considering the positive impacts on health and well-being of safe and satisfying relationships. A further interpretation includes access to sex education, access to safe, effective, affordable and acceptable methods of birth control, as well as access to appropriate health care services, as the ability of women to go safely through pregnancy and childbirth could provide couples with the best chance of having a healthy infant.

Human sexual activity, human sexual practice or human sexual behaviour is the manner in which humans experience and express their sexuality. People engage in a variety of sexual acts, ranging from activities done alone (e.g., masturbation) to acts with another person (e.g., sexual intercourse, non-penetrative sex, oral sex, etc.) or persons (e.g., orgy) in varying patterns of frequency, for a wide variety of reasons. Sexual activity usually results in sexual arousal and physiological changes in the aroused person, some of which are pronounced while others are more subtle. Sexual activity may also include conduct and activities which are intended to arouse the sexual interest of another or enhance the sex life of another, such as strategies to find or attract partners (courtship and display behaviour), or personal interactions between individuals (for instance, foreplay or BDSM). Sexual activity may follow sexual arousal.

Human sexual activity has sociological, cognitive, emotional, behavioural and biological aspects. It involves personal bonding, sharing emotions, the physiology of the reproductive system, sex drive, sexual intercourse, and sexual behaviour in all its forms.

Sex differences in human physiology are distinctions of physiological characteristics associated with either male or female humans. These differences are caused by the effects of the different sex chromosome complement in males and females, and differential exposure to gonadal sex hormones during development. Sexual dimorphism is a term for the phenotypic difference between males and females of the same species.

The process of meiosis and fertilization (with rare exceptions) results in a zygote with either two X chromosomes (an XX female) or one X and one Y chromosome (an XY male) which then develops the typical female or male phenotype. Physiological sex differences include discrete features such as the respective male and female reproductive systems, as well as average differences between males and females including size and strength, bodily proportions, hair distribution, breast differentiation, voice pitch, and brain size and structure.