Human sexuality refers to all the characteristics of an individual (social, personal, and emotional) that are manifest in his or her relationships with others and that reflect gender-genital orientation.

1. COMPONENTS OF SEXUAL SYSTEM
1. Biological sexuality—refers to chromosomes, hormones, primary and secondary sex characteristics, and anatomical structure.
2. Sexual identity—based on own feelings and perceptions of how well traits correspond with own feelings and concepts of maleness and femaleness; also includes gender identity.
3. Gender identity—a sense of masculinity and femininity shaped by biological, environmental, and intrapsychic forces, as well as cultural traditions and education.
4. Sex role behavior—includes components of both sexual identity and gender identity. Aim: sexual fulfillment through masturbation, heterosexual, or homosexual experiences. Selection of behavior is influenced by personal value system and sexual, gender, and biological identity. Gender identity and roles are learned and constantly reinforced by input and feedback regarding social expectations and demands Table 10-7. Sexual Behavior Throughout the Life Cycle .
2. CONCEPTS AND PRINCIPLES OF HUMAN SEXUAL RESPONSE
1. Human sexual response involves not only the genitals but the total body.
2. Factors in early postnatal and childhood periods influence gender identity, gender role, sex typing, and sexual responses in later life.
3. Cultural and personally subjective variables influence ways of sexual expression and perception of what is satisfying.
4. Healthy sexual expressions vary widely.
5. Requirements for human sexual response:
1. Intact central and peripheral nervous system to provide sensory perception, motor reaction.
2. Intact circulatory system to produce vasocongestive response.
3. Desirable and interested partner, if sex outlet involves mutuality.
4. Freedom from guilt, anxiety, misconceptions, and interfering conditioned responses.
5. Acceptable physical setting, usually private.