Discovering Human Sexuality 4e Chapter 2 Summary

  • A woman’s vulva (external genitalia) consists of the mons, clitoris, outer and inner labia (labia majora and minora), and vaginal opening.
  • A woman’s clitoris is a complex erectile organ, only a portion of which (the glans) is visible externally. Stimulation of the clitoris is a major source of sexual arousal in women.
  • The outer labia are two fat-padded folds of skin that form the sides of the vulva. The inner labia are two thinner, erotically sensitive folds of skin that enclose the vestibule—they fuse together at the front to form the hood of the clitoris. The vestibule is the space that encloses the entrance to the vagina and the opening of the urethra.
  • The female reproductive tract includes the vagina, cervix, uterus, and oviducts. At birth, the infant’s vagina is partially covered by a membrane (the hymen), which may be torn at first intercourse or earlier. The inner surface of the vagina is mildly acidic. Frequent douching can disturb the microbial balance, leading to a fungal infection and other problems. The walls of the vagina are more muscular and more sensitive in the outer portion than in the deeper portion. The G-spot is said to be a site of heightened erotic sensitivity on the front wall of the vagina, but its existence is debated.
  • The portion of the uterus that connects with the vagina is the cervix, which can be seen by inspection with a vaginal speculum or felt by inserting a finger into the back of the vagina. The main cause of cervical cancer is human papillomavirus (HPV), which is a sexually transmitted infection. Early detection of cancer by means of regular Pap tests has greatly reduced mortality from the disease.
  • The uterus serves as a pathway for sperm transport and also for implantation and development of the embryo. Medical conditions affecting the body of the uterus include fibroids, endometrial cancer, abnormal bleeding, uterine prolapse, and endometriosis. Hysterectomies (surgical removal of the uterus) may be done more frequently than necessary.
  • The oviducts bring an ovum and sperm together for fertilization, and they transport the resulting conceptus to the uterus. The ovaries are the female gonads; they produce ova and sex hormones. Ovulation is the release of an ovum from an ovary. The ovum enters the oviduct, where if sperm are present, it may be fertilized.
  • Steroid sex hormones fall into three classes—estrogens, androgens, and progestins—and are secreted by the gonads (ovaries and testes). Protein and peptide sex hormones include two gonadotropins—luteinizing hormone (LH) and follicle-stimulating hormone (FSH)—that are secreted by the pituitary gland, as well as gonadotropin-releasing hormone (GnRH), which is secreted by the hypothalamus.
  • Menstruation—the sloughing off of the uterine lining (endometrium)—is the outward manifestation of the menstrual cycle. A complete cycle usually lasts between 24 and 32 days.
  • The menstrual cycle has three phases: the menstrual phase, the preovulatory phase, and the postovulatory phase. The cycle is regulated by hormonal interactions between the hypothalamus, the pituitary gland, and the ovaries.
  • Women may use tampons, pads, or menstrual cups to absorb or block the menstrual flow. Some women experience pain during menstruation, or symptoms such as bloating and irritability during the days before menstruation, but many women do not think of their menstrual period as burdensome.
  • Women may experience painful periods (dysmenorrhea), a variety of physical and psychological symptoms prior to menstruation (premenstrual syndrome), absence of menstrual periods (amenorrhea), or excessively heavy menstrual bleeding. There are many causes for these conditions, but effective treatments are usually available.
  • Besides regulating the menstrual cycle, sex hormones have other functions: They are responsible for the anatomical changes in a girl’s body at puberty, they maintain bone density, and they affect brain organization and function—thus influencing a woman’s sexual feelings and behaviors in a fashion that varies with the phase of her menstrual cycle.
  • A woman’s secondary sexual characteristics include her breasts, which combine a sexual function (being a potential source of sexual arousal to her and her partner) with a reproductive function (lactation).
  • Breast cancer is the second most common cancer affecting women; risk factors include a family history of the disease, age, childlessness, alcohol use, and obesity. It can be detected early by clinical examination or mammography. Most breast lumps are not cancerous. Early-stage cancers can be treated without removal of the entire breast. Some breast cancer treatments, especially chemotherapy and mastectomy, may challenge women’s sexual self-image or sexual function, but most women who undergo breast cancer treatments are positive about their lives and sex lives.