The testes manufacture testosterone, the hormone that stimulates the development of a male’s secondary sex characteristics and sperm, the male reproductive cells. 

Thanks to medical advances, HIV has evolved into a chronic disease instead of a fatal one. 

Derived from the Greek word for seizure, epilepsy is the term used to refer to a variety of neurological disorders characterized by sudden attacks (seizures) of violent muscle contractions and unconsciousness. 

Cancer is the leading cause of death worldwide; 8.7 million die each year from the disease. 

The term intimacy—the open, trusting, and sharing of close, confidential thoughts and feelings—comes from the Latin word for “within.” Intimacy doesn’t happen at first sight, or in a day, or a week, or a number of weeks. 

Anyone who engages in penile-vaginal intercourse must be willing to accept the consequences of this activity, including the possibility of conceiving a child, or take action to avoid an unintended pregnancy. 

Couples interested in adoption can work with either public agencies or private counselors who contact obstetricians directly. Or they can contact organizations that arrange adoptions of children in need from other countries.  

Of all our involvements with others, sexual intimacy, or physical closeness, can be the most rewarding. 

In about 60 to 75 percent of all pregnancies, there is increased risk of some problem, such as failure of the fetus to grow normally. 

 Gender identity, an individual’s internal sense of being male, female, both, or neither, is a product of both innate and external influences and can shift over time.