Both the epithelium of the vagina and the cervical glands of the uterus help prevent the invasion and spread of vaginal pathogens. Explain how each of these mechanisms works.

Grant, a sexually active adolescent, visited his doctor complaining of a red, painless swelling on his penis. He has no penile discharge or pain on urination. An account of his recent sexual behavior was requested and recorded.

a. What do you think Grant's problem is?

b. What is the causative agent of this disorder?

c. How is the condition treated, and what may happen if it isn't treated?

Oogenesis in the female results in one functional gamete—the egg, or ovum. What other cells are produced? What is the significance of this rather wasteful type of gamete production—that is, production of a single functional gamete instead of four, as seen in males?

Gina Marciano, a 44-year-old mother of eight children, visited her physician complaining of a 'bearing down' sensation in her pelvis, low backache, and urinary incontinence. A vaginal examination showed that the external os of her cervix was just inside the vaginal orifice and her perineum exhibited large keloids (masses of scar tissue). What do you think Gina's problem is and what caused it? (Be anatomically specific.)

Define menarche. What does it indicate?

In menstruation, the functional layer is shed from the endometrium. Explain the hormonal and physical factors responsible for this shedding. (Hint: See Figure.)

Trace the pathway of a sperm from the male testes to the uterine tube of a female.