Discovering Human Sexuality 4e Chapter 3 Outline

The Male External Genitalia Are the Penis and Scrotum

The penis combines erotic, reproductive, and urinary functions
Box 3.1 Male Circumcision
Some disorders affect penile function
Box 3.2 How Big Should a Penis Be?
Box 3.3 Diphallia

Penile Erection Involves Nerves, Blood, and Chemistry

Erection is the filling of the penis with blood
Muscles are also involved in erection
Erections occur during sleep
The scrotum regulates the temperature of the testicles

The Testicles Produce Sperm and Sex Hormones

Other glands contribute secretions to the semen
Box 3.4 Declining Sperm Counts
Cancer and other disorders can affect the testicles
Other glands contribute secretions to the semen
What is semen?

Ejaculation Requires Coordination of Muscles and Glands

The testicles secrete sex hormones
Box 3.5 The Secret Life of Semen
The brain and pituitary gland regulate hormone levels
Box 3.6 Steroids and Sports

Nudity Is Culturally Regulated