LESSON 9
THE HUMAN REPRODUCTIVE (GENITAL) SYSTEM
Section I. INTRODUCTION
9-1. DEFINITION
The human reproduction system is a collection of organs for the production of
offspring. Thus, succeeding generations are provided for the continuation of the
species.
9-2. TWO DISTINCT SEXES
In humans there are two distinctly separate sexes, male and female. The
presence of different anatomical forms of the two sexes is called sexual dimorphism.
DI = two
MORPH = body form
SEXUAL = by virtue of sex
The contribution of hereditary materials by two parents increases the chances for
improved genetic recombinations.
9-3. SEX HORMONES
Sex hormones are body chemicals associated with sex and sexual development.
They belong to a chemical group called steroids. Sex hormones are formed primarily in
two types of organs: the gonads and the adrenal cortex. (The adrenal cortex is the
outer layer of the adrenal gland, which rests upon each kidney). The sex hormones of
the female are called estrogens and progesterone. The sex hormones of the male are
called androgens.
9-4. MAJOR ORGAN SUBGROUPS
In both males and females, the organs of the reproductive system can be
grouped according to function. These subgroups are the primary sex organs (gonads),
the secondary sex organs, and the secondary sexual characteristics.
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