It has been believed that the sex chromosomes of humans define the
sex (male or female) and their secondary sexual characteristics.
From childhood, we are controlled by our genetic makeup. It influences
the way we treat ourselves and others.
However, there are individuals who do not accept their innate sexual
characteristics and they tend to change their sexual organs through
medications and surgery.
This lesson helps us better understand ourselves through a discussion
on the development of our sexual characteristics and behavior.
3. Activity 1: defining beauty
Complete the sentences below.
1. For me, beauty means ____________________________________________________________________
2. A beautiful person is _______________________________________________________________________
3. I am beautiful because ____________________________________________________________________
4. List down names of people you know who are beautiful _______________________
4. Activity 2: sexual characteristics
Fill out the table below by listing the common secondary sexual male and female characteristics
Male secondary sexual characteristics Female secondary sexual characteristics
The gonads (reproductive glands that produce the gametes; testis or ovary) begin to form until
about the eighth week of embryonic development.
During the early stages of human development, the embryonic reproductive structures of males
and females are alike and are said to be in the indifferent stage.
When the primary reproductive structures are formed, development of the accessory structures and
external genitalia begins.
Any intervention with the normal pattern of sex hormone production in the embryo results in strange
abnormalities. As a result, pseudo hermaphrodites are formed who are individuals having
accessory reproductive structures that do not match their gonads.
Nowadays, many pseudo hermaphrodites undergo sex change operations to have their outer
selves (external genetalia) fit with their inner selves (gonads).
Puberty is the period of life, generally between the ages of 10 and 15 years old, when the
reproductive organs grow to their adult size and become functional under the influence of rising
levels of gonadal hormones ( testosterone in males and estrogen in females). After this time,
reproductive capability continues until old age in males and menopause in females.
The changes that occur during puberty is similar in sequence in all individuals but the age which
they occur differs among individuals. In males, as they reach the age of 13, puberty is characteristics
by the increase in the size of the reproductive organs followed by the appearance of hair in the pubic
area, axillary, and face. The reproductive organs continue to grow for two years until sexual
maturation marked by the presence of mature semen in the testes.
In females, the budding of their breasts usually occurring at the age of 11 signals their puberty stage.
Menarche is the first menstrual period of females which happens two years after the start of puberty.
Hormones play an important role in the regulation of ovulation and fertility of females.
10. Diseases Associated with the Reproductive
Infections are the most common problems associated with the reproductive system in adults.
Vaginal infections are more common in young and elderly women and in those whose
resistance to diseases is low.
The usual infection include those caused by Escherichia coli which spread through the
digestive tract; the sexually transmitted microorganism such as syphilis, gonorrhea, and
herpes virus and yeast (a type of fungus).
Vaginal infections that are left untreated may spread throughout the female reproductive tract
and may cause pelvic inflammatory disease and sterility.
Problems that involve painful or abnormal menses may also be due to infection or hormone
12. Diseases Associated with the Reproductive
In males, the most common inflammatory conditions are prostatitis, urethritis, and epididymitis, all
of which may follow sexual contacts in which sexually transmitted disease (STD) micro organism
are transmitted. Orchiditis, or inflammation of the testes, is rather uncommon but is serious
because it can cause sterility. Orchiditis most commonly follows mumps in an adult male.
Neoplasms are a major threat to reproductive organs. Tumors of breast and cervix are the most
common reproductive cancers in adult females, and prostate cancer (a common sequel to
prostatic hypertrophy) is a widespread problem in adult males.
Menopause- an event in which ovulation and menses stop entirely, ending childbearing ability.
There is no counterpart for menopause in males. Although aging men show a steady decline in
testosterone secretion, their reproductive capability seems unending. Healthy men are still able to
father offspring well into their 80’s and beyond.
13. Erogenous Zones
Erogenous zones refer to parts of the body that are primarily receptive
and increase sexual arousal when touch in a sexual manner.
Some of the commonly erogenous zones are the mouth, breast,
genitals, and anus.
Erogenous zones may vary from one person to another. Some people
may enjoy being touched in a certain area more than the other areas.
Other common areas of the body that can be aroused easily may
include the neck, thighs, abdomen, and feet.
14. Human Sexual Behavior
Human sexual behavior is defined as an activity-solitary, between
two persons, or in a group- that induces sexual arousal.
There are two major factors that determine human sexual
behavior: the inherited sexual response patterns that have evolved
as a means of ensuring reproduction and that become part of
each individual’s genetic inheritance, and the degree of restraint or
other types of influence exerted on the individual by society in the
expression of his sexuality.
15. Types of Behavior
The various types of human sexual behavior are usually classified according
to the gender and number of participants.
There is solitary behavior involving only one individual, and there is
sociosexual behavior involving more than one person.
Sociosexual behavior is generally divided into heterosexual behavior (male
with female) and homosexual behavior (male with male or female to female).
If three or more individuals are involved, it is, possible to have heterosexual
and homosexual activity simultaneously.
16. Solitary Behavior
Self-gratification means self-stimulation that leads to sexual arousal and generally, sexual
climax. Usually, most self-gratification takes place in private as a end in itself, but can also be
done in a sociosexual relationship.
Self-gratification, generally beginning at or before puberty, is very common among young
males, but becomes less frequent or is abandoned when sociosexual activity is available.
Consequently, self-gratification is most frequent among the unmarried. There are more males
who perform acts of self-gratification than females.
The challenge is to develop self-control in order to balance suppression and free expression.
Adolescents need to control their sexual response in order to prevent premarital sex and
17. Sociosexual Behavior
Heterosexual behavior is the greatest amount of sociosexual behavior that
occurs between only one male and one female. It usually begins in childhood
and may be motivated by curiosity, such as showing or examining genitalia.
Physical contact involving necking or petting is considered as an ingredients of
the learning process and eventually of courtship and the selection of a marriage
Petting differs from hugging, kissing, and generalized caresses of the clothed
body to practice involving stimulation of the genitals. Petting may be done as an
expression of affection and a source of pleasure, preliminary in coitus.
The insertion of the male reproductive structure into the female reproductive organ, is viewed
by society quite differently depending upon the marital status of the individuals.
Majority of human societies allow premarital coitus, at least under certain circumstances.
Post marital coitus ( by separated, divorced, or widowed person) is almost always ignored.
A behavior may be interpreted by society or the individual as erotic (capable of engendering
sexual response) depending on the context in which the behavior occurs. For instance, a kiss
may be interpreted as a gesture of expression or intimacy between couples while others may
interpret it as a form of respect or reverence.
19. Physiology of Human Sexual Response
sexual response follows a pattern of
sequential stages or phases when
sexual activity is continued.
20. 1. Excitement Phase
It is caused by increase in pulse and blood pressure; a sudden rise
in blood supply to the surface of the body resulting in increased
skin temperature, flushing, and swelling of all distensible body parts
(particularly noticeable in the male reproductive structure and
female breasts), more rapid breathing, the secretion of genital
fluids, vaginal expansion, and a general increase in muscle
tension. These symptoms of arousal eventually increase to a near
maximal physiological level that leads to the next stage.
21. 2. Plateau Phase
It is generally of brief duration. If stimulation is continued,
orgasm usually occurs.
22. 3. Sexual Climax
It is marked by a feeling of abrupt, intense pleasure, a rapid
increase in pulse rate and blood pressure, and spasms of the
pelvic muscles causing contractions of the female reproductive
organ and ejaculation by the male.
It is also characterized by involuntary vocalizations.
Sexual climax may last for a few seconds (normally not over ten),
after which the individual enters the resolution phase.
23. 4. Resolution Phase
It is the last stage that refers to the return to a normal or
subnormal physiologic state. Males and females are similar
in their response sequence. Whereas males return to
normal even if stimulation continues, but continued
stimulation can produce additional orgasms in females.
Females are physically capable of repeated orgasms
without the intervening “rest period” required by males.
When do we usually observe the changes listed above for males and females?
Were you able to experience the same changes? When?
How does the society shape the sexual behavior of an individual?
Can we really change our natural or innate sexual organ and sexual response?
Gonad- a reproductive gland
Gametes- a mature male or female germ cell
prostatitis- inflammation of prostate gland
urethritis- inflammation of urethra
epididymitis- inflammation of the epididymis