Endosex - Briefing Human Sexuality

Introduction

Endosex refers to individuals born with physical features that differentiate them into male or female. For example, individuals with XY chromosomes are born with male genitalia and typical male characteristics. Conversely, individuals with XX chromosomes are born with female genitalia and female internal reproductive organs.

What Is Called the Sex of an Individual?

The sex of the patient is pure biology; it is the genetic makeup, the chromosomes, the expression of hormones, and the presence of reproductive organs. All these factors help decide the sex. Sex can be interpreted as homosexual, heterosexual, bisexual, or asexual.

• Heterosexual: Those who are physically and emotionally attracted to people of the opposite sex. They are usually said as "straight" heterosexual males attracted to heterosexual females and vice versa.

• Homosexual: These are groups of people attracted to people of the same sex. A female who is attracted to another female is called a lesbian, and a male who is attracted to another male is called gay.

• Bisexual: A group of people who are emotionally and physically attracted to both sex.

• Asexual: A group of people who are not interested in either sex but may be emotionally attached.

• LGBTQ: This describes the sexual orientation, whether lesbian, gay, bisexual, transgender, or questioning.

What Is Called Gender?

Gender is related to a person’s identity; it is how an individual behaves or does his responsibilities in society. Based on gender, classified into girl or boy, man or woman, and can be into another gender group.

What Are the Areas of Sexual Differentiation?

Sexual differentiation is done based on the following:

• Chromosomes and Genes: Chromosomes are the building blocks of our cells and contain genes. They are the fundamental unit of heredity and determine characteristics such as eye and hair color, height, and more. The number and type of chromosomes vary from species to species. Every individual has a set of chromosomes that determine their sexual characteristics. A chromosomal arrangement of XX describes it as female, and XY defines it as male. Apart from that, there are many other chromosomal patterns.

• People who have only one chromosome (XO).

• Those who have two X and one Y.

• People with an extra copy of Y (XYY).

• Chromosomal mosaicism, where some cells show one pattern and other cells show another chromosomal pattern.

• Some people have extra copies of genes that determine sexual characteristics, and some do not code for anything.

• Gonads: Another level of sex differentiation is based on the presence of gonads in an individual's body. Gonads are the body organs that produce gametes, eggs, or sperm. The male gonads that produce sperm are called testis, and the female gonads that produce eggs are called ovaries.

• External Genitalia/Anatomy: In people born with male or female chromosomal combinations and gonads, there can be variations in anatomic sexual features. Some of these variations can be subtle, but in others, significant problems require surgical intervention for normal functioning. Anatomic sexual differentiation is typically divided into two categories: gonadal and genital. Gonadal sexual differentiation refers to the development of the reproductive organs, whereas genital sexual differentiation refers to the development of all other external genitalia.

Male external genitalia includes the penis, scrotum, and testis. The female external genitalia includes the mons pubis, labia majora, labia minora, and clitoris. The area containing this genitalia is called the vulva.

What Is Called Intersex?

Intersex is a term used to refer to people born with sexual reproductive features that cannot be differentiated into male or female.

Intersex includes many different ways someone may fall on the gender binary. Intersex people have internal sex organs, making it difficult to categorize them into male or female. Such people have both ovarian and testicular tissues. Intersex people usually have chromosomal combinations other than XX or XY. Another variation can occur, where some people are born with external genitalia like that of males or females. Still, their internal organs or hormones show up with differences, and they are grouped as intersex. Being intersex means your body does not fit the standard definitions of masculinity or femininity.

What Are the Chances to Become Endosex and Intersex?

No accurate numbers predict the chances of becoming an endosex or intersex.

According to studies, only 1 in 200 live births becomes intersex, and the rest of the people by birth will be endosex. More chances for an individual to be born either as a male or female, called endosex.

Other chromosomal anomalies like Klinefelter's syndrome (XXY) or Turner's syndrome (XO) occur around 1in 1000 or 1 in 2500 live births. These two are the common intersex conditions with adequate data.

What Are the Terms Related to Endosex?

While talking about endosex, it is essential to know certain terms that are useful to understand.

• Difference or Disorder of Sexual Differentiation:

These are situations where the body is developed in a way that does not clearly differentiate into male or female. This condition can be termed an intersex condition.

• Glans:

The genital tubercle is an embryonic structure from which both clitoris and penis develop. In males, the glans develop into a part of the penis, depending on whether there is the presence of testosterone during the phase of prenatal development.

And in females, the glans develop into a part of the clitoris. These visible changes to anatomical structures are important for categorizing an individual as endosex or intersex during birth.

• Gonads:

Gonads are the structures that produce gametes and secrete most sex hormones. In males, the gonads are testis, and in females, the testis. Gonads produce major sex hormones -testosterone, estrogen, and progesterone. An individual is grouped into endosex or intersex, depending on the presence of gonads.

• Labioscrotal Swelling:

Labioscrotal swelling is a structure on its developmental pathway that becomes the labia or scrotum. This change occurs due to the presence of sex hormones.

• Sex Chromosomes:

Among the 23 pairs of chromosomes, one pair is sex chromosomes. For males, it is XY, and for females, it is XX. Therefore, any change in the combination of sex chromosomes can result in intersex individuals.

Conclusion

To know about developmental variations among humans, it is important to understand two terms- endosex and intersex. Endosex refers to individuals who can be categorized easily into males or females based on their physical characteristics. At the same time, all others with changes in basic physical features were grouped into Intersex. Biological sex is not always binary. Both endosex and intersex can have developmental variations. Both these groups of people can have a happy, functional life.