Download Careers360 App
Primary and Secondary Sex Organs: Description, Characteristics

Primary and Secondary Sex Organs: Description, Characteristics

Edited By Irshad Anwar | Updated on Jul 03, 2025 02:23 PM IST

Gamete production in both males and females is the function of the primary sex organs. They release hormones which help to regulate the formation of gametes and control the secondary sexual characteristics as well. The secondary sex organs have no role in gamete production, but help in the transportation, fertilisation, and nourishment of the gametes and embryos.

This Story also Contains
  1. What are Primary Sex Organs?
  2. Role of Primary Sex Organs
  3. What are Secondary Sex Organs?
  4. Role of Secondary Sex Organs
  5. MCQs on Primary and Secondary Sex Organs
  6. Recommended video on Primary and Secondary Sex Organs
Primary and Secondary Sex Organs: Description, Characteristics
Primary and Secondary Sex Organs: Description, Characteristics

The maturation and sperm delivery into the female reproductive tract are the functions of the primary and secondary sex organs. In females, the secondary sex organs receive the sperm and provide a site for fertilisation and implantation. Jointly, these organs help in the proper functioning of the reproductive system. Primary and Secondary Sex Organs are important topics in the biology subject.

What are Primary Sex Organs?

The primary sex organs, or gonads, are associated with the production of gametes and sex hormones. The testes are the male primary sex organs, and the ovaries are the female primary sex organs.

Role of Primary Sex Organs

Primary sex organs (testes in males and ovaries in females) are responsible for producing gametes—sperm and ova—and secreting sex hormones like testosterone and estrogen.

Male Primary Sex Organs

Testes: The testes produce sperm and the hormone testosterone. They are located outside of the abdomen within the scrotum, which provides the proper temperature for spermatogenesis.

Female Primary Sex Organs

Ovaries: Ovaries are the organs wherein the eggs (ovum) and the female sex hormones, namely estrogen and progesterone, are produced. The process of formation of an ovum is known as oogenesis. They are paired organs, meaning that there are two, and are located in the pelvic cavity on each side of the uterus.

What are Secondary Sex Organs?

The secondary sex organs give rise to secondary sex characteristics and support sexual intercourse. They support the primary sex organs in performing their role.

Role of Secondary Sex Organs

Secondary sex organs (like the penis, vas deferens, uterus, and vagina) support the transport, fertilization, and nurturing of gametes and embryos, facilitating successful reproduction.

Epididymis

This is a coiled tube at the back of each testis responsible for storing and maturing sperm. It also connects the sperm from the testes to the vas deferens.

Vas Deferens:

This is a muscular tube that carries mature sperm from the epididymis to the urethra. Aside from this, it also carries along with it the seminal fluid coming from the seminal vesicles.

Seminal Vesicles

The seminal vesicles are sac-like glands which produce a fructose-rich nutrient fluid, a type of food for the sperm to gain motility.

Prostate Gland

The prostate gland secretes fluids that nourish and protect the sperm. The fluids form part of the semen. All the male accessory ducts and male accessory glands work in harmony to support sperm transport and fertilisation.

Urethra

The urethra is a tube through which the urinary bladder discharges urine, and the male reproductive system discharges semen to the outside of the body via the penis.

Penis

The penis is the male external reproductive organ that conveys the sperm into the female reproductive tract during intercourse. It has erectile tissue, allowing it to engorge with blood, and therefore be erected.

Secondary Sex Organs Of The Female

Fallopian Tubes

The fallopian tubes take the egg from the ovary into the uterus. Fertilisation usually occurs within the fallopian tube.

Uterus

The uterus is a muscular organ in which a fertilised egg implants and grows into a fetus. Its lining is called the endometrium, and it thickens up anticipating pregnancy. The fallopian tube and the uterus are the sites of fertilisation in humans and implantation of the ovum, with the development of the fertilised egg, respectively.

Cervix

The cervix is located at the lower end of the uterus and it opens into the vagina. This part of the uterus acts as a one-way passage because, despite allowing sperm to pass into the uterus, it does not allow menstrual blood to come out of it.

Vagina

The vagina is a muscular tube connecting the cervix to the external genitalia. It acts as a birth canal, and it is also the receptacle for the penis during sexual intercourse.

External Genitalia

The female external genitalia, or vulva, include the clitoris, labiae, and opening of the vagina. While they trigger sexual arousal, they also protect the internal organs.

MCQs on Primary and Secondary Sex Organs

Q1. Which of the following is a secondary sex organs in male?

Option 1: Rete testes

Option 2: Seminiferous tubules

Option 3: Seminal vesicles

Option 4: Both a & c

Correct answer: (4) both a & c

Explanation:

Secondary sex organs in males consist of accessory ducts and accessory glands.

The male sex accessory ducts include rete testis, vasa efferentia, epididymis and vas deferens. rete testes and epididymis are secondary/ accessory sex organs. The male accessory glands include paired seminal vesicles, prostate and paired bulbourethral glands. Seminiferous tubules are functional units of testes that merge into a network of tiny tubules called rete testes. Rete testes are secondary sex organs in males. Seminal vesicles are accessory glands that are secondary sex organs in males. Seminiferous tubules are functional units of testes that we primary sex organs in males.

Hence, the correct option is (4) both a & c

Q2. Among the given pairs of homologous structures, which one is mismatched?

Option 1: Clitoris and penis

Option 2: Vagina and prostatic utricle

Option 3: Scrotum and labia majora

Option 4: Fallopian tube and prostate gland

Correct answer: 4) Fallopian tube and prostate gland

Explanation:

The fallopian tube and prostate gland are not homologous structures because they serve different functions in the reproductive systems of males and females. The fallopian tube is part of the female reproductive system involved in transporting eggs from the ovary to the uterus. On the other hand, the prostate gland is found in males and plays a role in producing and secreting seminal fluid. While both structures are involved in reproduction, they have distinct origins and functions, making them mismatched as homologous structures.

Hence, the correct answer is option 4) Fallopian tube and prostate gland

Q3. Which of the following are accessory glands of the male reproductive system?

Option 1: Bulbourethral glands

Option 2: Prostate gland

Option 3: Seminal vesicles

Option 4: All of the above

Correct answer: 4) All of the above

Explanation:

  • Secondary sex organs in males consist of accessory ducts and accessory glands.

  • The male sex accessory ducts include rete testis, vasa efferentia, epididymis and vas deferens. rete testes and epididymis are secondary/ accessory sex organs.

  • The male accessory glands include paired seminal vesicles, prostate and paired bulbourethral glands.

Hence, the correct answer is Option 4) All of the above

Recommended video on Primary and Secondary Sex Organs



Frequently Asked Questions (FAQs)

1. Which are the primary sex organs in the male and female?

 The primary sex organs in the male are the testes and in the female, the ovaries.

2. What is the function of the penis?

 During intercourse, the penis ejaculates sperm into the female reproductive tract.

3. What are the accessory glands of the male reproductive system?

 The accessory glands, including the prostate gland, seminal vesicles, and bulbourethral glands, produce the fluids that nourish and transport the sperm.

4. What is the reproductive purpose of the uterus?

 A fertilised egg implants and grows into a fetus within the uterus during pregnancy.

5. What is the purpose of the fallopian tube?

 The fallopian tubes conduct the ova from the ovaries to the uterus, and within them is the site for fertilisation.

6. How does the female reproductive system prepare for potential pregnancy each month?

The female reproductive system undergoes a monthly cycle (menstrual cycle) in preparation for potential pregnancy. This involves the maturation of an egg in the ovary, thickening of the uterine lining, and hormonal changes. If fertilization doesn't occur, the uterine lining is shed during menstruation. This cyclical process ensures that the reproductive system is regularly prepared for the possibility of conception and embryo implantation.

7. How do the ovaries function as both endocrine and exocrine glands?

Ovaries serve dual functions as both endocrine and exocrine glands. As endocrine glands, they produce hormones like estrogen and progesterone, which regulate the menstrual cycle and support pregnancy. As exocrine glands, they produce and release eggs (ova) during ovulation. This dual role makes the ovaries central to female reproductive function, influencing both hormonal balance and the potential for fertilization.

8. What is the role of the cervix in female reproduction, and how does it change during the menstrual cycle?

The cervix is the lower part of the uterus that connects to the vagina. It plays several important roles in reproduction:

9. What is the significance of the hypothalamic-pituitary-gonadal axis in reproductive function?

The hypothalamic-pituitary-gonadal (HPG) axis is a complex system that regulates reproductive function. The hypothalamus releases gonadotropin-releasing hormone (GnRH), which stimulates the pituitary to produce follicle-stimulating hormone (FSH) and luteinizing hormone (LH). These hormones then act on the gonads (testes or ovaries) to stimulate sex hormone production and gametogenesis. This feedback loop is crucial for maintaining reproductive health and regulating the menstrual cycle in females.

10. How do the structures of male and female reproductive systems reflect their different functions?

The male and female reproductive systems have evolved distinct structures to serve their specific functions. The male system is designed to produce and deliver sperm, with structures like the testes for sperm production, epididymis for sperm maturation, and penis for sperm delivery. The female system is adapted for egg production, fertilization, and fetal development, featuring ovaries for egg production, fallopian tubes for fertilization, and a uterus for embryo implantation and fetal growth.

11. What is the significance of the blood-testis barrier in male reproduction?

The blood-testis barrier is a physical barrier formed by tight junctions between Sertoli cells in the testes. It separates the seminiferous tubules, where sperm develop, from the blood supply. This barrier is crucial for male fertility as it creates a protected environment for sperm development, shielding developing sperm cells from the immune system and potentially harmful substances in the bloodstream.

12. What is the process of spermatogenesis, and how long does it take?

Spermatogenesis is the process of sperm production in the testes. Key points include:

13. What is the role of the epididymis in sperm maturation?

The epididymis is a highly coiled tube located on the surface of each testis. Its primary functions in sperm maturation include:

14. What are primary sex organs and why are they called "primary"?

Primary sex organs, also known as gonads, are the testes in males and ovaries in females. They are called "primary" because they are essential for reproduction, producing gametes (sperm or eggs) and sex hormones. These organs are present from birth and play a central role in sexual development and reproduction.

15. How do the primary sex organs contribute to sexual differentiation during fetal development?

During fetal development, the presence or absence of the SRY gene on the Y chromosome determines whether the undifferentiated gonads will develop into testes or ovaries. If testes develop, they produce testosterone, which drives the development of male internal and external genitalia. Without testosterone, the fetus develops female genitalia. This process, known as sexual differentiation, sets the stage for further development of sex organs and characteristics.

16. How do secondary sex organs differ from primary sex organs?

Secondary sex organs, unlike primary sex organs, are not directly involved in gamete production. Instead, they support the reproductive process by facilitating the transfer of gametes, providing a suitable environment for fertilization, or nurturing the developing embryo. Examples include the penis, vagina, uterus, and breasts. They develop during puberty under the influence of sex hormones produced by the primary sex organs.

17. How do the mammary glands prepare for and produce milk during pregnancy and after childbirth?

Mammary gland development and milk production involve several stages:

18. How do sexually transmitted infections (STIs) affect the reproductive organs?

Sexually transmitted infections can impact reproductive organs in various ways:

19. What is the role of the hypothalamus in regulating reproductive function?

The hypothalamus plays a crucial role in regulating reproduction by:

20. How does the female reproductive system change during menopause?

Menopause marks the end of a woman's reproductive years and involves several changes:

21. Can you explain the concept of sexual dimorphism in relation to sex organs?

Sexual dimorphism refers to the physical differences between males and females of the same species. In humans, this is evident in both primary and secondary sex organs. For example, males have testes and a penis, while females have ovaries, a uterus, and breasts. These differences are crucial for reproductive functions and are influenced by sex hormones during development.

22. What is the role of accessory glands in the male reproductive system?

Accessory glands in the male reproductive system, including the seminal vesicles, prostate gland, and bulbourethral glands, produce fluids that combine with sperm to form semen. These fluids provide nutrients for sperm, help neutralize the acidic environment of the vagina, and facilitate sperm motility. The prostate gland, for example, produces an alkaline fluid that helps neutralize the acidic environment of the urethra and vagina, protecting the sperm.

23. What is the function of the scrotum, and why is its location important?

The scrotum is a sac of skin and muscle that holds the testes outside the body cavity. Its primary functions are:

24. What role do hormones play in the development of primary and secondary sex organs?

Hormones are crucial in the development of both primary and secondary sex organs. During fetal development, hormones like testosterone and estrogen guide the formation of primary sex organs. At puberty, these hormones surge again, triggering the development of secondary sex characteristics. For instance, testosterone promotes the growth of facial hair and deepening of voice in males, while estrogen stimulates breast development in females.

25. How does the structure of the penis enable its function in reproduction?

The penis is structured to perform its reproductive function through several key features:

26. How do the fallopian tubes facilitate fertilization?

Fallopian tubes, also called oviducts, play a crucial role in fertilization by:

27. How does the uterus adapt to support pregnancy?

The uterus undergoes significant changes to support pregnancy:

28. What is the function of the placenta, and how does it develop?

The placenta is a temporary organ that develops during pregnancy, serving as an interface between maternal and fetal circulation. Its functions include:

29. How do hormonal contraceptives work to prevent pregnancy?

Hormonal contraceptives prevent pregnancy through several mechanisms:

30. What is the function of the corpus luteum, and how does it change if pregnancy occurs?

The corpus luteum is a temporary endocrine structure formed from the remnants of the ovarian follicle after ovulation. Its functions include:

Articles

Back to top