The Male Reproductive System: Organs, Structure, Function

The male reproductive system produces, stores, and transports sperm for fertilisation. It has a pair of testes, present in the scrotum, which are responsible for the production of sperm and the male hormone, testosterone. The epididymis helps in the storage and maturation of sperm, which then travel through the vas deferens during ejaculation.

This Story also Contains

1. What is the Male Reproductive System?
2. Organs of the Male Reproductive System
3. Functions of the Male Reproductive System
4. Hormonal Control of the Male Reproductive System
5. MCQs on the Male Reproductive System
6. Recommended video on The Male Reproductive System

Accessory organs such as the seminal vesicles, prostate gland, and bulbourethral glands secrete the seminal fluid and other fluids that help in the nourishment and maturation of the sperm. The male gamete, sperm, along with the seminal fluid, make up the semen. The penis is the male copulatory organ and helos in the transfer of the semen into the female reproductive tract. The hormonal regulation by the hypothalamus and pituitary gland also influences sperm production. The Male Reproductive System is an important topic in the biology subject.

What is the Male Reproductive System?

The male reproductive system consists of a complex system of organs and structures whose function is to produce sperm, the male sex hormone testosterone, and facilitate reproduction. Knowledge of this anatomy and physiology is very important to understand mutual reproductive health challenges.

The male reproductive system includes both internal and external organs that play a role in the production of sperm and their transportation. The male reproductive system contains three working parts that involve testes, accessory glands, and the penis.

Organs of the Male Reproductive System

The male reproductive system includes the testes, epididymis, vas deferens, seminal vesicles, prostate gland, and penis. These organs work together to produce, mature, store, and transport sperm.

• Testes: These are a pair of small oval-shaped organs that are found in the scrotum. They are responsible for producing the spermatozoa and the male sex hormone called testosterone.

• Scrotum: A bag of skin that holds the testes outside of the abdominal cavity. It provides the required temperature to the testes so they can maintain the ideal temperature for sperm production.

• Epididymis: It is a long, coiled tube behind each testis. Its functions are to act as a storage of sperm and where the sperm mature.

• Vas Deferens: A smooth, muscle-lined tube that contracts to assist in the conducting of mature sperm from the epididymis to the urethra.

• Seminal Vesicles: Two glands that produce the greater part of the fluid containing nutrients for sperm and form a part of semen.

• Prostate Gland: A gland that secretes fluids, energising and protecting sperm; this secretion is also added to semen.

• Bulbourethral Glands (Cowper's Glands): Ducts of these glands discharge a pre-ejaculatory fluid that lubricates the urethra and acts as a neutraliser of acidity.

• Penis: This is the male's external sex organ. It conveys sperm, after sexual intercourse, into the female reproductive tract. It discharges sperm into the female reproductive tract. It comprises erectile tissues and fills with blood to acquire an erection.

• Urethra: A small tube transporting urine from the bladder out of the body and the semen from the reproductive system.

Functions of the Male Reproductive System

Its primary functions are sperm production (spermatogenesis), delivery of sperm to the female reproductive tract, and secretion of male sex hormones, especially testosterone.

• Sperm Production: The male reproductive system's primary function is to produce sperm through the testes.

• Hormone Production: Testes are also responsible for producing a secondary male sexual characteristic known as testosterone, which regulates reproductive functions and maintains reproductive tissues.

• Production of Semen: Accessory glands produce seminal fluid that nourishes and protects sperm, allowing them to travel during copulation.

• Ejaculation: The release of sperm during sexual arousal, in which sperm leaves the testicles, passes through the epididymis and vas deferens, gets mixed with seminal fluid, and is then expelled out of the urethra.

Hormonal Control of the Male Reproductive System

The hormonal control of the male reproductive system is regulated by hormones such as GnRH, FSH, LH, and testosterone, which control spermatogenesis, testicular development, and secondary sexual characteristics.

• Gonadotropin-Releasing Hormone (GnRH) is released from the hypothalamus and acts on the anterior pituitary to release FSH and LH.

• Follicle-Stimulating Hormone (FSH) acts on the Sertoli cells in the testes and controls spermatogenesis.

• Luteinizing Hormone (LH) stimulates the Leydig cells to release testosterone.

• Testosterone regulates the development of the secondary sexual characteristics of the male. It also provides feedback inhibition to control the pituitary hormone levels.

• Inhibin is secreted by the Sertoli cells and inhibits the production of FSH to regulate sperm production.

MCQs on the Male Reproductive System

Q1. Shrinking and relaxation of scrotum respectively is due to _____?

Option 1: Increased Temperate & decreased temperature

Option 2: Decreased temperature & Increased temperature

Option 3: Increased Temperate & Increased temperature

Option 4: Decreased temperature & Decreased temperature

Correct answer: 2) Decreased temperature & Increased temperature.

Explanation:

The scrotum maintains the temperature of the testes 2- 3 degrees Celsius below the body temperature.

When the temperature of the testes falls the scrotum shrinks bringing the scrotum close to the body to attain the desired temperature.

When the temperature rises the scrotum is relaxed and the testes come down at a distance from the body.

Hence, the correct answer is option 2)Decreased temperature & Increased temperature.

Q2. Seminal plasma in humans is rich in:

Option 1: Fructose and calcium have no enzymes.

Option 2: Glucose and certain enzymes but have no calcium.

Option 3: Fructose and certain enzymes but poor in calcium.

Option 4: Fructose, calcium and certain enzymes.

Correct answer: 4) Fructose, calcium and certain enzymes.

Explanation:

Components of Seminal Plasma:

1. Water: This acts as the fundamental solvent, facilitating sperm transportation.

2. Fructose:
Source: Seminal vesicles.
Role: Supplies energy essential for sperm motility.

3. Prostaglandins:
Source: Seminal vesicles.
Role: Induces contractions in the female reproductive tract's smooth muscles, thus promoting sperm movement.

4. Proteins and Enzymes:
Examples: Fibrinogen, and fibrinolysin.
Role: Semen coagulation and subsequent liquefaction to free sperm.

5. Alkaline Compounds:
Source: Prostate gland.
Role: Counteracts the acidic female reproductive environment.

6. Zinc, Citric Acid, and Calcium:
Source: Prostate gland.
Role: Ensures sperm chromatin stability and overall sperm health.

Hence, the correct answer is option 4) Fructose, calcium and certain enzymes.

Q3. The function of Sertoli cells is/are

Option 1: To provide nutrition to the germ cells

Option 2: Secret inhibin hormone

Option 3: Phagocytosis of cytoplasm of spermatids

Option 4: All of these

Correct answer: 4) All of these

Explanation:

Testes has three types of cells:

1. Spermatogonia that form cells

2. Leydig cells secrete testosterone

3. Sertoli cells are nurse cells that nourish developing s[erms

Other functions of Sertoli cells are

• Release Androgen binding protein

• Secrete inhibin hormone

• Bring about phagocytosis of the cytoplasm of spermatids to convert them into sperms

Hence, the correct answer is option 4) All of these

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