Question

Semen does not contain a. prostate fluid. b. urine. c. fructose. d. prostaglandins. e. Both b and d are correct.

Short answer

Urine is not a component of semen.

Step-by-step solution

Option a: Prostate fluid

Prostate fluid is indeed a component of semen, making up about 20-30% of its volume. It is released by the prostate gland, which plays a vital role in preparing sperm for fertilization. Therefore, option a is not the correct answer.

Option b: Urine

Urine is not a component of semen. Semen is composed of sperm and various other fluid secretions, primarily from the seminal vesicles, prostate gland, and bulbourethral glands. Urine is produced by the kidneys and excreted through the urethra, which is separate from the ducts that carry semen. Thus, option b could be the correct answer.

Option c: Fructose

Fructose is present in semen as it acts as an energy source for sperm cells. It mainly comes from the seminal vesicles, which contribute to about 60-70% of the volume of semen. Therefore, option c is not the correct answer.

Option d: Prostaglandins

Prostaglandins are hormone-like substances found in semen, playing various roles in the reproductive process, such as helping sperm to move more effectively through the female reproductive tract and promoting the survival of sperm outside the male body. They are primarily synthesized in the seminal vesicles. Thus, option d is not the correct answer.

Option e: Both b and d are correct

As we have already established that prostaglandins are indeed a component of semen, this option is not correct either. Based on our analysis, the correct answer is:

Answer

b. Urine

Key concepts

Semen Composition

Semen, a fluid expelled from the male reproductive system during ejaculation, plays a crucial role in reproduction. It is not just a simple fluid; rather, it comprises several components, each serving a particular function. Here’s a deeper dive into what makes up this vital fluid:

• Sperm Cells: The primary reproductive cells responsible for fertilization. Produced in the testes and stored in the epididymis, sperm accounts for about 2-5% of the total seminal volume.
• Seminal Vesicle Fluid: This constitutes the majority of semen's volume, about 60-70%. It is rich in fructose, which provides energy for sperm, and contains other substances that enhance sperm viability.
• Prostate Fluid: Contributing around 20-30% of the volume, this fluid is pivotal in the health and functionality of sperm, providing enzymes and other proteins necessary for sperm's journey in the female reproductive system.
• Bulbourethral (Cowper’s) Fluid: Though a smaller component, this pre-ejaculatory fluid helps in neutralizing acidity in the urethra for sperm survival.

Semen also contains substances like prostaglandins, important for enhancing the reproductive process. Understanding these components gives us insights into the intricate design and function of male reproductive biology.

Prostate Fluid

The prostate gland, an essential organ in the male reproductive system, secretes prostate fluid which becomes a part of semen. This fluid contributes significantly to the overall function and health of sperm:

• Role in Creating Alkaline Environment: Prostate fluid is slightly alkaline, which balances the acidic environment of the vagina, aiding in sperm survival.
• Enzymatic Activity: It contains enzymes like prostate-specific antigen (PSA) that help liquefy semen after ejaculation. This liquefaction is crucial as it allows sperm to swim freely towards the egg.

The prostate fluid's enzyme-rich composition not only supports the mobility and longevity of sperm but also prepares it for potential fertilization.

Fructose in Semen

Fructose, a sugar, plays a crucial role in providing energy to sperm. It is primarily secreted by the seminal vesicles, which are located near the junction of the vas deferens and urethra. Fructose is indispensable for sperm motility for several reasons:

• Energy Source: Sperm cells require energy to propel themselves through the female reproductive system. Fructose serves as a fuel to power the sperm’s tail (flagellum), allowing for effective movement.
• Metabolic Needs: Sperm are highly active cells with high metabolic requirements; fructose aids in meeting these needs by being a readily available source of ATP (adenosine triphosphate).

Without the presence of fructose, sperm would lack the essential energy needed for reaching and fertilizing the female egg, highlighting the key role that this carbohydrate plays in human reproduction.

Prostaglandins

Prostaglandins are hormone-like compounds present in semen and play a critical role in reproduction. Synthesized mainly in the seminal vesicles, these compounds have various functions:

• Facilitating Sperm Movement: Prostaglandins improve sperm motility by mediating muscle contractions within the female reproductive system, aiding sperm in their journey towards the egg.
• Enhancing Sperm Viability: They also contribute to maintaining sperm viability outside the male body by affecting the local immune response in the female reproductive tract.

The presence of prostaglandins illustrates the complex interplay of biological elements in human reproduction, encompassing the intricate processes required for successful fertilization.