The major contribution to the human seminal fluid is from:
**Core Concept**
The human seminal fluid is a complex mixture of secretions from various glands, which contribute to its composition and function. The major contributors to seminal fluid are the seminal vesicles, prostate gland, and bulbourethral glands.
**Why the Correct Answer is Right**
The seminal vesicles are a pair of tubular glands located behind the bladder, which secrete a significant portion of the seminal fluid. They produce a thick, alkaline fluid rich in fructose, which provides energy to the sperm and also has antibacterial properties. The secretions from the seminal vesicles make up approximately 60% of the total seminal fluid and play a crucial role in fertilization by creating a favorable environment for sperm motility and survival.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the seminal vesicles are not the only contributors to seminal fluid, but they are the major contributors. The other glands also play a significant role, but to a lesser extent.
**Option B:** This option is incorrect because the prostate gland primarily secretes a protein-rich fluid that contributes to the coagulation of semen, but it is not the major contributor to the total volume of seminal fluid.
**Option C:** This option is incorrect because the bulbourethral glands, also known as Cowper's glands, produce a clear, alkaline secretion that lubricates the urethra and helps to neutralize the acidity of the vagina, but they are not the major contributors to the seminal fluid.
**Clinical Pearl / High-Yield Fact**
The seminal vesicles are a common site for infections, such as seminal vesiculitis, which can cause symptoms like pelvic pain, fever, and infertility. It's essential to diagnose and treat these infections promptly to prevent long-term damage to fertility.
**Correct Answer: C. Bulbourethral glands**