Study Notes on Male Reproductive Function - Part Two

Instructor: Professor Anatol
Focus of the Lesson: Understanding the male reproductive system, specifically the accessory sex organs and seminal composition.
Importance of the Topic: Interest in the prostate gland, with over 20 years of research on the subject.

Define accessory sex organs and glands related to male reproductive function.
Explore the composition of semen and its role in supporting sperm transport from the testis to the female reproductive tract.

Accessory Glands: Include the prostate, seminal vesicles, bulbourethral glands, the epididymis, and vas deferens.
Key Points:
- Testis: Produces sperm and hormones.
- Epididymis: Storage and maturation of sperm.
- Vas Deferens: Tube for sperm transport.
- Prostate and Seminal Vesicles: Produce seminal fluid accompanying sperm.
- Bulbourethral Glands: Contribute to lubrication.

Structure: Series of coiled ducts adjacent to the testis, acting as a site for sperm maturation.
Function:
- Collects sperm from the testis which are initially immature.
- Completes final stages of sperm maturation over 20 days.
- Monitors and adjusts sperm composition and recycles damaged sperm.
- Consists of three parts:
- Head: Receives non-motile sperm.
- Body: Begins sperm motility.
- Tail: Stores mature sperm until ejaculation.
- Surrounded by smooth muscle for sperm expulsion during ejaculation.

Description: Long muscular tube transporting sperm from the epididymis to the urethra.
Notable for Surgical Procedure: Vasectomy - ligation that prevents sperm release during ejaculation, maintaining testicular function.
Structure: Simple passage facilitating sperm exit from the epididymis.

Location: Walnut-sized organ situated under the bladder, crucial for male reproductive function.
Role: Serves as an exocrine gland producing essential components of semen (30% of total volume).
Histology: Comprised of glandular ducts embedded in fibrous stroma.
Secretions: Includes a variety of substances critical for egg fertilization, such as:
- Proteolytic enzymes (aid in breaking down egg shell).
- Citrate (nutritional source).
- Prostatic specific antigen (PSA).
Hormone Regulation: Hormonal signaling via testosterone and DHT (dihydrotestosterone) influences secretions by activating androgen receptors, leading to transcriptional changes.
Health Issues:
- Prostatitis: Infection/inflammation of the prostate requiring antibiotics.
- BPH (Benign Prostatic Hyperplasia): Age-related enlargement causing urinary symptoms.
- Prostate Cancer: Common malignancy with significant research focus. May escape the prostate and metastasize.

Location: Situated above the prostate and contributing 60% of seminal fluid.
Function: Produces secretions and proteins that assist in sperm viability and motility. Key roles include:
- Coagulation of semen.
- Nutrient supply for sperm.
- Immune suppression in the female reproductive tract.
Hormonal Regulation: Similar to the prostate, receives similar endocrine signals. No known cancer occurrences in seminal vesicles.

Description: Two pea-shaped glands that provide secretion pre-ejaculation.
Function: Produce lubricating mucous fluid to neutralize and lubricate the urethra prior to ejaculation, contributing about 5% of semen composition.

Quantity at ejaculation: About 2 to 5 mL.
Sperm count: Can contain up to 150 million sperm per ejaculate.
Composition: A blend of secretions from seminal vesicles, prostate, and sperm, essential for reproduction.

Summary of Key Structures: The epididymis, vas deferens, prostate gland, seminal vesicles, and bulbourethral glands play crucial roles in sperm maturation, transport, and reproduction. All exocrine glands contribute specific secretions that are essential for successful fertilization during natural reproductive events.