lecture recording on 13 March 2025 at 10.24.02 AM

Benign Prostatic Hyperplasia (BPH)

BPH involves the non-cancerous enlargement of the median lobe of the prostate gland, commonly affecting older men. The growth is predominantly attributed to the proliferation of glandular tissue, though it also includes hypertrophy of connective tissue, leading to a significant increase in prostate volume.

As the median lobe enlarges, it can compress the prostatic urethra, leading to narrowing of this passage. This anatomical change makes bladder emptying more difficult, resulting in a range of urinary symptoms including increased frequency, urgency, hesitancy, and a weak stream. Such restricted flow through a smaller space leads to increased bladder pressure and can potentially result in urinary retention.

Prostatic Plexus

The prostatic plexus surrounds the prostate gland and is constituted by an intricate network of nerves, arteries, veins, and lymphatics. It plays a crucial role in supporting prostate function, maintaining blood flow, and ensuring effective drainage. Key vessels contributing to this plexus include the middle rectal artery and the inferior vesical artery, which, despite lacking 'prostate' in their names, are vital for supplying blood to the prostate. Understanding the ligation of these vessels is crucial during surgical procedures such as prostatectomy, where preserving blood flow and nerve function is necessary to mitigate complications.

Innervation of the Male Reproductive System

The internal pudendal artery, a significant branch of the internal iliac artery, supplies the male reproductive tract, providing essential blood flow to areas such as the scrotum and penis. This artery has branches that include the dorsal artery and deep arteries, which specifically supply the erectile tissue. The pudendal nerve, originating from spinal segments S2-S4, innervates the perineum, providing vital somatic sensations and motor control necessary for sexual function. Mixed autonomic innervation to the reproductive system is facilitated by the inferior hypogastric plexus, which integrates sympathetic and parasympathetic fibers to coordinate functions such as ejaculation and erection.

Erectile Function

Erection is primarily facilitated through parasympathetic stimulation (often referred to as "pointing") via pelvic splanchnic nerves. Sympathetic nerves contribute to ejaculation functions, which can be conceptualized as "shooting." Reflexive erections can occur with an intact sacral spinal cord and are distinct from psychogenic erections, which necessitate brain stimulation and are influenced by psychological factors.

Venous Drainage and Metastatic Spread

Notably, prostatic plexus veins are unique in that they lack valves, allowing for bidirectional blood flow. This anatomical feature has significant implications for the spread of prostate cancer, which can metastasize via Batson's plexus into the vertebral and cranial regions, facilitated by this absence of venous valves. Imaging findings in prostate cancer often reveal metastasis in the pelvic bones and potentially the spinal column, with CT scans frequently highlighting these lesions and their locations.

Anatomy of the Prostate

The prostate gland is composed of both glandular and stromal tissues, categorized into several distinct zones:

• Central Zone: This zone is primarily involved in benign prostatic hyperplasia and may contribute to urinary symptoms in affected individuals.

• Transitional Zone: This area contains shorter submucosal glands and can also be involved in BPH.

• Peripheral Zone: This zone is the most common site for adenocarcinoma due to its glandular composition, underscoring the need for regular screening in at-risk populations. Changes in the prostate with aging are significant, leading to gland enlargement and various obstructive changes that can culminate in severe complications, including urinary difficulties and increased risk of infections.

Testicular Histology

In the male reproductive system, spermatogenesis occurs primarily within the seminiferous tubules, which are lined with germinal epithelium containing various stages of sperm development, including spermatogonia, spermatocytes, and spermatozoa. Supportive Sertoli cells within this environment nourish developing sperm and play a critical role in spermatogenesis. Leydig cells, located outside the seminiferous tubules, are responsible for testosterone production, a hormone crucial for male sexual function and overall health. Testicular architecture can be disrupted in conditions such as Klinefelter syndrome, impacting sperm development and hormonal regulation, leading to infertility and other health issues.

Ductal Anatomy and Function

The pathway for sperm transport begins in the seminiferous tubules, from where sperm pass to the rete testis, then to the efferent ductules, and ultimately into the epididymis. During this journey, sperm undergo maturation and storage, facilitated by the epididymis, which features a pseudostratified epithelium designed to support sperm viability. Additionally, seminal vesicles and the prostate contribute to the composition of seminal fluid, with the prostate gland functioning as an ivoromuscular glandular organ that produces a significant portion of the fluid that nourishes and helps transport sperm during ejaculation.

Clinical Implications

A profound understanding of prostate and testicular anatomy is indispensable for the diagnosis and management of urological disorders, encompassing various cancers and benign conditions. Knowledge of vascular supply and nervous innervation is crucial during surgical interventions to minimize complications, thus enhancing patient outcomes in conditions affecting the male reproductive system.