This medical illustration depicts the gross anatomy and histology of the human male reproductive system, specifically the testis and its associated ducts. The main diagram shows a sagittal-like section of the testis, highlighting internal lobules containing seminiferous tubules that converge at the rete testis. The epididymis is shown as a coiled ductal system attached to the posterior testis, divided into the caput (head), corpus (body), and cauda (tail), which then continues as the vas deferens. A magnified histological inset focuses on the interstitial space, showing Leydig cells clustered between cross-sections of seminiferous tubules. A second, high-magnification cross-section of a single seminiferous tubule illustrates the stages of spermatogenesis. Labeled structures include the peritubular cell layer (basal lamina), Sertoli cells for structural support, and germ cells in various stages of maturation: spermatogonia at the periphery, followed by spermatocytes I, and elongated spermatids positioned near the central lumen. This diagram serves as an educational tool for understanding the relationship between macroscopic anatomy and microscopic gametogenesis.

A 3D anatomical diagram illustrating the male and female reproductive systems side-by-side within stylized blue human silhouettes. On the left, the male anatomy includes the penis, a testis shown in cross-section within the scrotum, the epididymis, the vas deferens, the prostate gland, and the urinary bladder superiorly. On the right, the female anatomy depicts the uterus centrally, with the fallopian tubes extending laterally to the ovaries, and the vaginal canal positioned inferiorly. The visual highlights the pelvic location and relative spatial arrangement of primary and secondary sex organs. The image serves as an educational infographic for sexual health and reproductive anatomy, specifically in the context of public health strategies like the SAFE-S (Sexual behavior, Antibiotics, Facial cleanliness, Environmental improvement) strategy for controlling Chlamydia trachomatis and other sexually transmitted infections. The medical specialty is Urology and Gynecology, aimed at a general educational level.

This educational graphic combines an anatomical diagram of the male reproductive system with a histological micrograph, illustrating the mammalian epididymis. The primary diagram shows the testis with internal seminiferous tubules connecting via efferent ducts to the epididymis, which is divided into three distinct segments: the caput (head), corpus (body), and cauda (tail). The cauda eventually transitions into the vas deferens. An inset micrograph, labeled with a 30μm scale bar, provides a high-magnification cross-section of an epididymal tubule. This histological view identifies four key components: the central luminal sperm mass, the ciliated apical epithelia, the underlying columnar principal secretory epithelial cells, and an external smooth muscle cell layer responsible for peristalsis. The image serves as a conceptual framework for understanding post-testicular sperm maturation and identifying potential contraceptive targets, such as EPPIN, CRISP, P34H, and SFP2, or pharmacological agents like calcineurin-inhibitors and adrenoceptor antagonists that interfere with epididymal function.

This medical illustration depicts the pathophysiology and immune microenvironment of the human testis, focusing on the maintenance of immune privilege. The central diagram shows a cross-section of a seminiferous tubule featuring orange Sertoli cells (SCs) supporting developing spermatozoa. These are surrounded by purple immune cell clusters within the interstitial space. Exterior to the tubule, green Leydig cells are shown, noting their role in abrogating T cell-mediated orchitis via testosterone binding to androgen receptors. The diagram highlights the 'Relationship between Leydig cells, SCs, and T cells' in promoting the differentiation of tolerogenic dendritic cells (DCs) and T regulatory (Treg) cells. Accompanying text categorizes testicular immune cells: Macrophages (proinflammatory ED-1, anti-inflammatory ED-2, and NOS-producing types); Dendritic Cells (involved in Treg activation and autoimmunity in azoospermia); and T lymphocytes (Treg cells for immune privilege vs. Th and Th17 cells in autoimmune orchitis). The illustration serves as an educational tool for understanding the balance between immune tolerance and autoimmune pathology in male reproductive health.