1 MALE REPRODUCTIVE SYSTEM SCPA 602 Anatomical Basis for Pathological Study Updated: 20.09.2018 Lect. Nisamanee Charoenchon, PhD nisamanee.cha@mahidol.ac.th Department of Pathobiology, Mahidol University
2 Leading question What dominant types of cells in male reproductive system and their functions?
Components of the male reproductive system Midline structures are depicted in sagittal section; bilateral structures, including the testis, epididymis, ductus deferens, and seminal vesicle are shown intact.
Contents Histology of testes Histology of vas deferens Histology of seminal vesicle Histology of prostate gland Histology of the Bulbourethral gland
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6 External structures: 1. Penis include the penis, scrotum, and testicles. the root, which attaches to the wall of the abdomen; The glans of the penis also contains a number of sensitive nerve endings. the body, or shaft; and the glans, which is the cone-shaped part at the end of the penis. Circumcision The glans, also called the head of the penis, is covered with a loose layer of skin called foreskin -. Prepuce: The fold of skin that covers the head of the penis. Also known as the foreskin.
7 The body of the penis is cylindrical in shape - three circular shaped chambers. - special, sponge-like tissue (thousands of large spaces that fill with blood when the man is sexually aroused.) - The skin of the penis is loose and elastic to accommodate changes in penis size during an erection. - Semen, which contains sperm (reproductive cells), is expelled (ejaculated) through the end of the penis when the man reaches sexual climax (orgasm). When the penis is erect, the flow of urine is blocked from the urethra, allowing only semen to be ejaculated at orgasm.
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9 2. Scrotum These are two oval-shaped glands responsible for producing and storing sperm. loose pouch-like sac of skin that hangs behind and below the penis. contains the testicles (also called testes), as well as many nerves and blood vessels acts as a "climate control system" for the testes For normal sperm development, the testes must be at a temperature slightly cooler than body temperature. Special muscles in the wall of the scrotum allow it to contract and relax, moving the testicles closer to the body for warmth or farther away from the body to cool the temperature.
10 3. Testicles (testes): These are oval organs about the size of large olives lie in the scrotum, secured at either end by a structure called the spermatic cord. Most men have two testes. The testes are responsible for making testosterone, the primary male sex hormone, and for generating sperm. Within the testes are coiled masses of tubes called seminiferous tubules. These tubes are responsible for producing sperm cells.
Testis The adult testes are paired ovoid organs that lie within the scrotum 11
or Bulbourethral gland 12
Histology of testis Tunica albuginea- dense white fibrous capsule composed of dense irregular connective tissue, forming septa that divide each testis into series internal compartments called lobules.
14 The seminiferous tubules are highly convoluted; thus, the profiles that they present in the section are variable in appearance. 30x. Note the population of Leydig (interstitial) cells that occur in small clusters in
Schematic drawing of human seminiferous epithelium This drawing shows the relationship of the Sertoli cells to the spermatogenic cells. The seminiferous epithelium rests on a basal lamina, and a layer of peritubular cells surrounds the seminiferous tubule.
Spermatogenesis in seminiferous tubules
19 Leydig (interstitial) cells that produce testosterone to stimulate development of the indifferent primordium into a testis. an organ, structure, or tissue in the earliest stage of development. Interstitial cells of Leydig, located in the connective tissue surrounding the sperm-producing tubules of the testes, are responsible for the production and secretion of testosterone.
Seminiferous tubules Stratified germinal epithelium ( is also known as the wall of the seminiferous tubule within the testes ) Surrounded by a layer CT with fibroblast and an inner basement membrane (bm). Consist: Supporting (Sertoli cell) ( develop within the seminiferous cords produce another important hormonal substance, called Müllerian-inhibiting factor (MIF). )
Primary spermatocytes Spermatocytes Spermatids 21
Sertoli cells Supportive cells in the seminiferous tubules located among the spermatogenic cells do not replicate after puberty columnar cells with extensive apical and lateral processes surround the adjacent spermatogenic cells and occupy the spaces between them, also known as supporting, or sustentacular, cells. give structural organization to the tubules as they extend through the full thickness of the seminiferous epithelium physical support, protection and nutrition of the developing sperm (spermatids) Phagocytosis of cytoplasm developing sperm (spermatids) produce androgen-binding protein (ABP) ABPbinds testosterone in order to concentrate it for use in sperm maturation.
23 I. Germ cell : Sperm producing cells II. Sertoli cells : Norish sperm, produce hormone III. Interstitial (Leydig) cells In between tubules secrete testosterone Leydig cells (interstitial cells) - Large polygonal eosinophilic cells that contain lipid droplets Lipofuscin pigment - Frequently present in these cells as well as distinctive, rod shaped, cytoplasmic crystals, the crystals of Reinke Sertoli cells (sustentacular cells) - Tall columnar cells - Extend from the basal lamina to the lumen of seminiferous tubule - Interposed between the developing spermatogenic cells
Spermatogenesis Process where the spermatogenic cells in the seminiferous tubules divide, differentiate, and produce sperm. 3 phases Mitotic division of spermatogonia Meiotic division of spermatocytes, somatic chromosome no. spermatids Spermiogenesis morphological transformation spermatids sperm.
Testes produce both testosterone and sperm Leydig cells differentiate and secrete testosterone durin early fetal life. Secretion of testosterone is required during embryonic development, sexual maturation, and reproductive function.
26 LH and FSH are produced by the pituitary gland. LH binds to receptors on the interstitial cells (Leydig cells) and stimulate testosterone. FSH stimulates Sertoli cells to synthesize and release ABP (androgen-binding protein) into seminiferous tubules to stimulate spermatogenesis. concentration of testosterone essential for proper spermatogenesis.
Seminiferous tubule, straight tubules, rete testis & ductuli efferentes
Ductuli efferentes of the ductus epididymis
Ductuli efferentes of the ductus epididymis
Histology of vas deferens
Vas deferens A narrow and irregular lumen with longitudinal mucosal folds. Psuedostratified columnar epithelium with stereocilia. Thin lamina propria consists of compact colagen fibers and fie net work of elastic fibers. Thick muscularis 3 SM layers Inner longitudinal Middle circular Outer longitudinal Adventitia. Abundant of blood vessels
Ampulla of the vas deferens Terminal portion of the vas deferens enlarges into an ampulla Lumen of ampulla larger than vas deferens. Numerous irregular branching mucosal folds Deep glandular diverticula or crypts Simple columnar or cuboidal epithelium. Lamina propria 3 layers of SM Thin inner longitudinal Thick middle circular Thin outer longitudinal
Ampulla of the vas deferens
Accessory reproductive glands Seminal vesicles Yellowish viscous fluid high in fructose Energy source for sperm motility Produce most fluid found in semen Prostate gland Porduce thin, watery slightly acidic fluid The enzyme fibrinolysin liquefies the semen after ejaculation. Bulbourethral glands Produce clear, viscid, mucus-like secretion during erotic stimulation As lubricant for thr penile urethra.
Histology of seminal vesicle
Glandular epithelium of seminal vesicles normally varies Musosa arranged into convoluted folds lined by secretory pseudostratified columnar epithelium Smooth muscular layer and connective tissue stroma The lumen doesn t contain spermatozoa.
low pseudo stratified, low columnar or cuboidal.
Prostate gland & prostate urethra
Prostate gland Prostetic urethra Psuedostratified epithelium Glandular acini vary in size Lumina of acini normally wide and irregular Protrusion of epithelium-covered connective tissue folds Proteinaceous secretions sometimes prostatic concretions. Glandular epithelium simple-columnar or psuedot Fibromuscular stroma Characteristic feature of prostate gland SM bundles and CT fibers blend together in the stroma throughout the gland. ratified, cells lightly stain, some region squamous or cuboidal.
Histology of prostate gland
Histology of the Bulbourethral gland