tHE MALE REPRODUCTIVE SYSTEMThe

Outline: Male Reproductive System

• Location and Components

  • Located in the pelvis region

  • Includes a pair of testes, accessory ducts, glands, and external genitalia

• Testes

  • Situated in the scrotum outside the abdominal cavity

  • Scrotum maintains low temperature for spermatogenesis

  • Each testis is oval-shaped, 4-5 cm in length, and 2-3 cm in width

  • Covered by a dense covering

  • Contains about 250 testicular lobules

• Testicular Lobules

  • Each lobule contains 1-3 highly coiled seminiferous tubules

  • Spermatogenesis occurs in the seminiferous tubules

• Accessory Ducts and Glands

  • Include epididymis, vas deferens, ejaculatory duct, and urethra

  • Glands like seminal vesicles, prostate gland, and bulbourethral glands contribute to semen production

• External Genitalia

  • Consists of penis and scrotum

  • Penis is involved in copulation and urine excretion

  • Scrotum houses the testes and helps regulate their temperature

• Function

  • Production of sperm cells (spermatogenesis)

  • Secretion of male sex hormones (e.g., testosterone)

  • Delivery of sperm to the female reproductive system during sexual intercourse

Outline: Male Reproductive System

• Seminiferous Tubules

  • Lined by male germ cells (spermatogonia) and Sertoli cells

  • Male germ cells undergo meiotic divisions for sperm formation

  • Sertoli cells provide nutrition to germ cells

• Interstitial Spaces

  • Located outside seminiferous tubules

  • Contain Leydig cells (interstitial cells)

  • Leydig cells synthesize and secrete androgens

• Male Sex Accessory Ducts

  • Include rete testis, vasa efferentia, epididymis, and vas deferens

  • Seminiferous tubules open into vasa efferentia through rete testis

  • Vasa efferentia lead to epididymis, then to vas deferens ascending to abdomen

  • Vas deferens loops over urinary bladder, receives duct from seminal vesicle

  • Opens into urethra as ejaculatory duct

• Transport of Sperm

  • Ducts store and transport sperm from testis to outside through urethra

  • Urethra originates from urinary bladder, extends through penis

  • External opening of urethra is urethral meatus

Outline for Male Reproductive System Diagrams

• Figure 2.1(a): Diagrammatic Sectional View of Male Pelvis Showing Reproductive System

  • Male external genitalia

    • Penis

      • Special tissue for erection

      • Glans penis

        • Covered by foreskin

  • Male accessory glands

    • Seminal vesicles

    • Prostate

    • Bulbourethral glands

      Sure! Here's a mnemonic for remembering the male accessory glands:

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      S - Seminal vesicles

      P - Prostate

      B - Bulbourethral glands

  • Seminal plasma

    • Constituents

      • Fructose

      • Calcium

      • Enzymes

• Figure 2.1(b): Diagrammatic View of Male Reproductive System

  • Testis details

    • Inner details shown

  • Penis

    • External genitalia

  • Male accessory glands

    • Seminal vesicles

    • Prostate

    • Bulbourethral glands

  • Bulbourethral glands' secretions

    • Lubrication of the penis

tHE MALE REPRODUCTIVE SYSTEM

The male reproductive system is located in the pelvis region(Figure 2.1a). It includes a pair of testes alongwithaccessory ducts, glands and the external genitalia. he testes are situated outside theabdominal cavity within a pouchcalled scrotum. The scrotum helpsin maintaining the low temperatureof the testes (2–2.5o C lower thanthe normal internal bodytemperature) necessary forspermatogenesis. In adults, eachtestis is oval in shape, with a lengthof about 4 to 5 cm and a width ofabout 2 to 3 cm. The testis iscovered by a dense covering. Eachtestis has about 250 compartmentscalled testicular lobules(Figure 2.1b).Each lobule contains one tothree highly coiled seminiferoustubules in which sperms areproduced. Each seminiferous tubuleis lined on its inside by two typesof cells called male germ cells(spermatogonia) and Sertoli cells(Figure 2.2 ). The male germ cellsundergo meiotic divisions finallyleading to sperm formation, whileSertoli cells provide nutrition to thegerm cells. The regions outside theseminiferous tubules calledinterstitial spaces, contain smallblood vessels and interstitial cellsor Leydig cells (Figure 2.2). Leydigcells synthesise and secretetesticular hormones calledandrogens. Other immunologicallycompetent cells are also present.The male sex accessory ducts include rete testis, vasa efferentia,epididymis and vas deferens (Figure 2.1b). The seminiferous tubules ofthe testis open into the vasa efferentia through rete testis. The vasa efferentialeave the testis and open into epididymis located along the posterior surfaceof each testis. The epididymis leads to vas deferens that ascends to theabdomen and loops over the urinary bladder. It receives a duct from seminalvesicle and opens into urethra as the ejaculatory duct (Figure 2.1a). Theseducts store and transport the sperms from the testis to the outside throughurethra. The urethra originates from the urinary bladder and extendsthrough the penis to its external opening called urethral meatus The penis is the male external genitalia (Figure 2.1a, b). It is made upof special tissue that helps in erection of the penis to facilitate insemination.The enlarged end of penis called the glans penis is covered by a loose foldof skin called foreskin.The male accessory glands (Figure 2.1a, b) include paired seminalvesicles, a prostate and paired bulbourethral glands. Secretions of theseglands constitute the seminal plasma which is rich in fructose, calciumand certain enzymes. The secretions of bulbourethral glands also helpsin the lubrication of the penis.