Male Reproductive System Flashcards
External Genital Organs
Penis
Scrotum
Internal Genital Organs
Testes Epididymites Ductus deferentes Seminal glands Ejaculatory ducts Prostate Bulbo-urethral (Cowper glands)
Penis
Long shaft, tip called the glans, foreskin called prepuce.
Contains spongy tissue that becomes turgid and erect when filled with blood.
Erectile Tissue
Corpus Spongiosum: covered by tunica albuginea, continuous with cavernosa and traversed by urethra.
Cylindrical and extends into glans penis.
Corpora Cavernosa: most of shaft, enveloped by tunica albuginea and contains most of blood in penis.
Penis - Ligaments
Suspensory ligament of penis: fundiform and triangular ligaments.
Scrotum
Protects testes and spermatic cords, keeps testes at 2-4°C lower than body temp.
Dartos muscle: wrinkles
Cremaster muscle: pulls scrotum closer to body for a higher temp.
Right and left components separated by a midline ridge: the raphe.
Penis - Blood Supply
Artery to the bulb Deep artery of the penis Dorsal artery of the penis Drained by: Mainly deep dorsal vein. Return blood to internal pudenal veins.
Penis - Innervation
Pudendal nerves
Perineal nerves
Posterior scrotal and dorsal nerves
Pelvic splanchnic nerves (S2 and S3)
Scrotum - Blood Supply
Superficial and deep external pudendal arteries.
Venous drainage: external pudendal veins.
Scrotum - Innervation
Iliolingual nerve (L1)
Scrotal branches of perineal nerve (S3)
Posterior femoral cutaneous nerve (S2)
Testes
Produce sperm and testosterone, lies within scrotum.
Left slightly lower than right.
Tightly coiled: seminiferous tubules with adjacent Leydig cells.
Sperm move from rete testis to epididymis.
Tunica albuginea covering testes.
Testes - Blood Supply
Testicular arteries.
Venous drainage: Pampiniform plexus
Testes - Innervation
Sympathetic nerves
Epididymis
Attached to posterolateral surface of the testis.
7 meters long tube, packed together by fibrous tissue.
Site of maturation and storage of spermatozoa.
Divided into 3 parts: head (directly connected to testicles), body and tail.
Epididymis - Blood Supply
Branches of testicular artery.
Venous return: pampiniform plexus
Epididymis - Innervation
Sympathetic nerves form the coeliac ganglion.
Ductus Deferens
Direct continuation of epididymis.
Thick muscular wall, minimal lumen.
Forms primary component of spermatic cord.
Terminates by joining the duct of the seminal gland to form ejaculatory duct.
Seminal Gland
5 cm long. Lies between fundus of bladder and rectum.
secrete a thick alkaline fluid with fructose and coagulating agent that mixes with sperm.
Joins ductus deferens to form ejaculary duct.
Seminal Glands - Blood Supply
Inferior vesicle and middle rectal arteries.
Venous drainage: inferior vesicle and middle rectal veins.
Ejaculatory Ducts
From union of ductus deferens and seminal duct.
Pierce the prostate and empty into urethra that runs through prostate gland.
Ejaculatory Ducts - Blood Supply
Superior and/or inferior vesical arteries.
Venous drainage: vena comitans.
Prostate
Largest accessory gland.
Secrete proteolytic enzymes into semen via prostatic ducts, break down clotting factors, allow semen to remain fluid.
Prostate - Size and Zones
Size of walnut, 2/3 glandular, 1/3 fibromuscular.
Central Zone: surrounds ejaculatory ducts, 25% of volume.
Transitional Zone: surrounds urethra, 5-10% of volume.
Peripheral Zone: posterior. Posterior. Main body of gland. 65%.
Fibromuscular Stroma: anterior.
Prostate - Blood Supply & Innervation
Branches of internal iliac artery.
Venous drainage: prostatic venous plexus drains into internal iliac veins.
Innervation: Pelvic splanchnic nerve
Bulbo-Urethral Glands (Cowper Glands)
Third accessory gland.
Empty directly into urethra.
Secrete lubricant on glans penis when penis is erect.
Bulbo-Urethral Glands (Cowper Glands) - Blood Supply
Bulbo-urethral artery
