Male Reproductive System Anatomy

• The male reproductive system anatomy includes testes, epididymis, vas deferens, accessory genital glands, penis, and scrotum.
• Male reproductive organs produce, mature, and store spermatozoa, and deliver spermatozoa in semen into the female reproductive tract.
• The urethra functions as a passageway for urine excretion.

Male Genital Organs

• Male genital organs have internal and external components.
• Internal genital organs: testis, epididymis, ductus (vas) deferens, seminal vesicle, ejaculatory ducts, prostate gland, bulbourethral glands, and urethra.
• External genital organs: penis and scrotum.

Internal Genital Organs

• The testis is the primary organ which produces sperm, secretes hormones, and seminal fluid.
• Accessory ducts receive, store, and transport sperm (epididymis, ductus deferens, ejaculatory duct).
• Accessory genital glands include the seminal vesicle, prostate gland, and bulbourethral (Cowper's) gland.

Testis

• The testis is the male gonadal organ that lies in the scrotum.
• Testis’ function is the production of spermatozoa and secretion of testosterone.
• Testis dimensions: Oval shape, 4cm length, 2.5cm breadth.
• The testis has upper and lower poles, anterior and posterior borders, and medial and lateral surfaces.
• Fibrous septa divides the interior of the testis into around 250-300 lobules.
• Each testis is composed of seminiferous tubules, which is its functional unit.
• Coverings of the testis: tunica vaginalis, tunica albuginea (capsule), and tunica vasculosa.
• Tunica vaginalis is a double membrane forming the outer covering of the testes and originates as a down growth of the abdominal and pelvic peritoneum.
• Tunica albuginea is a fibrous covering beneath the tunica vaginalis. Ingrowths form septa, dividing the glandular structure of the testes into lobules.
• Tunica vasculosa consists of a network of capillaries supported by delicate connective tissue.
• During fetal development, the testis develops near a kidney.
• The testis descends through the inguinal canal and enters the scrotum around the 7th gestational month.

Epididymis

• The epididymis of the male reproductive system is comma-shaped and located within the scrotum.
• The epididymis is a coiled tube, 6m in length and lies posterolateral to the testis
• Head, body, and tail are the epididymis’ three parts.
• The epididymis stores and matures of spermatozoa and also has a function of fluid absorption.

Ductus (vas) Deferens

• There are two ductus deferens.
• They are surrounded by smooth muscle
• The ductus deferens begins in the tail of the epididymis.
• The ductus deferens ascends in the spermatic cord.
• Transports sperms from the epididymis to the ejaculatory duct.

Ejaculatory Ducts

• Ejaculatory ducts are formed by the connection of the seminal vesicles duct and ductus deferens duct.
• Ejaculatory ducts pass through the prostate and open into the prostatic urethra.

Urethra

• The urethra has the following parts: prostatic urethra, membranous urethra, and spongy (penile) urethra.
• There are two urethral sphincters.
• The internal sphincter is a ring of smooth muscle at the neck of the bladder above the prostate gland.
• The external sphincter is a ring of skeletal muscle surrounding the membranous part.

Seminal Vesicle

• Accessory gland tubes that are 2 inches long.
• Seminal Vesicles lie extraperitoneally on each side at the base of the urinary bladder.
• The seminal vesicle’s lower end joins the ductus deferens to form the ejaculatory duct.
• The gland is immediately lateral to the ductus deferens at the posterior of the urinary bladder.
• The duct of the seminal vesicle joins the ductus deferens to form the ejaculatory duct.
• The seminal vesicles secrete seminal fluid (60%), containing fructose to nourish sperm and aid movement.

Prostate Gland

• It is a pyramidal shaped fibro-muscular gland
• Gland lies immediately inferior to the urinary bladder
• Gland surrounds the prostatic urethra
• The prostate gland secretes a thin, milky, alkaline fluid to enhance sperm motility.

Bulbourethral Glands (Cowper's)

• A pair of small-sized glands located near the base of the penis; a short duct from each gland enters the penile urethra.
• The gland secretes an alkaline mucus-like fluid that neutralizes vaginal acidity and provides lubrication during intercourse.
• They're located near the base of the penis, below the prostate gland and secrete about 1% of seminal fluid to clean the urethra from the urine.

External Male Genital Organs

• The penis is a male copulatory organ that excretes urine and semen composed of the root, body, and glans.
• The penis root anchors the penis in the perineum, the body is the externally visible, moveable portion of the organ, and the glans is the tip/top portion of the penis.
• The Glans penis has many nerve endings, making it very sensitive.
• The internal structures of the penis consist of three erectile tissue.
• Two corpora cavernosa are located posteriorly and one corpus spongiosum is located anteriorly.

Scrotum

• The scrotum is a pendulous sac of skin located behind the penis.
• The scrotum provides an environment that is 3° cooler than body temperature.
• Contents of scrotum: testis, epididymis, and the lower part of the spermatic cord.
• The scrotum is divided by right and left by a median ridge or raphe.
• The left scrotum hangs lower than the right because the left spermatic cord is longer.
• Layers of the scrotum: skin, dartos muscle (smooth), external spermatic fascia, cremasteric muscle and fascia (skeletal), and internal spermatic fascia.
• The spermatic cord refers to a collection of vessels, nerves, and ducts that run to and from the testes (surrounded by fascia, forming a cord-like structure).
• Structure of the spermatic cord: vas deferens testicular artery, testicular vein (Pampiniform plexus), testicular lymph vessels, autonomic nerves, processus vaginalis, cremasteric artery, artery of the vas deferens, and the genital branch of the genitofemoral nerve.

Overview of the male reproductive system anatomy, including internal and external genital organs. Covers testes, epididymis, vas deferens, accessory genital glands, penis, and scrotum. Describes the functions of sperm production, storage, and delivery.