Male Reproductive System Anatomy

• The male and female reproductive systems are responsible for sexual reproduction
• These systems produce gametes (sex cells) and hormones, and facilitate fertilization
• Significant differences exist in the anatomy of the male and female reproductive systems, reflecting their distinct roles in reproduction

Anatomy Of Male Reproductive System

• The primary organs of the male reproductive system include the testes, epididymis, vas deferens, seminal vesicles, prostate gland, bulbourethral glands, and penis
• These structures work together to produce, store, and transport sperm

Testes

• The testes (singular: testis) are the primary male reproductive organs, responsible for producing sperm and testosterone
• They are located within the scrotum, a sac-like structure that hangs outside the body, which helps regulate the temperature needed for sperm production, slightly lower than body temperature
• Each testis is an oval-shaped organ composed of tightly coiled tubes called seminiferous tubules, where sperm production (spermatogenesis) occurs
• Interstitial cells (Leydig cells) located between the seminiferous tubules produce testosterone, the primary male sex hormone
• The tunica albuginea is a fibrous capsule that covers the testis

Epididymis

• The epididymis is a coiled tube located on the posterior surface of each testis
• It is responsible for sperm maturation and storage
• Sperm spend about two to three weeks in the epididymis, where they mature and develop the ability to swim and fertilize an egg

Vas Deferens

• The vas deferens (ductus deferens) is a muscular tube that transports sperm from the epididymis to the ejaculatory duct
• It ascends from the scrotum, passes through the inguinal canal, and enters the pelvic cavity
• The vas deferens joins with the duct of the seminal vesicle to form the ejaculatory duct
• The spermatic cord contains the vas deferens along with blood vessels, nerves, and muscles that supply the testes

Seminal Vesicles

• The seminal vesicles are paired, pouch-like glands located on the posterior surface of the bladder
• They secrete a fluid that is rich in fructose, prostaglandins, and other substances that nourish and protect sperm
• This fluid contributes to the volume of semen

Prostate Gland

• The prostate gland is a single, walnut-sized gland located inferior to the bladder and surrounding the urethra
• It secretes a milky, alkaline fluid that helps neutralize the acidity of the vaginal tract, enhancing sperm motility and survival
• Prostatic fluid also contains enzymes that help liquefy semen after ejaculation

Bulbourethral Glands

• The bulbourethral glands (Cowper's glands) are two small glands located inferior to the prostate gland
• During sexual arousal, they secrete a clear, mucus-like fluid that lubricates the urethra and neutralizes any acidic urine that may be present

Penis

• The penis is the male organ for sexual intercourse
• It contains three cylindrical columns of erectile tissue: two corpora cavernosa and one corpus spongiosum
• The corpus spongiosum surrounds the urethra and forms the glans penis, the sensitive tip of the penis
• During sexual arousal, the erectile tissues fill with blood, causing the penis to become erect
• The prepuce (foreskin) is a retractable fold of skin that covers the glans penis; circumcision involves its surgical removal

Semen

• Semen is the fluid ejaculated from the male reproductive tract during orgasm
• It contains sperm and secretions from the seminal vesicles, prostate gland, and bulbourethral glands
• Semen provides a medium for sperm transport, nutrients, and protection from the acidic environment of the female reproductive tract

Anatomy Of Female Reproductive System

• The primary organs of the female reproductive system include the ovaries, fallopian tubes, uterus, vagina, and external genitalia (vulva)
• These structures support the production of eggs, facilitate fertilization, provide a site for fetal development, and enable childbirth

Ovaries

• The ovaries are the primary female reproductive organs, responsible for producing eggs (ova) and hormones (estrogen and progesterone)
• They are located in the pelvic cavity, one on each side of the uterus
• Each ovary is an almond-shaped organ containing follicles, which are sac-like structures that house developing oocytes (immature eggs)
• During the menstrual cycle, one follicle matures and releases an oocyte in a process called ovulation
• The corpus luteum forms from the ruptured follicle after ovulation and produces progesterone and estrogen

Fallopian Tubes

• The fallopian tubes (uterine tubes or oviducts) are paired tubes that extend from the ovaries to the uterus
• They transport the oocyte from the ovary to the uterus
• The fimbriae are finger-like projections at the distal end of each fallopian tube that sweep the released oocyte into the tube
• Fertilization typically occurs in the fallopian tube

Uterus

• The uterus is a pear-shaped organ located in the pelvic cavity, posterior to the bladder and anterior to the rectum
• It provides a site for implantation of the fertilized egg, fetal development, and labor
• The uterus consists of three layers: the endometrium (inner lining), myometrium (muscular layer), and perimetrium (outer layer)
• The endometrium undergoes cyclical changes during the menstrual cycle in preparation for implantation
• The myometrium contracts during labor to expel the fetus
• The cervix is the narrow lower portion of the uterus that connects to the vagina

Vagina

• The vagina is a muscular tube that extends from the cervix to the outside of the body
• It serves as the receptacle for the penis during sexual intercourse, the pathway for childbirth, and the route for menstrual flow
• The vaginal wall contains folds called rugae, which allow the vagina to expand during childbirth

External Genitalia (Vulva)

• The vulva includes the external female reproductive structures: the labia majora, labia minora, clitoris, and vestibule
• The labia majora are the outer folds of skin that enclose and protect the other external genitalia
• The labia minora are the inner folds of skin located within the labia majora
• The clitoris is a small, sensitive organ located at the anterior junction of the labia minora; it is homologous to the male penis
• The vestibule is the space between the labia minora that contains the openings of the urethra and vagina
• The greater vestibular glands (Bartholin's glands) are located on either side of the vaginal opening and secrete mucus to lubricate the vagina during sexual arousal

Mammary Glands

• The mammary glands are accessory organs of the female reproductive system that produce milk after childbirth
• They are located in the breasts and consist of lobules containing alveoli, which secrete milk
• Milk is transported through ducts to the nipple, where it is released during breastfeeding