Reproductive Anatomy D. Gamble SI 2010 All photos courtesy of Anthony’s Textbook of Anatomy & Physiology - 17th Edition

Male Reproductive System In conjunction with the female reproductive system, ensures the survival and propagation of the species. Consists of organs whose functions are to produce, transfer, and ultimately introduce sperm into the female reproductive tract. Secretes male sex hormones (androgens)

Male Reproductive Organs

Male reproductive organs… Are classified as: Essential Organs: - Gonads, produce gametes/sex cells (sperm) Accessory Organs: - genital ducts, glands, and supporting structures

Male Gonads >> Testes Small, flattened, oval shaped glands. 4-5 cm long, weigh about grams. Left testis hangs about 1cm lower in scrotal sac than the right. Suspended in scrotum. 2 main functions: - spermatogenesis - secretion of hormones

Spermatogenesis The production of sperm. Produced in the seminiferous tubules. (unraveled are about 2 feet long) Meiosis

Secretion of Hormones Main hormone is testosterone which is an androgen or masculinizing hormone. Testosterone serves the following functions: Promotes “maleness” and adult male sexual behavior. Regulates metabolism. The “anabolic” hormone - skeletal muscle building and bone growth.

Structure of Sperm

Reproductive (Genital) Ducts Epididymis - Single tightly-coiled tube measuring 20 feet in length! - Contributes to maturation of sperm (1 to 3 weeks). - Secretes a small amount of seminal fluid (semen). Vas Deferens - - Connects the epididymis to the ejaculatory duct. - Sperm remains in the vas deferens for varying amounts of time based on sexual activity. Ejaculatory Duct - - Short tubes connecting vas deferens to urethra. Urethra - - Serves as both a duct for reproductive AND urinary systems.

Accessory Reproductive Glands Seminal Vesicles - - Small pouches between the bladder/prostate and the rectum. - Secrete an alkaline fluid that makes up about 60% of semen volume. - Acidity? Sugar? Prostate Gland - - Doughnut shaped gland just below the bladder, encircles urethra. - Secretes watery, milky-looking fluid making up 30% of semen volume Cowper’s Glands - - Resemble peas in size and shape. - Secrete a small amount of alkaline fluid that helps counteract the acidity of the end of the urethra and the vagina. - Mucus secreted also helps lubricate the urethra to prevent friction damage to sperm during ejaculation.

Supporting Structures Scrotum - Skin covered pouch holding testes outside of the warm body. Penis - Comprised of Corpus Cavernosum, Corpus Spongiosum, and a covering of skin. End is the Glans Penis. Spermatic Chords - Cylindrical protein casings containing blood vessels, lymph vessels, nerves, and the vas deferens.

Female Reproductive System In conjunction with the male reproductive system, ensures the survival and propagation of the species. Female reproductive system also provides protection and nutrition to the developing offspring. Secretes female sex hormones (estrogens)

Female Reproductive Organs

Female reproductive organs… Are classified as: Essential Organs: - Gonads, produce gametes/sex cells (sperm) Testes in men, Ovaries in women. Accessory Organs: - uterine tubes, uterus, vagina, vulva, and mammary glands

Female Gonads >> Ovaries Produce the female gametes (ova). Secrete female hormones estrogen and progesterone. Each one located on one side of the uterus (about 3 gms).

Stages of Ovarian Follicle Development

The Uterus In a woman who has never been pregnant is pear-shaped, 3 inches long, 2 inches wide and about an inch thick. 2 main parts: the body and the cervix

Functions of the Uterus Part of the reproductive tract allowing sperm to ascend to the uterine (fallopian) tubes. After conception, developing offspring implants in inner wall (endometrium) and continues to develop during term of pregnancy. Creates labor “contractions”. If no conception or implantation, menstruation.

Normal and abnormal positions of the uterus.

Uterine Tubes Also called “Fallopian” tubes or oviducts. Extensions of the uterus that “loosely” communicate with the ovaries. Ovum carried through Fallopian tubes to uterus via cilia (tiny hair-like projections). Fertilization occurs here.

Vagina Tubular organ in front of rectum and behind the bladder & urethra. During sexual intercourse, the lining lubricates and stimulates the glans penis triggering ejaculation. Serves as a receptacle for semen. Lower portion of birth canal. Transports blood and tissues during menstruation.

VULVA = External Female Genitalia

The vulva is comprised of: Mons pubis Labia majora Labia minora Vestibular glands - Bartholin’s & Skene’s Vestibule Clitoris Urethral opening Vaginal orifice

The Female Breast

Female Breasts Lie over pectoral muscles. Development controlled by estrogen and progesterone. Breast size determined by amount of fat surrounding glandular tissue so function is NOT related to size. Main function is lactation for nourishment of newborn infants. Lactation is important for: - nutrients - antibodies - bonding