Female Reproductive System

• The reproductive system consists of organs working together for sexual reproduction.
• Fluids, hormones, and pheromones are non-living accessories to the reproductive system.
• Sexes of differentiated species often have very different reproductive systems.
• These differences include contributing organs, hormones and physiological factors.

Female Reproductive System

• The female reproductive system has two main functions: to produce egg cells, and to protect and nourish the offspring until birth.
• The female reproductive system includes the ovaries, the fallopian tubes, the uterus, the vagina, and the vulva.
• The ovaries produce egg cells, called ova or oocytes.
• During ovulation, an ovum is released from an ovary.
• The ovum travels through the fallopian tube to the uterus.
• If the ovum is fertilized by sperm, it implants in the wall of the uterus and develops into a fetus.
• The vagina is a muscular canal that connects the uterus to the outside of the body.
• The vulva is the external female genitalia.

Male reproductive system

• The male reproductive system has one main function: to produce and deliver sperm to the female reproductive system.
• The male reproductive system includes the testes, the epididymis, the vas deferens, the seminal vesicles, the prostate gland, and the penis.
• The testes produce sperm.
• Sperm mature and are stored in the epididymis.
• During ejaculation, sperm travel through the vas deferens to the seminal vesicles.
• The seminal vesicles add fluid to the sperm to form semen.
• The semen travels through the prostate gland and then out of the body through the penis.
• The penis is the male organ used for sexual intercourse.

Hormones

• Hormones play an important role in the reproductive system.
• In females, the ovaries produce estrogen and progesterone.
• Estrogen is responsible for the development of female secondary sexual characteristics, such as breasts and wider hips.
• Progesterone prepares the uterus for pregnancy and helps maintain pregnancy.
• In males, the testes produce testosterone.
• Testosterone is responsible for the development of male secondary sexual characteristics, such as facial hair and a deeper voice.
• Testosterone also plays a role in sperm production.

Sexual Reproduction

• Sexual reproduction is a type of reproduction that involves the fusion of two gametes.
• Gametes are sex cells that contain half the number of chromosomes as other cells in the body.
• In humans, the gametes are the egg and sperm.
• When an egg and sperm fuse, they form a zygote.
• The zygote contains the full number of chromosomes.
• The zygote develops into a new individual.

The Reproductive System and Aging

• The reproductive system changes with age.
• In females, the ovaries stop producing eggs at menopause.
• This leads to a decrease in estrogen and progesterone levels.
• This can cause a number of symptoms, such as hot flashes, vaginal dryness, and bone loss.
• In males, testosterone levels decrease with age.
• This can lead to a decrease in muscle mass, bone density, and sexual function.

Disorders of the Reproductive System

• There are a number of disorders that can affect the reproductive system.
• These disorders can affect both males and females.
• Some common disorders of the female reproductive system include:
  • Endometriosis
  • Uterine fibroids
  • Ovarian cysts
  • Pelvic inflammatory disease (PID)
  • Cervical cancer
  • Breast cancer
• Some common disorders of the male reproductive system include:
  • Prostate cancer
  • Testicular cancer
  • Erectile dysfunction
  • Infertility

Ovaries

• The ovaries are the female gonads.
• They are located in the pelvic cavity, one on each side of the uterus.
• Each ovary is about 2.5 to 5 cm long, 1.5 to 3 cm wide, and 0.6 to 1.5 cm thick.
• The ovaries are responsible for producing eggs and hormones.

Egg Production

• Oogenesis is the process of egg production in females.
• It involves the differentiation of oogonia into mature oocytes.
• Oogenesis begins before birth, when oogonia in the ovaries of a female fetus begin meiosis.
• These cells are arrested in prophase I and remain dormant until puberty.
• At puberty, some of these primary oocytes will continue through meiosis I to form a secondary oocyte and a polar body.
• The secondary oocyte is ovulated.
• If fertilized by a sperm, the secondary oocyte will complete meiosis II to form an ovum and another polar body.
• The ovum is the mature female gamete.

Hormone Production

• The ovaries produce two main hormones: estrogen and progesterone.
• Estrogen is responsible for the development of female secondary sexual characteristics, such as breasts and wider hips.
• Estrogen also plays a role in the menstrual cycle and pregnancy.
• Progesterone prepares the uterus for pregnancy and helps maintain pregnancy.

Fallopian Tubes

• The fallopian tubes, also known as uterine tubes or salpinges, are two tubes that connect the ovaries to the uterus.
• Each fallopian tube is about 10 to 13 cm long.
• The fallopian tubes are responsible for transporting eggs from the ovaries to the uterus.
• Fertilization of the egg by sperm typically occurs in the fallopian tubes.

Uterus

• The uterus, also known as the womb, is a pear-shaped organ located in the pelvic cavity.
• The uterus is about 7.5 cm long, 5 cm wide, and 2.5 cm thick in a woman who has never been pregnant.
• The uterus is larger in women who have been pregnant.
• The uterus is responsible for nourishing and protecting the developing fetus during pregnancy.

Structure of the Uterus

• The uterus has three layers:
  • The endometrium is the inner lining of the uterus.
  • It is shed during menstruation.
  • The myometrium is the muscular layer of the uterus.
  • It contracts during labor.
  • The perimetrium is the outer layer of the uterus.

Vagina

• The vagina is a muscular canal that connects the uterus to the outside of the body.
• The vagina is about 8 to 10 cm long.
• The vagina is responsible for receiving sperm during sexual intercourse.
• The vagina is also the birth canal through which a baby passes during childbirth.

Vulva

• The vulva is the external female genitalia.
• The vulva includes the labia majora, labia minora, clitoris, and vaginal opening.
• The labia majora are the outer folds of skin that protect the other external genitalia.
• The labia minora are the inner folds of skin that surround the clitoris and vaginal opening.
• The clitoris is a small, sensitive organ that is responsible for sexual pleasure.

Testes

• The testes are the male gonads.
• They are located in the scrotum, which is a sac of skin that hangs outside the body.
• Each testis is about 4 to 5 cm long, 2.5 cm wide, and 3 cm thick.
• The testes are responsible for producing sperm and testosterone.

Sperm Production

• Spermatogenesis is the process of sperm production in males.
• It involves the differentiation of spermatogonia into mature spermatozoa.
• Spermatogenesis begins at puberty and continues throughout life.
• Spermatogonia are located in the seminiferous tubules of the testes.
• Spermatogonia divide by mitosis to produce more spermatogonia and primary spermatocytes.
• Primary spermatocytes undergo meiosis I to form secondary spermatocytes.
• Secondary spermatocytes undergo meiosis II to form spermatids.
• Spermatids mature into spermatozoa.

Hormone Production

• The testes produce testosterone.
• Testosterone is responsible for the development of male secondary sexual characteristics, such as facial hair and a deeper voice.
• Testosterone also plays a role in sperm production.

Epididymis

• The epididymis is a coiled tube located on the back of each testis.
• The epididymis is about 6 meters long.
• The epididymis is responsible for storing and maturing sperm.

Vas Deferens

• The vas deferens is a tube that carries sperm from the epididymis to the seminal vesicles.
• The vas deferens is about 30 to 45 cm long.
• The vas deferens travels through the spermatic cord, which also contains blood vessels, nerves, and the cremaster muscle.

Seminal Vesicles

• The seminal vesicles are two pouch-like glands located behind the bladder.
• The seminal vesicles produce a fluid that is added to sperm to form semen.
• This fluid is rich in fructose, which provides energy for the sperm.

Prostate Gland

• The prostate gland is a walnut-sized gland located below the bladder.
• The prostate gland produces a fluid that is added to sperm to form semen.
• This fluid contains enzymes that help to liquefy the semen.

Penis

• The penis is the male organ used for sexual intercourse.
• The penis contains three cylinders of erectile tissue:
  • The corpora cavernosa
  • The corpus spongiosum
• The corpus spongiosum surrounds the urethra, which is the tube that carries urine and semen out of the body.
• During sexual arousal, the erectile tissue fills with blood, causing the penis to become erect.