Human Reproduction Chapter 17.1 Page 548 - 554

Objectives Describe the path that sperm cells take through the male reproductive system Identify the organs of the female reproductive system and describe their functions Describe the major events of the female reproductive cycle.

Key Terms Fertilization Testis Scrotum Sperm cell Penis Urethra Seminal vesicles

Key Terms Semen Ejaculation Bulbourethral gland Uterus Ovary Fallopian tubes Vagina

Key Terms Follicle Ovulation Menstruation

The Male Reproductive System The testis produce Testosterone, a hormone that is crucial for the development of primary sex characteristics. The development of male reproductive organs before birth Testosterone is responsible for the development of secondary sex characteristics Adult males Larger skeletal muscles, hair on the face, a deep voice

The Male Reproductive System Testosterone signals Sperm cell production by the testis through an complex hormone system About 200 – 400 million per day, (one sperm cell can take 10 weeks from start to finish) They contain the genetic information, (1/2 the DNA) They have a special shape allowing them to move Semen is a mixture that contains sperm cells The prostate gland and seminal vesicles produce fluids that are added to the sperm in a tube called the vas deferens

The Male Reproductive System Sperm cells move from the testis to the penis The penis is composed of spongy tissue During arousal, the spongy tissue fills with blood, becoming erect, preparing a male for intercourse Sperm is deposited in the female reproductive system The urethra is a tube on the underside of the penis It can carry urine from the bladder or semen from the vas deferens Even before ejaculation watery discharge from the Bulbourethral gland may expel sperm into the female system Semen is expelled from the body by ejaculation Ejaculation is a reflexive response to nerve signals Contractions of the vas deferens expel semen

The Male Reproductive System Sperm cells carry the genetic material that determines the characteristics of offspring Males carry an X & Y chromosome and females carry an X & X chromosome Males determine the sex of the baby because only they carry the Y chromosome

The Female Reproductive System The center of the female reproductive system is the Uterus Contains and nourishes the developing baby inside the mother, (the womb) The Ovaries contain the reproductive cells of the female An undeveloped egg cell develops each month These egg cells are in place when the female is born, (each ovary contains about 400,000 cells), yet only about 400 may mature Unfertilized eggs are eliminated with the menstrual flow

The Menstrual Cycle Hormones needed for the cycle: FSH, (follicle stimulating hormone), begins the process of egg production Estrogen causes the production of LH, (luteinizing hormone), and matures the egg Progesterone is the body’s signal to prepare for pregnancy and stops LH and FSH production Brain hormones control the entire process

The Female Reproductive System As egg cells are released into the Fallopian Tubes from the ovary The egg moves down the Fallopian Tube to the Uterus Fertilization occurs in the Fallopian Tube by sperm Sperm cells released into the Vagina during the previous 72 hours may enter the egg The fused cells develop into a baby

Summary The male reproductive system consists primarily of two testes, two vas deferens, two seminal vesicles, the prostate gland, the bulbourethral gland, (or Cowper’s gland), and the penis The testes produce the male reproductive cells, (sperm cells), and the male hormone, (testosterone) Semen, the fluid that contains sperm cells, exits the male body by a reflex called ejaculation, (referred to in the path of sperm)

Summary The female reproductive system consists mainly of two ovaries, two fallopian tubes, the uterus, and the vagina The ovaries contain egg producing cells and produce the female hormones, progesterone and estrogen A single egg producing cell matures in one ovary, is expelled, (ovulated), every month