Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System We truly are “fearfully and wonderfully made.” Almost any one of the body’s structures or functions might have inspired this statement, but of them all, perhaps the reproductive systems best deserves such praise. The achievement is the miracle of reproducing the human body; the goal is the survival of the human species. The Reproductive System 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System The male reproductive system consists of one group of organs and the female reproductive system consists of another group. These two systems differ in structure, but they share a common function – that of reproducing the human body. The Reproductive System 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System The male reproductive system consists of one group of organs and the female reproductive system consists of another group. These two systems differ in structure, but they share a common function – that of reproducing the human body. The Reproductive System 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System Germ cells (gametes) – the specialized sex cells required for reproduction. In the male – spermatozoa, or sperm. In the female – an ovum, or egg. Contains two type of organs: Primary (gonads) – 2 testes in the male and 2 ovaries in the female. Produce germ cells Make hormones Accessory organs – glands and ducts. 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System Accessory Organs of the Male Ducts Epididymis (2) Vas deferens (2) or Ductus deferens Ejaculatory duct (2) Urethra Supportive Sex Glands Seminal vesicle (2) Bulbourethral or Cowper’s Glands (2) Prostate Gland External Genitals Scrotum Penis 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System 6.13 Male Reproductive System

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System Accessory Organs of the Female Ducts Fallopian Tubes (2) Uterus Vagina Accessory Sex Glands Bartholin’s Glands Breasts External Genitals Vulva 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System 6.13 Female Reproductive System

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System Male Reproductive System External Genitalia Penis Scrotum 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System Male Reproductive System External Genitalia Penis – male organ of sexual intercourse Corpus Spongiosum Corpus Carvenosum Sexual Stimulation Under the stimulus of sexual emotion, blood floods the spaces in the erectile tissue of the corpora, distending them enough to produce erection of the penis. The climax is characterized by the ejaculation of semen from the penis. 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System 6.13 Male Reproductive System (cont.)

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System Male Reproductive System External Genitalia Scrotum Contains: – Testis Sperm production Production of testosterone – Epididymis – Lower part of the Vas Deferens – Beginning of the Spermatic Cord 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System 6.13 Scrotal Sac

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System Sperm Motility Sperm cells are contained in seminiferous tubules. At the top part of each testis is the epididymis. Sperm develop to maturity and become able to move. Enter a narrow tube called the vas deferens. Travel to the seminal vesicles. Secrete fluid to help the sperm move. Pass through the ejaculatory duct leading to the prostate gland and the urethra. The prostate gland secretes a fluid that helps the sperm move and contracts its muscle tissue to help ejaculate the sperm. 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System Sperm Motility Below the prostate are the two bulbourethral glands, or Cowper's glands - secretes a fluid that lubricates the inside of the urethra. The urethra passes through the penis (end of the penis – glans penis) to the outside of the body. 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System Fertilization The spermatozoon is a microscopic cell, much smaller than an ovum. It has a tail that propels the sperm forward. During ejaculation, hundreds of millions of sperm are released. Usually only one sperm can fertilize a single ovum. In some cases, two or more ova are fertilized at a single time, resulting in multiple births. Identical twins are the result of the splitting of one ovum after a single sperm has fertilized it. Fraternal twins are the result of two sperm fertilizing two ova. 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System Female Reproductive System The ovaries release an egg as part of the ovarian cycle. A fertilized egg is transported via one of the fallopian tubes to the uterus Develops into an embryo and then into a fetus. The baby is born through the vagina or surgically through the abdomen in a Caesarean delivery. 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System Female Reproductive System The ovaries release an egg as part of the ovarian cycle. A fertilized egg is transported via one of the fallopian tubes to the uterus Develops into an embryo and then into a fetus. The baby is born through the vagina or surgically through the abdomen in a Caesarean delivery. 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System Female Reproductive System The ovaries Lie on either side of the uterus Within the pelvic cavity Release one mature ovum during each monthly cycle - ovulation. 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System 6.13 Female Reproductive System (cont.)

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System 6.13 Female Reproductive System (cont.)

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System Female Reproductive System (cont.) The Female Reproductive System (cont.) Estrogen and progesterone. Other hormones, which help in childbirth and milk production. 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System What are germ cells? 6.13

Copyright © The McGraw-Hill Companies, Inc.Chapter 6 Human Structure and Function The Reproductive System Specialized sex cells What are germ cells? 6.13