The Reproductive System

The Basics Reproduction is the only life function that is NOT necessary for the individual to survive BUT it is necessary for the survival of the SPECIES Reproduction is the only life function that is NOT necessary for the individual to survive BUT it is necessary for the survival of the SPECIES Types: Types: Asexual – one parent, offspring are identical to one another Asexual – one parent, offspring are identical to one another Examples: bacteria, hydra, plants Examples: bacteria, hydra, plants Sexual – two parents, offspring are different from one another Sexual – two parents, offspring are different from one another Examples: humans, pandas, turtles, plants Examples: humans, pandas, turtles, plants

Male Reproductive System

The Testes and Scrotum Testes – male gonad Produce sperm Produce testosterone (male hormone) Scrotum – pouch outside of body that holds the testes Keeps testes cooler, necessary for proper sperm development Epididymis – structure on top of each testis, contains 6m of tubing Stores sperm until they are mature (20 days)

Sperm Male gamete Produced by meiosis in testes Parts Head – contains nucleus and chemical that allows it to pierce the egg Midpiece – mitochondria Tail – flagellum (mobility)

Seminal fluid and Semen Seminal fluid is produced by the prostate gland, bulbourethral gland, and Seminal vesicle Provides the sperm with nutrients, protection and chemicals needed to help ensure fertilization Sperm + seminal fluid = semen Males ejaculate 2-5 mL semen Each mL contains 50 to 130 million sperm

Transport of sperm out of the body Sperm leave the epididymis, and travel through the two vas deferens to where they join the urethra Vasectomy – cutting of both vas deferens Sperm are expelled from the body through the urethra during ejaculation

Testosterone Male sex hormone Male sex hormone Produced by testes Produced by testes Responsible for sperm production and development of secondary sex characteristics Responsible for sperm production and development of secondary sex characteristics Traits that appear during puberty Traits that appear during puberty Facial/body hair, deepening of the voice, increased muscle mass Facial/body hair, deepening of the voice, increased muscle mass

Female Reproductive System

The Ovary and Oviduct Ovary – female gonad Ovary – female gonad Produces egg Produces egg Produces estrogen and progesterone (female sex hormones) Produces estrogen and progesterone (female sex hormones) Oviduct – tube leading from ovary to uterus Oviduct – tube leading from ovary to uterus Where FERTILIZATION occurs Where FERTILIZATION occurs

The Egg cell Female gamete Female gamete Surrounded by a follicle which provides it with protection and nourishment Surrounded by a follicle which provides it with protection and nourishment

Uterus, Cervix and Vagina Uterus Uterus Muscular pear-shaped organ Muscular pear-shaped organ Where IMPLANTATION and DEVELOPMENT occurs Where IMPLANTATION and DEVELOPMENT occurs Cervix – opening from vagina to uterus Cervix – opening from vagina to uterus Vagina – birth canal Vagina – birth canal

The Menstrual Cycle Monthly series of events that prepares the female body to go through fertilization and then care for the developing fetus Monthly series of events that prepares the female body to go through fertilization and then care for the developing fetus Lasts about 28 days (range days) Lasts about 28 days (range days) Involves release of egg (ovulation) and thickening of the uterine lining Involves release of egg (ovulation) and thickening of the uterine lining Usually only occurs when there is NO fertilized egg present in the female body Usually only occurs when there is NO fertilized egg present in the female body

Menstrual Cycle Days 1-5 – MENSTRUATION Days 1-5 – MENSTRUATION Uterine lining and unfertilized egg are shed from the body Uterine lining and unfertilized egg are shed from the body Day 6-14 – Follicular Phase Day 6-14 – Follicular Phase Egg matures Egg matures uterine lining thickens (with blood vessels) uterine lining thickens (with blood vessels) Day 14 – Ovulation Day 14 – Ovulation Egg is released from ovary Egg is released from ovary Day – Luteal phase Day – Luteal phase Follicle becomes Corpus luteum Follicle becomes Corpus luteum Uterus continues to thicken Uterus continues to thicken Body prepared to accept fertilized egg Body prepared to accept fertilized egg

Estrogen and Progesterone Female sex hormones Female sex hormones Produced by ovary Produced by ovary Controls production and release of egg AND helps prepare uterus to accept fertilized egg during implantation Controls production and release of egg AND helps prepare uterus to accept fertilized egg during implantation Controls development of secondary sex characteristics Controls development of secondary sex characteristics Breast development, widening of hip, increase in amount of fat tissue Breast development, widening of hip, increase in amount of fat tissue