12-2 Objectives

1. 12-2 Objectives • * What is a system? (See slide 2) • * What are the individual functions of each structure within the male reproductive system? • * Where are each of the structures located within the male reproductive system?

2. sys·tem noun \ˈsis-təm\ : a group of related parts that move or work together : a body of a person or animal thought of as an entire group of parts that work together : a group of organs that work together to perform an important function of the body

3. Male Reproductive System 12-2 • Puberty-period of sexual development during which males and females become capable of reproducing. • Changes at Puberty • ? • ? • ? • ? • ? • Fertilization-Joining of an egg cell with a sperm cell.

4. Structures & Functions of theMRS • Testes-Have two major functions • Produce testosterone • Produce sperm cells • Scrotum- Hold the testes outside the body and regulates the temperature of the sperm cells. They can’t survive at 98.6 Needs to be slightly lower! • Epididymis-”J” shaped tube on the back of each teste used to store sperm for 2-4 days until they mature.

5. 3 Glands along the MRS which add fluids to sperm cells to create the fluid known as semen. • Seminal Vesicle • Cowper’s Gland • Prostate Gland • Vas Deferens-An 18 inch tube that receives sperm from the epididymis and runs to the urethra. • Urethra-Tube which passes through the penis to the outside of the body. Both urine and sperm cells pass through the urethra to the outside of the body but cannot do so at the same time. A valve closes off the bladder during sexual arousal.

6. Spermatogenesis • The process by which sperm are produced. • FSH, LH, & Testosterone are the 3 hormones responsible for spermatogenesis. • Approximately 400 million sperm cells are released during a normal ejaculation. Why?

7. Disorders of the MRS • Undescended Testes-when one of the testes does not drop into the scrotum during the development process. • Inguinal Hernia-when part of the intestines breaks through into the scrotum. • Prostate & Testicular Cancer-p.281

8. Female Reproductive System(12-3) • Changes at Puberty- • ? • ? • ? • ? • ?

9. Structures and Functions of theFRS • Similarities between the MRS & FRS? • Ovaries-Have 2 functions • Release of female hormones estrogen and progesterone. • Produce and release mature egg cells. Each ovary contains 200,000 egg cells, present from birth. Ovulation-Release of an egg cell every 28 days.

10. More Structures & Functions ofFRS • Fallopian Tubes-oviducts, carry the released egg from the ovary to the uterus. Small hairs (cilia) sweep the egg through the tube. Inside diameter is no larger than a strand of hair! Where fertilization takes place. • Uterus-The womb. The inside lining is called the endometrium. This is where the fertilized egg implants. • Cervix-base of the uterus that leads to vagina.

11. Disorders of the FRS • Pre-Menstrual Syndrome-Severe discomfort before menstruation. Marked by nervous tension, mood swings, headaches, bloating, irritability, Believed to be caused by dramatic changes in hormone levels. Equivalent to? • Ovarian, Cervical & Breast Cancer-p.288 • Pap Test-Recommended for women over 20

12. The Menstrual Cycle • The process by which women produce and release egg cells. • 0-14 Endometrium rebuilds • 14-21 Egg released from ovary & travel fallopian tube • 21-28 Endometrium breaks down and is discharged from body.

13. 12-3 continued… • Menopause-ovaries slow down hormone production & no longer release mature egg cells. Approximately between the ages of 45-55. • Endometriosis-when the endometrium grows somewhere other than the uterus. p.285

14. Heredity(12-4) • The passing on or transmission of biological traits from parent to child. • Chromosomes-tiny structures in every cell that carry info. about the characteristics. • Each cell in our body contains 23 pairs of chromosomes. 23 from each sex cell, or parent. • DNA-Deoxyribonucleic Acid=chemical substance that makes up chromosomes.

15. 12-4 cont. • Genes-a section of chromosome that determines a specific trait. ie) eye color, hair color, straight hair, curly hair • Genes are either Dominant or Recessive • Recessive-are only expressed when another recessive gene is present • Dominant-Are always expressed when present

16. Dominant Brown Eyes Curly Hair Freckles Dimples Recessive Blue Eyes Straight Hair Blond Hair Pug nose Dominant & Recessive Traits

17. Sex Determination • Among the 23 pairs of chromosomes, 1 pair is the sex chromosomes. • All egg cells contain X chromosomes • 1/2 of the 400 million sperm cells are X, the other 1/2 are Y. • X,X=Females • X,Y=Males • Figure 12-14

18. Genetic Disorders • Any abnormal condition that a person inherits through genes. Defective genes are usually what cause genetic disorders. • There are recessive and dominant genetic disorders. However, most are recessive! What must happen then for someone to actually have a genetic disorder? What is a carrier?

19. Disorders • Sickle Cell Anemia-Recessive blood disorder. Abnormally shaped RBC. Frequent among African Americans. Usually fatal. • Tay-Sachs-Recessive disorder characterized by the lack of an important chemical in the brain. Frequent among Eastern Europeans. Usually fatal by age 5. • Cystic Fibrosis-Recessive disorder of the lungs. Glands produce too much mucus for the lungs to handle. Life expectancy is early adulthood.

20. Sex Linked Disorders • Recessive disorder that affects the X chromosomes only of sex chromosome pair. • Which sex do you think sex linked disorders are more common in? • Color blindness and hemophilia are examples of sex linked disorders.

21. Down Syndrome • Caused by receiving an extra chromosome at the 21st pair. • Distinct physical appearance: • Shortened height and limbs • Almond shaped eyes • Rounded face • Mental retardation ranging from mild to severe. Can lead a normal life within reason.