1. The Reproductive System Advanced Human Anatomy

2. Wednesday (5/6) – Reproductive System Notes Friday (5/8) – Study Guide for Final (Digestive, Urinary, Reproductive – 85 Qs) Tuesday (5/12) – Finish Reproductive System; Cat Pre-Lab Thursday (5/14) – Cat Dissection Monday (5/18) – Cat Dissection Thursday (5/21) – Cat Dissection Schedule! FRIDAY May 22 nd A-day TUESDAY May 26 th B-day WEDNESDAY May 27 th A-day THURSDAY May 28 th B-day 8:25 – 9:27A1 class B1 class A2 classB2 class 9:32 – 11:32A2 FINAL B2 FINAL A1 FINALB1 FINAL 11:37 – 1:40A3 class B3 class A4 classB4 class 1:45 – 3:45 A4 FINALB4 FINAL A3 FINALB3 FINAL Please, start bringing your anatomy books back ASAP!

3. Sexual Development In humans, the reproductive system produces, stores, and releases specialized sex cells known as gametes. ◦ Haploid cells ( 23 chromosomes ) ◦ Sperm – male // Egg – female These cells are released to create the fusion of sperm and egg to form a zygote, the single cell from which all cells of the human body develop. Human male and female embryos are identical until they begin to differentiate at about 7 weeks of development.

4. Key Hormones FSH : follicle stimulating hormone; promotes the formation of ovaries and sperm. LH : luteinizing hormone; stimulates testosterone production in males and female production of estrogen Testosterone : main male sex hormone; secretion by the fetal testis cells is responsible for the development of certain parts of the male genitals; increased in puberty Estrogen : primary female sex hormone; plays a role in menstruation Progesterone : female hormone important for the regulation of ovulation and menstruation

5. Sexual Development ~ Puberty Puberty is a period of rapid growth and sexual maturation during which the reproductive system becomes fully functional.  When puberty ends, reproductive organs are fully developed.  Puberty usually begins between the ages of 9 and 15, and usually starts one year earlier in females than in males.

6. Secondary Sexual Characteristics FemaleMale Induced by increased LH, FSH, estrogen, and progesterone hormone levels ◦ Pubic hair ◦ Widen pelvis ◦ Enlarge mammary tissue (breasts) ◦ Begin menstrual cycles Induced by testosterone ◦ Deeper voice ◦ Chest, pubic, facial hair ◦ Lengthen bones ◦ Increased size of testes for sperm production

7. Male Reproductive System The main function of the male reproductive system is to produce and deliver sperm.  Release of FSH and LH stimulates cells in the testes to produce testosterone.  FSH and testosterone stimulate the development of sperm. Primary male reproductive organs are the testes Accessory organs = penis, scrotum

8. Sperm Cells A sperm cell consists of: ◦ Head, which contains the nucleus ◦ Midpiece, which contains energy- releasing mitochondria ◦ Tail, which propels the cell forward Sperm are motile, produced in large numbers, and smaller than most cells Head Nucleus Midpiece Mitochondria Tail

9. The Male Reproductive System Male Reproductive System Urinary bladder Vas deferens Pubic bone Urethra Penis Seminal vesicle Rectum Prostate gland Bulbourethral gland Scrotum Testis Epididymis

10. The Male Reproductive System The testes are located in an external sac called the scrotum. The scrotum is located outside the body cavity, where it is between 1 and 3 degrees cooler than normal body temperature. The lower temperature helps sperm development.

11. The Male Reproductive System Within each testis are clusters of hundreds of tiny tubules called seminiferous tubules. ◦ The seminiferous tubules are tightly coiled and twisted together. ◦ Sperm are produced in the seminiferous tubules. ◦ Sperm produced in the seminiferous tubules move into the epididymis, where they mature and are stored.

13. The Male Reproductive System From there, sperm move into a tube called the vas deferens, which extends up from the scrotum into the abdominal cavity. This merges with the urethra, the tube that leads to the outside of the body through the penis.

14. The Male Reproductive System Glands lining the reproductive tract produce seminal fluid. ◦ The Cowper’s glands (or bulbourethral glands) are a pair of exocrine glands in the male reproductive system  Produce pre-ejaculate which neutralizes acidic urine that may still be present in the urethra; lubricates the urethra and external urethral orifice to protect sperm from mechanical damage during ejaculation ◦ Prostate gland produces seminal fluid nourishes sperm and protects them from the acidity of the female reproductive tract. ◦ The combination of sperm and seminal fluid is called semen.  1 drop = approximately 3-5 million sperm cells  Ejaculation = 300 – 600 million sperm cells

15. The Female Reproductive System The main function of the female reproductive system is to produce eggs. In addition, the female reproductive system prepares the female's body to nourish a developing embryo. The primary reproductive organs in the female are the ovaries. ◦ The ovaries are located in the abdominal cavity. Accessory organs: uterus, fallopian tube, breasts, and vagina

16. The Female Reproductive System Fallopian tube Ovary Uterus Urinary bladder Pubic bone Urethra Vagina Rectum Cervix Female Reproductive System

17. Egg Development Each ovary contains about 500,000 primary follicles, which are clusters of cells surrounding a single egg (only about 400 are active) The follicle helps an egg mature for release into the reproductive tract, where it can be fertilized. ◦ Eggs develop within their follicles. Unlike men, who produce new sperm daily throughout most of their lifetime, women are born with all their eggs. ◦ To be more precise, a woman is born with about one to two million immature eggs, or follicles, in her ovaries ◦ This number has decreased to about 400,000 eggs stored in her ovaries. ◦ From puberty to the menopause only about 400-500 eggs will reach maturity, be released from the ovary, and be capable of being fertilized

19. Egg Release ~ Ovulation  When a follicle has matured, its egg is released in a process called ovulation.  The follicle breaks open, and the egg is swept from the ovary into one of the two Fallopian tubes.  While in the Fallopian tube, an egg can be fertilized.  After a few days, the egg passes from the Fallopian tube into the uterus.  hollow muscular organ of the female reproductive system that is responsible for the development of the embryo and fetus during pregnancy  If the egg is not fertilized it passes through the cervix, and finally out of the vagina.  The vagina leads to the outside of the body.

20. The Reproductive System Day 2 Notes

21. The Menstrual Cycle The menstrual cycle is controlled by internal negative feedback mechanisms between the reproductive system and the endocrine system. ◦ Negative feedback mechanisms reduce the variable back to its original state or “ideal value”. ◦ The cycle takes an average of 28 days.

22. The Menstrual Cycle During the menstrual cycle, an egg develops and is released from an ovary. The uterus is prepared to receive a fertilized egg. If the egg is fertilized, it is implanted in the uterus and embryonic development begins. If the egg is not fertilized, it is discharged.

23. The Menstrual Cycle The menstrual cycle has four phases: ◦ Follicular phase ◦ Ovulation ◦ Luteal phase ◦ Menstruation During these phases, hormone levels vary ◦ FSH, LH ◦ Progesterone ◦ Estrogen

24. The Menstrual Cycle Follicular Phase  The anterior pituitary secretes FSH and LH, which cause a follicle to develop to maturity  As the follicle develops, cells surrounding the egg enlarge and produce more estrogen.  Estrogen causes the lining of the uterus to thicken. Ovulation  This phase occurs midway through the cycle and lasts 3–4 days.  The pituitary gland produces more FSH and LH.  The release of these hormones causes the follicle to rupture, and a mature egg is released into one of the Fallopian tubes.

25. The Menstrual Cycle Luteal Phase The luteal phase begins after the egg is released. As the egg moves in the Fallopian tube, the follicle turns yellow and is called the corpus luteum. The corpus luteum continues to release estrogen but also begins to release progesterone. Menstruation  If fertilization does not occur, the corpus luteum will begin to disintegrate.  The follicle breaks down and releases less hormones, which makes the uterine lining detach.  This tissue, blood, and the unfertilized egg are discharged through the vagina.  This phase is menstruation, and it lasts 3–7 days If fertilization does occur… whole different ballgame….

26. The Menstrual Cycle Ovulation

27. Fertilization Occurs in upper 1/3 of Fallopian tube Only 1 sperm can fertilize an egg Fertilized egg = zygote Progesterone stimulates growth and development of the blood supply and surrounding tissue. Within a few days of implantation, the uterus and the growing embryo will release hormones that keep the corpus luteum functioning for several weeks. This allows the lining of the uterus to nourish and protect the developing embryo

28. Implantation Fertilized eggs are implanted into thick walls of uterus Chorion membranes dig into uterus to form placenta Zygote grows into an embryo Embryo gets air and nutrients through the umbilical cord Once pregnant, progesterone levels stay high in mom Mom’s uterus grows with the baby

29. Duration of Pregnancy First Trimester – 1 st 12 Weeks Heart develops first Neural tube develops All body systems appear by Week 8 – Now a Fetus Second Trimester – 13-27 Weeks Most growth Looks more like a baby Some premature births can survive at this stage Third Trimester – 28-40 Weeks More growth Kicking, rolling, stretching Eyes open – Week 32 Lungs mature Rotates to head-down position, unless baby is breech

30. Birth Labor ◦ Uterine contractions begin ◦ Cervix dilates to 10 cm. Birth ◦ Uterus pushes baby through vaginal canal ◦ Placenta delivered after baby ◦ Cesarean Section (c-section) is a surgery that cuts through the uterus to deliver the baby if it cannot be born vaginally