1. The Reproductive System Overview
Chapter 21
Biology 12

2. Overview/Objectives 21.1- Male Reproductive System
Male anatomy
Testes and how they relate to sperm production and male sex hormones
Hormone regulation in males
21.2- Female Reproductive System
Female anatomy
External genetals and orgasm
21.3- Female Hormone Levels
Hormonal control of the uterine cycle, ovarian cycle, and maintaining pregnancy
Hormones that control the sex characteristics of females
21.4- Control of Reproduction
Birth control and conceiving methods
21.5- Sexually transmitted diseases

3. Similarities and differences between males and females, but same goal: new life
Primary sex organs: gonads
Testes in males
Ovaries in females
These produce the gametes (sex cells)
Sperm in males
Ovum (egg) in females
Endocrine function also: secretion of hormones
Accessory sex organs
Internal glands and ducts
External genitalia

4. 21.1- Male Reproductive System

5. Epididymis  vas deference  urethra
Male Genital Tract
Organ
Function
Testis
Produce Sperm and sex hormone
Epididymis
Duct when sperm mature and are stored
Vas Deference
Conducts and store sperm
Seminal vesicle
Contributes nutrients and fluid to semen
Prostate gland
Contributes basic fluid to semen
Urethra
Conducts sperm
Bulbourethral gland
Contributes mucoid fluid to semen
Penis
Organ of sexual intercourse
Path of Sperm:
Epididymis  vas deference  urethra

6. Male Anatomy

7. Male Gonads: The Testes
Testes – produce sperm and male sex hormones
Location: outside the abdominal cavity in the scrotum  because inside temp. is too high for viable sperm  scrotum regulates the temperature of the testes
Composition: seminiferous tubules (tightly coiled tubules)  contains cells undergoing spermatogenesis (production of sperm)

8. Testes Anatomy

9. Sperm Anatomy

10. Hormonal Regulation in Males
Male sex hormones = androgens  secreted by interstitial cells in the testes
Testosterone is the most important androgen  brings about and maintains male secondary sex characteristics:
Bone density > females/ heavier muscle mass
Height > females/ longer legs
Broader shoulders
Deeper voice
Facial/Chest hair
Anabolic steroids = increase these characteristics, but eventually hormonal imbalances cause testes to shrink in size and feminization of other male traits

11. Hormonal Regulation in Males
Hypothalamus (brain)
2 Gonadotropic Hormones:
LH = luteinizing hormone
FSH= Follicle stimulating hormone
LH & FSH are in both males & females
GnRH = Gonadotropin Releasing Hormone
Anterior Pituitary (brain) LH
FSH
Controls production of testosterone
Stimulates production of sperm
Turns off Anterior Pituitary and Hypothalamus (Negative Feedback)
Inhibin- turns off Anterior Pituitary and Hypothalamus (Negative Feedback)

12. 21.2- Female Reproductive System

13. Ovary fallopian tube uterus vagina
Female Genital Tract
Organ
Function
Ovary
Produces egg and sex hormones
Oviduct (fallopian tubes)
Conducts egg; location of fertilization
Uterus (womb)
Houses developing fetus
Cervix
Contains opening to uterus
Vagina
Receives penis during sexual intercourse; serves as birth canal and exit for menstrual flow
Path of the egg:
Ovary fallopian tube uterus vagina

14. Female Anatomy

15. 21.3- Female Hormone Levels
Structure of the Ovary:
Consists of outer cortex and inner medulla
Cortex contains many follicles, each containing an immature egg oocyte
Females are born with ~ 2 million follicles, only 1 egg/month matures during reproductive years
Oocytes age as women age, which is why older women have a higher chance of producing children with genetic defects

16. The Ovarian Cycle
Estrogen & Progesterone = female sex hormones that affect the endometrium and cause the uterine cycle
Follicular phase (Days 1-13)
FSH secretion begins
Follicle maturation occurs
Estrogen secretion is prominent
Ovulation (Day 14)
LH spike occurs
Luteal Phase (Day 15-28)
LH secretion continues
Corpus luteum forms
Progesterone secretion is prominent

17. The Ovarian Cycle Pituitary hormones FSH: follicle stimulating hormone
LH: luteinizing hormone

18. The Uterine Cycle Menstruation (Days 1-5) – endometrium breaks down
Proliferative Phase (Days 6-13) – endometrium rebuilds  due to estrogen production
Secretory Phase (Days 15-28) – Endometrium thickens and glands are secretory  due to increase production of progesterone

19. The Uterine Cycle Proliferative phase: rebuilds itself after slough
Secretory phase: vascular rich glands enlarge: will sustain baby (needs progesterone: corpus luteum initially then placenta)
Ovarian hormones
Estrogen
Progesterone

20. (inhibin: inhibits pituitary secretion of FSH)

21. Menstration Endometrium lining, mucus and blood are shed
Fibrinolysin = enzyme released by dying cells that prevents blood clotting
Why is it painful?
Prostaglandin levels are higher  causes muscle contractions
Did you know the pain of period cramps can be reduced with a diet high in fiber (fruit and vegetables), natural bacteria (yogurt), and low in sugar!

22. Fertilization and Pregnancy
If fertilization of the oocyte occurs in the fallopian tubes between days 14-22, an embryo begins to develop
The developing embryo implants in the endometrium (lining of the uterus)
The placenta, originates from both fetal and maternal tissues and produces human chorionic gonadotropin (HCG) which maintains the corpus luteum in the ovary until the placenta is developed enough to produce its own estrogen & progesterone (the pregnancy hormone)

23. Fertilization & Pregnancy Continued
Pregnancy tests look for HCG (a molecule present only during pregnancy  no false positives)
Progesterone & Estrogen do 2 things:
Stop anterior pituitary from maturing a new follicle
Maintain the endometrium

24. 21.4- Control of Reproduction
Birth Control Methods
Abstinence = most reliable
Contraceptives (medication & devices that reduce chance of pregnancy)
Oral Contraceptive (Birth control pill)
Intrauterine device (IUD)
Female and male condom
Contraceptive implants
Contraceptive Injections & Vaccines
Most contraceptives are not 100% reliable, and they do not protect from STD’s. Also, some increase your risk of cancer and decrease future fertility.

25. 21.5- Sexually transmitted diseases
Acquired Immunodeficiency Syndrome (AIDS)
HIV Infections
Genital herpes
Genital warts
Hepatitis Infections
Hepatitus B
Chlamydia
Gonorrhea
Syphilis