Chapter 16 Compendum Review

I. Human Life Cycle
II. Male Reproductive System
III. Female Reproductive System
IV. Female Hormone Levels
V. Control of Reproduction
VI. Sexually Transmitted Diseases

I. Human Life Cycle
A. Reproductive system is fully functional when puberty is complete.
- Girls become sexually mature between ages 11 and 13.
- Boys between ages 14 and 16.
B. Reproductive Organs and their Functions:
- Testes in males produce sperm; Ovaries in females produce eggs.
- Sperm is in ducts until it exits penis; eggs are transported via unterine tubes into uterus.
- Penis delivers sperm to vagina.
- Fertilized egg develops in uterus.
- Testes and ovaries produce sex hormones that maintain the testes and ovaries and bring about maculinization and feminization of various features. In females, sex hormone is necessary to sustain pregnancy. (Mader 320)
(Insert Sperm picture / d21c.com / http://d21c.com/sandysez/nursing?D=D)
(Insert Egg picture / http://www.zmuc.dk/ / http://www.zmuc.dk/InverWeb/Dyr/Limnognathia/reproduction_UK.htm)
C. Events of Human Life Cycle:
- Meiosis
- Fertilization
- Fetal Development
- Birth
- Childhood/Adolescence
- Adulthood (Meiosis)
- Aging
- Death (Frolich PowerPoint Slide 4)
(Insert Human Life Cycle Picture / Frolich PowerPoint Slide 4)
D. Mitosis and Meiosis
- Each cell in the body has 46 chromosomes, carrying our DNA.
1d. Duplication Division: Mitosis. When a cell divides, each new cell also has 46 chromosomes.
- Mitosis occurs during growth and repair of tissues.
2d. Reduction Division: Meiosis: Takes place only in testes of males during production of sperm and in the ovaries of females during production of eggs.
- This process reduces the number of chromosomes from 46 (AKA diploid, or 2n number) down to 23 chromosomes (AKA haploid, or n number)
- Occurs in two successive division: Meiosis I and Meiosis II.
-Flagellated sperm is much smaller than the egg. It carries the chromosomes to the egg.
- Egg provides the new individual with cytoplasm in addition to chromosomes.
3d. Zygote: The first cell of a new human being.
- The zygote gets 23 chromosomes from the sperm, and 23 from the egg, so it has 46 altogether. (Mader 320)
(Insert Fertilization picture / http://www.talbotcentral.ucr.edu/ /
http://www.talbotcentral.ucr.edu/AAA_03C_research.html)
II. Male Reproductive System
A. The following organs are found in the male reproductive system:
- Testes: Male gonads: Primary Sex organ. Paired testes, suspended from sacs of scrotum.
- Epididymis: Sperm produced by testes mature here. Tightly coiled duct lying just outside each testis.
- Vas Deferens: Mature sperm leave epididymis and enter here, where they are stored for some time. Each Vas Deferens goes into abdominal cavity, where it curves around bladder and empties into ejaculatory duct. (Mader 321)
- There are millions of sperm in a few drops of testicular fluid. (Frolich PowerPoint Slide 6)
- Urethra: Place where ejaculatory ducts enter. (Mader 321) Located near base of penis. (Frolich PowerPoint Slide 6)
- Prostate Gland: Donut-shaped. Surrounds upper portion of urethra just below bladder.
- Bulbourethral Glands: Pea-sized. Lie posterior to the prostate on either side of urethra. Secretion makes semen "gelatinous".
1a. Semen: The fluid containing sperm in which sperm leaves the penis during ejaculation. (Mader 321)
- Ejaculation: sperm travel from testes, joined by semen, and are expelled through erect penis.
- Semen is made by prostrate, seminal and bulbourethral glands at base of penis. (Frolich PowerPoint Slide 6)
(Insert Male Reproductive System picture / Frolich PowerPoint Slide 6)
- Seminal Vesicles: Lie at base of bladder. Each has a duct that joins with a vas deferens.
- Semen contains prostaglandins, which are chemicals that cause the uterus to contract, thus helping propel sperm toward egg. (Mader 321)
B. Orgasm in Males
1b. Penis: Male organ of sexual intercourse.
- Long shaft and enlarged tip called "glans penis".
- Circumcision: Surgical removal of foreskin from glans penis.
- During sexual arousal, autonomic nerves release nitric oxide, which stimulates the production of cGMP, which causes smooth muscle walls to relax and erectile tissue to fill with blood. Veins that take blood away from penis are compressed, = erection.
- Erectile Dysfuntion: Erectile tissue doesn't expand enough to compress the veins.
- Ejaculation: Sperm enter urethra from each vas deferens, glands contribute secretions to seminal fluid, and contractions cuase it to be expelled from penis in spurts. (= male orgasm)
- Refractory period: Length of time during which stimulation does not bring about an erection, usually following ejaculation.
C. Male Gonads, the Testes
1c. Testes: Produce sperm and make male sex hormones. Lie outside abdominal cavity, in scrotum. Necessary to reside in scrotal sacs because body temp is too high internally to produce viable sperm.
- Scrotum helps regulate temp of testes by holding them farther away from body.
2c. Seminiferous Tubules and Interstitial Cells
- Testes composed of lobules: compartments which contain one to three coiled seminiferous tubules, which are packed with cells undergoing spermatogenesis, the production of sperm.
- Sertoli Cells: Support, nourish, and regulate the process of spermatogenesis.
(Mader 322-323)
- In walls of tubules, stem cells that give rise to sperm are constantly undergoing meiosis.
- Sperm are then collected in epididymis.
- Sperm that are not ejaculated are reabsorbed back into testicular tissue. (Frolich PowerPoint Slide 7)
(Insert Testis and Sperm picture / Frolich PowerPoint Slide 7)
3c. Sperm have three parts: a head, a middle piece, and a tail.
- Mitochondria: found in middle piece. Provide energy for movement of tail.
- Tail: Flagellum.
- Head: Contains nucleus covered by cap called acrosome, which stores enzymes needed to penetrate egg.
- Live for approx. 48 hours in female genital tract.
- Only 1 of millions of sperm penetrate egg (normally).
D. Interstitial Cells: Cells that secrete the androgens, or male sex hormones.
E. Hormonal Regulation in Males
1e. Hypothalamus: Ultimate control of testes' sexual function.
- Secretes hormone gonadotropin-releasing hormone (GnRH), which stimulates anterior pituitary to secrete gonadotropic hormones.
- Two types of gonadotropic hormones: Follicle-stimulating hormone (FSH) (in males, promotes production of sperm in seminiferous tubules), and Luteinizing hormone (LH) (in males, controls production of testosterone by interstitial cells).
- All hormones are involved in negative feedback relationship that provides a continuous production of sperm and testosterone.
2e. Testosterone: Main sex hormone in males. Essential for development and functin of sex organs. Brins about and maintians male secondary sex characteristics present during puberty. (Hair on face, etc.)
III. Female Reproductive System
A. Female gonads are paired ovaries, found on either side of the upper pelvic cavity.
- Produce eggs and the female sex hormones, estrogen and progesterone.
B. Genital Tract:
1b. Oviducts: (AKA fallopian tubes): EXtend from uterus to ovaries, but are not attached to ovaries.
- Fimbriae: Finger-like projections extending from oviducts that sweep over ovaries and carry them into an oviduct with the help of beating cilia that line oviducts. Moves toward uterus.
- Egg lives approx. 6-24 hours, unless fertilization occurs.
- Fertilization takes place in oviduct.
- Implantation: Embryo moves from oviduct to uterus and embeds in uterine lining.
2b. Uterus: Thick-walled, muscular organ. Lies above and tipped over urinary bladder. Oviducts join uterus at upper end, cervix enters vagina at lower end.
- Development of embryo / fetus occurs here.
- Endometrium: Lining of uterus. Helps form placenta, shich supplies nutrients for embryo / fetus.
3b. Vagina: Tube. Serves as birth canal, facilitates sexual intercourse, and acts as exit for menstrual flow.
(Insert Female Reproductive System picture / http://www.faqs.org/ / http://www.faqs.org/health/Body-by-Design-V2/The-Reproductive-System.html)
- Pap test: tests for cancer of cervix by removing cells from cervix for microscopic examination.
- Hysterectomy: Removal of uterus, including cervix. (Mader 325)
C. External Genitals: The Vulva
- Labia majora
- Labia minora: Cleft between labie minora contains openings of urethra and vagina.
- Glans clitoris: organ of sexual arousal. Contains shaft of erectile tissue.
D. Orgasm in Females
1d. Labia minora becomes engorged with blood. Blood vessels in vaginal wall release drops of fluid for lubrication. Clitoris is stimulated, and orgasm occurs when walls of uterus contract. (Mader 326)
IV. Female Hormone Levels
A. Ovarian Cycle: Nonpregnant
1a. Ovary contains multiple follicles, and each follicle contains an immature egg, called an oocyte.
- Female produces 1 egg per month.
- Ovarian Cycle: Follicle matures.
- Oocyte develops into a corpus luteium, a glnadlike structure.
- Oogenesis: Primary oocyte undergoes meiosis I. (Mader 326)
- Meiosis occurs in ovaries.
- Phase I occurs in fetal ovary.
- One egg per month (ovulation part of menstrual cycle) matures and bursts from wall of ovary to be taken up into Fallopian tube.
- Phase II of meiosis occurs the moment the egg is fertilized (if that happens). (Frolich PowerPoint Slide 10)
- Primary follicle: produces estrogen.
- Secondary follicle: produces estrogen and some progesterone.
2a. Phases of Ovarian Cycle:
- Hypothalamus: Controls the sexual function of ovaries.
- Secretes gonadotropin-releasing hormone (GnRH), which stimulates the production of FSH and LH, which control ovarian cycle.
- Positive Feedback Effect: Estrogen spike causes secretion of large amount of GnRH from hypothalamus, which leads to a surge of LH, which leads to ovulation.
- Luteal Phase: LH promotes development of corpus luteum, which secretes progesterone.
B. Estrogen and Progesterone:
- Affect uterus, etc.
- Estrogen: Responsible for secondary sex characteristics (breast development, etc.)
- Menopause: Ovarian cycle ceases, between ages 45-55.
C. Uterine Cycle: Non-pregnant:
1c. Uterine Cycle:
- Low level of estrogen and progesterone in body causes endometrium to disintegragte and its blood vessels to rupture. = menstruation (days 1-5)
- Increased production of etrogen causes endometrium to thicken. (days 6-13)
- Ovulation occurs. (day 14)
- Increased production of progesterone in ovary causes endometrium of uterus to double or triple in thickness. Thick mucoid secretion, prepared to receive embryo. (days 15-28). If no embryo is received, corpus luteum regresses, and low level of sex hormones result in endometrium breaking down for menstruation. (Mader 328-329)
(Insert Female Hormone Levels picture/ Frolich PowerPoint Slide 11)
D. Fertilization and Pregnancy:
1d. Placenta: Sustains devedloping embryo and fetus, comes from both maternal and fetal tissues.
- Produces human chorionic gonadotropin (HCG), which maintains corpus luteum in ovary.
- Rising amounts of HCG stimulates corpus luteum to produce progesterone, which shuts down hypothalamus so no new follicles begin in ovary.
- Progesterone maintains uterine lining for embryo.
- Eventually, the placenta itself takes over production of progesterone and some estrogen, so corpus luteum is no longer needed and it regresses. (Mader 330)
(Insert Effect of Pregnancy picture / Frolich PowerPoint Slide 12)
V. Control of Reproduction:
A. Birth Control
- Abstinence
- The pill
- Intrauterine device
(Insert Intrauterine Device picture / http://www.fiu.edu/ / http://www.fiu.edu/~srose/abortioncontracep.html)
- Hormone skin patch
- Depo-Provera
- Diaphragm and spermicidal jelly
- Condoms (male and female)
- Implants (Mader 331)
B. Vasectomy and Tubal Ligation:
1b. Sterilization.
- Vasectomy: Cuts and seals the vas deferens on each side so the sperm are unable to reach the seminal fluid, and are reabsorbed.
(Insert Vasectomy picture / Frolich PowerPoint Slide 8)
- Tubal Ligation: Cuts and seals the oviducts, so the passage of egg is blocked.
(Insert Tubal Ligation picture / http://www.mala.bc.ca/ / http://www.mala.bc.ca/incline/tubals.html)
C. Morning-After Pills
- "Emergency Contraception": Medication upsets normal uterine cycle, so an embryo can't implant itself. Causes loss of unimplanted or implanted embryos.
D. Infertility: Failure of a couple to achieve pregnancy after one year of regular, unprotected intercourse.
- Consitutes approx. 15% of american couples.
1d. Some causes:
- Low sperm count. (Associated with smoking and drinking.)
- Body weight in females causes failure to ovulate.
- Blocked oviducts due to pelvic inflammatory disease and endometriosis.
E. Assisted Reproductive Technologies:
- Artificial Insemination by Donor
- In Vitro Ferilization
- Gamete Intrafallopian Transfer (Egg and Sperm placed in oviducts immediately after they are brought together, whereas in In Vitro, eggs are brought to maturity in glassware, sperm are added, and after about 2-4 days, implanted in woman.)
- Surrogacy
- Intracytoplasmic Spermm Injection: single sperm injected in egg. (Mader 334)
VI. Sexually Transmitted Diseases
A. Caused by viruses, bacteria, protists, fungi, and animals.
1a. STD's caused by Viruses:
- Drugs used fro treatment of these STDs only slows replication of virus: does not cure.
2a. HIV Infections: AIDS is last stage of an HIV infection.
- Approx. 38.6 million affected worldwide.
- Approx. 25 million have died.
- Helper T lymphocyte: primary host for HIV. These are the same cells that stimulate immune response, and the immune system becomes severely impaired.
- Highly contagious in first stage. Minimal symptoms.
- Helper T lymphocyte count eventually falls, and the person becomes susceptible to all kinds of illnesses.
- Persons usually die from an opportunistic disease, such as pneumonia.
3a. Genital Warts:
- Caused by human papillomaviruses.
- Warts are seen on penis and foreskin of men and near vaginal opeining in women.
- New vaccine is now available.
4a. Genital Herpes:
- Caused by herpes simplex virus.
- Type 1- Cold sores and fever blisters.
- Type 2- Genital Herpes.
- Tingling / itching sensation. Blisters on genitals, which rupture and leave blisters. Increased risk of acquiring HIV.
- Symptoms are recurrent.
(Insert Genital Herpes picture / http://www.femail.com.au/)
5a. Hepatitis:
- Infects liver, and can lead to liver failure, liver cancer, and death.
- Six Viruses, labeled: A, B, C, D, E, and G.
- A & E are usually from contiminated water! (Mader 336-337)
- Hep B: most commonly sexually transmitted hepatitis.
- Transmitted through sexual contact and by contaminated blood.
- Vaccine available for both Hep A and B. (Frolich PowerPoint Slide 15)
B. STDs Caused by Bacteria:
- Curable with antibiotics.
1b. Chlamydia: Caused by tiny bacterium.
- Usually mild or asymptomatic.
- Increases risk of HIV.
- If untreated, infection can spread from cervix to uterine tubes, resulting in pelvic inflammatory disease. Very painful. Causes infertility.
2b. Gonorrhea:
- Latent infection leasds to pelvic inflammatory disease, which can cause sterility in males.
- Gonorrhea proctitis: infection of anus.
- Gonorrhea can spread to internal parts of body, causing heart damage or arthritis.
- Now showing resistance to antibiotics.
3b. Syphilis:
- Treated w/ penicillin.
- Three stages: Primary- hard chancre (ulcerated sore with hard edges) indicates site of infection. Second Stage- Rash occurs even on palms and soles of feet. Hair loss, gray patches on mucous membranes may occur. Tertiary Stage- Lasts until patient dies. Affects cardiovascular system by causing aneurysms, particularly in aorta. Can also affect nervous system, causing psychological disturbances. Also, gummas, large ulcers, may develop on skin or within internal organs.
- Congenital Syphilis: bacteria passees into placenta and child is born blind or with many malformations. (Mader 338)
4b. Other Common Infections of Reproductive Tract:
* Bacterial vaginosis (BV):
–Accounts for ~ 50% of vaginitis in American women.
–Caused by a disruption of the normal flora in the vagina leading to an overgrowth of certain bacteria.
* Trichomoniasis
–Caused by a protozoan.
–Can cause a frothy discharge, with a foul smell and itching.
–Common cause of vaginitis.
* Candidiasis
–An overgrowth of normal yeast (fungus called Candida) in the vagina.
–Characterized by tissue that is red, inflammed and itchy; sometimes a white, curdy discharge as well.
–Birth control hormones and use of antibiotics make women more prone to this overgrowth.
(Frolich PowerPoint Slide 16)
C. Prevention of STDs
• Abstinence.
• Develop long-term monogamous relationships.
• Be aware if your partner is an intravenous drug user because prevalence of STDs are higher in that group.
• Practice safer sex.
– Always use a latex condom during intercourse.
–Limit or do not use alcohol and drugs that can impair your judgment or change your behavior. (Frolich PowerPoint Slide 17)