1. Inquiry into Life Twelfth Edition
Lecture PowerPoint to accompany
Inquiry into Life Twelfth Edition
Sylvia S. Mader
Chapter 21
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2. 21.1 Male Reproductive System
Genital Tract
Sperm are produced by seminiferous tubules of testes
Undergo maturation in the epididymis
Maturation involves gaining of motility
Sperm pass through vasa deferentia where products are secreted by glands that contribute to semen
Seminal vesicles
Prostate
Bulbourethral glands
Semen is alkaline and contains fructose and prostaglandins

3. The Male Reproductive System

5. Penis Anatomy

6. 21.1 Male Reproductive System
Orgasm in Males
Sexual excitement increases blood flow to the penis causing an erection
Sperm enters the vasa deferentia, glands contribute secretions to the semen
Semen is ejaculated
Ejaculation is followed by a refractory period
Over 400 million sperm cells may be ejaculated

7. 21.1 Male Reproductive System
Male Gonads, the Testes
Produce sperm and hormones
Located outside of the body cavity
Internal body temperature is too high for sperm production
Scrotum helps regulate temperature of the testes

8. A Testis Spermatogenesis occurs in the seminiferous tubules
Sertoli cells support, nourish, and regulate spermatogenic cells.
Interstitial cells produce testosterone

9. A Sperm Cell Three Main Parts Head Middle Piece Tail
The acrosome contains enzymes needed to penetrate an egg
Middle Piece
Many mitochondria
Tail
Flagellum

10. 21.1 Male Reproductive System
Hormonal Regulation in Males
Gonadotropin Releasing Hormone (GnRH) from the hypothalamus causes the anterior pituitary to release Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH)
FSH targets seminiferous tubules- stimulates sperm production
LH stimulates interstitial cells of the testes to produce testosterone
All are regulated by negative feedback
Testosterone is responsible for male secondary sex characteristics

11. Hormonal Control of Testes

12. 21.2 Female Reproductive System

14. External Genitals of the Female

15. 21.2 Female Reproductive System
Orgasm in Females
Labia minora, vaginal walls,clitoris become engorged
Erection of nipples
Secretion of vaginal fluids, mucus for lubrication
Vagina is the organ of intercourse, clitoris plays an important role in excitation and orgasm
Height of excitation- increased heart rate, blood pressure, and smooth muscle contractions
Females have no refractory period following orgasm

16. 21.3 Female Hormone Levels

17. Ovarian Cycle

18. Hormonal Control of the Ovaries
The hypothalamus, anterior pituitary and ovaries all function to control female hormone levels. Like other hormones, female hormones are regulated by feedback mechanisms.

19. 21.3 Female Hormone Levels
Female cycles are studied based on an average of 28 days
The Ovarian Cycle The Uterine Cycle
Two Phases Three Phases
Follicular Phase Menstruation
Luteal Phase Proliferative Phase
Secretory Phase

20. Ovarian and Uterine Cycles

22. 21.3 Female Hormone Levels Menstruation
Arteries that supply the endometrium (uterine lining) constrict thereby weakening the capillaries
The endometrium detaches in random patches
Tissue, blood, and mucus are lost in the menstrual flow
Menstruation lasts days

23. 21.3 Female Hormone Levels Fertilization and Pregnancy
An embryo begins development in the oviduct
Implantation occurs when embryo migrates into uterus
Embryo begins to produce human chorionic gonadotropin (hCG)
hCG maintains the corpus luteum to prevent a drop in levels and estrogen and progesterone
Pregnancy tests detect hCG
Later, the placenta will secrete estrogen and progesterone
Estrogen and progesterone prevent ovulation and help to maintain the endometrium

24. 21.3 Female Hormone Levels Estrogen and Progesterone
Both have effects other than those in the ovarian and uterine cycles
Estrogen
Maintains female secondary sex characteristics
Breast development, axillary and pubic hair, subcutaneous fat deposition
Wider pelvis
Progesterone
Also needed for breast development

25. 21.3 Female Hormone Levels Menopause
Generally occurs between the ages of
Ovaries become unresponsive to FSH and LH
At the onset of menopause, the menstrual cycle becomes irregular. Other characteristics include hot flashes, dizziness, headaches, insomnia and depression.
Menopause is complete when menstruation has not occurred for one year
Hormone replacement therapy has advantages and disadvantages

26. 21.4 Control of Reproduction

28. 21.4 Control of Reproduction
Morning-After Pills
Emergency contraception
Taken after intercourse has occurred
Two types, both disrupt uterine environment
Preven - series of progesterone pills that disrupts normal cycle making implantation difficult
RU-486 (mifepristone) - blocks progesterone receptors in the uterus so that the endometrium is sloughed off
In 2006, a non-prescription drug was approved by the United States Food and Drug Administration

29. 21.5 Disorders of the Reproductive System
Sexually Transmitted Diseases

30. 21.5 Disorders of the Reproductive System (STD’s)
AIDS
Acquired Immunodeficiency Syndrome
Caused by HIV (human immunodeficiency virus)
Transmission
Sexual Contact
Vaginal or anal intercourse
Oral / genital contact
Intravenous drug use
Birthing process
Breast feeding
Primary host cells are helper T-cells

31. 21.5 Disorders of the Reproductive System (STD’s)
Stages of an HIV Infection
Upon initial infection with HIV, the virus replicates rapidly in macrophages and CD4+ T cells (helper)
HIV quickly spreads through lymphatic tissues
Early symptoms may include fever, chills, aches and swollen lymph nodes, these symptoms then subside
Antibodies against HIV appear several weeks after exposure
The basis of HIV tests

32. 21.5 Disorders of the Reproductive System (STD’s)
Stages of an HIV Infection
Eventually, the number of CD4+ T cells (helper T cells) begins to decline
A person is in the later stages of the disease when the CD4+ T cell count is 200 cells per mm3 or lower

33. 21.5 Disorders of the Reproductive System (STD’s)
Stages of an HIV Infection
Opportunistic infections that kill most AIDS patients:
Bacterial pneumonia
Kaposi’s sarcoma
Yeast infections
Pneumonia
Toxoplasmosis of the brain

34. Reproduction of the Retrovirus HIV

35. 21.5 Disorders of the Reproductive System (STD’s)
Treatments for HIV Infection
Three Classes of Antiretroviral Drugs
Reverse transcriptase inhibitors
Protease inhibitors
Fusion inhibitors
Patients are usually given multiple drugs
Highly active antiretroviral therapy (HAART)
Antiretroviral drugs slow the progression of AIDS

36. 21.5 Disorders of the Reproductive System (STD’s)
Treatments for HIV Infection
HIV Vaccines
Obstacles to making an HIV vaccine include:
There are many strains of HIV
HIV mutates rapidly
HIV “hides” inside cells
Current research includes:
Recombinant vaccines
Inserting a piece of DNA encoding an HIV protein into another organism
Targeting the gp120 protein

37. 21.5 Disorders of the Reproductive System (STD’s)
Genital Herpes
Two types of Herpes Simplex Virus
Type 1: Colds sores and blisters (oral)
Type 2: Genital herpes
Crossover infections can occur
Symptoms
Tingling, itching occur first
Then blisters appear ( days later)
Fever, painful urination, swollen lymph nodes
Later, the virus lies dormant
May be reactivated by environmental factors
Infection of newborn babies can occur with serious health issues

38. 21.5 Disorders of the Reproductive System (STD’s)
Human Papillomaviruses (HPV)
Cause genital warts
Newborns can be infected
Some HPV’s can cause cervical cancer
Teenagers who have had multiple sex partners are particularly susceptible to HPV infection
No cure, treatments include removal of the warts by freezing, burning, acids, or lasers.
A vaccine is available, however it offers no protection to already infected individuals

39. 21.5 Disorders of the Reproductive System (STD’s)
Hepatitis B
Highly contagious
About 50% of infected people have symptoms that include: fever, headache, nausea, muscle aches, abdominal pain, jaundice
Can lead to liver failure
Vaccination with HBV vaccine can prevent infection

40. 21.5 Disorders of the Reproductive System (STD’s)
Chlamydia
Caused by bacterium Chlamydia trachomitis
More new chlamydial infections diagnosed than any other STD
5 times as many women as men are diagnosed
Probably reflects a decrease in males seeking medical attention
Mild lower urinary tract signs are common-painful urination, burning, mucus discharge
Can spread to prostate and epididymis in men
Can lead to pelvic inflammatory disease in women
Babies born to infected women may develop pneumonia and ocular infections
Treatment is with antibiotics

41. 21.5 Disorders of the Reproductive System (STD’s)
Gonorrhea
Caused by bacterium Neisseria gonorrheoae
Males: painful urinations, greenish-yellow discharge
Females: often no symptoms until pelvic inflammatory disease develops
The bacteria can spread to the throat (via oral sex) or other body parts that may be in contact direct or indirectly with sexual organs
Treatment for gonorrhea is antibiotic therapy

42. 21.5 Disorders of the Reproductive System (STD’s)
Syphilis
Caused by the bacterium Treponema pallidum
Three stages of disease
Primary stage: hard sore called a chancre at the point of infection
Secondary stage: non-itchy rash, hair loss, gray patches on mucous membranes
Tertiary stage: weakening of arterial walls (aneurysms), psychological disturbances, large ulcers on skin
Congenital syphilis- crosses placenta and causes fetal blindness and malformations
Treatment for syphilis is penicillin

43. Syphilis

44. 21.5 Disorders of the Reproductive System
In Males
Erectile Dysfunction (impotence)
Inability to produce or maintain an erection
Causes may include diseases, medications, alcohol consumption, and psychological factors.
Drugs that increase blood flow to the penis are a common treatment.

45. 21.5 Disorders of the Reproductive System (Males)
Disorders of the Prostate
Benign Prostatic Hyperplasia (BPH)
Enlargement of the Prostate
May constrict the urethra resulting in bladder or kidney damage
Treated with medications and/or surgery
Cancer of the Prostate
Most common diagnosed cancer in American males
Treatable if detected early

46. Benign Prostatic Hyperplasia

47. 21.5 Disorders of the Reproductive System (Males)
Testicular Cancer
Most common cancer in males aged
Highly treatable if detected early
Treatments may include surgery, chemotherapy and radiation
Self examinations are highly recommended

48. 21.5 Disorders of the Reproductive System (Females)
Endometriosis
Presence of endometrial tissue outside of the uterine cavity
Pain, abnormal menstrual cycles and infertility may result
Treatments include pain management, drugs, and surgery

49. 21.5 Disorders of the Reproductive System (Females)
Ovarian Cancer
Typically occurs in women over the age of 40
50% five-year survival rate
Sometimes described as “silent” because obvious signs or symptoms may not appear until the cancer is in later stages
Treatments include surgery, chemotherapy and radiation
Women who have not had children are at a higher risk

50. 21.5 Disorders of the Reproductive System (Females)
Disorders of Menstruation
Too little bleeding
May indicate a problem with the hypothalamus or pituitary gland
Too much bleeding
May be caused by STD’s, medications, or problems with blood clotting
Dysmenorrhea (painful menstruation)
Half of all women may experience this
May be caused by high level of prostaglandins, endometriosis, or ovarian cysts

51. 21.5 Disorders of the Reproductive System (Females)
Disorders of Menstruation
Premenstrual Syndrome (PMS)
Characteristics include mood swings, headaches, joint pains, digestive upsets, and sore breasts.

52. 21.5 Disorders of the Reproductive System (Infertility)
Infertility is the failure to conceive after one year of regular, unprotected intercourse
15% of couples are infertile
40% due to male, 40% due to female, 20% due to both
Causes
Low sperm count or sperm abnormalities
Sedentary life style, smoking, alcohol consumption all contribute
Body weight in women
Obesity is linked to ovulation failure
Pelvic inflammatory disease in women (blocks oviducts)
Endometriosis

53. 21.5 Disorders of the Reproductive System (Infertility)
Assisted Reproductive Technologies (ART)
Artificial Insemination by Donor (AID)
Sperm are placed in the vagina
Donor may be the woman’s partner or a donor
Variation- intrauterine insemination (IUI)- uterus is prepared by administration of fertility drugs and sperm are placed directly in the uterus
In Vitro Fertilization (IVF)
Immature eggs are harvested and maturity occurs in glassware
Sperm are added and fertilization takes place
Embryos are then implanted
Embryo’s can be tested for genetic diseases

54. 21.5 Disorders of the Reproductive System (Infertility)
Assisted Reproductive Technologies (ART)
Gamete Intrafallopian Transfer (GIFT)
Eggs and sperm are harvested and then placed in the oviducts immediately after they have been combined
Can also wait until zygotes form and then these are placed in the oviducts
Surrogate Mothers
Embryos from a couple are implanted into another woman for development to occur
Intracytoplasmic Sperm Injection (ICSI)
A single sperm is injected into an egg and then placed in the uterus or oviduct