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AP2-LabUnit-10MaleReproductiveSystem.ppt
Human Anatomy and Physiology II Lab
The Male System
BIOL 222L
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Dr. Joseph Orban
Distinguished Professor and
Director of Biomedical Research Development
Southern University at Shreveport Louisiana
318-670-9360
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Male Reproductive System
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Male Inguinal and Scrotal Region
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Anatomy of Penis
Fig. 27.12 a and b
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Sexual Response
- Parasympathetic signals produce an erection with direct stimulation of penis or perineal organs
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Spermatozoon
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Travel Pathway for Sperms
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How Erection Occurs
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- Sexual stimulation triggers nitric oxide secretion which activates the enzyme guanylate cyclase.
- Guanylate cyclase produces cyclic guanosine monophosphate (cGMP).
- cGMP relaxes smooth muscles of the deep arteries and lacunae of the corporal carvenosa.
- This results in increased blood to erectile tissues leading to erection.
- Erection goes down when cMGP is broken down by the enzyme phosphodiesterase type 5.
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Male Reproductive Disorders
- Erectile Dysfunction - Inability to maintain an erection. Causes may include aging, decline in testosterone level, disease, medications, depression, fear of failure.
- Infertility – Inability to fertilize an egg because of low sperm count, poor sperm motility or high percentage of deformed sperm (no head, two heads, defective tails).
- Penile Cancer – Accounts for 1% of male cancers in US.
- Testicular Cancer – Common in men 15-34 yrs.
- Varicocele – Abnormal dilation of veins of the spermatic cord caused by absence or imcompetence of venous valves. Occurs in 10% of men in US.
- Hypospadias – Defect in which the urethra opens on the ventral side or base of the penis instead of the tip.
- Breast Cancer – Accounts for 0.2% of male cancers in US. The ratio of Male to female breast cancer is 1:175.
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Drugs for Treatment of Erectile Dysfunction
- Sildenafil (Viagra)
- Vardenafil (Levitra)
- Tadalafil (Cialis)
- How they work: These drugs are in the family of phoshodiesterase inhibitors. They work to slow down the action of phosphodiesterase type 5 thus prolonging the action of cyclic guanosine monophosphate which relaxes smooth muscles, increases blood flow to erectile tissues and brings about erection.
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How Viagra Prolongs Erection
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Methods of Contraception
Contraception is a procedure or device intended to prevent pregnancy
Behavioral Methods
Abstinence – complete avoidance of sex or avoidance 7 days before ovulation and 2 days after ovulation. Has 25 % failure rate due to failed willpower.
Barrier and Spermicides
Male condom – placed over penis to trap sperms
Female condom – placed over cervix and external genitalia
Diaphragm – placed over cervix
Sponge with spermicide – inserted before sex
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Methods of Contraception
Hormonal Methods
Birth control pills – estrogen and progesterone
Medroxyprogesterone – synthethic progesterone injected 2-4 times a year
Surgical Methods
Tubal ligation – uterine tubes blocked or cut
Vasectomy – cutting of ductus deference
Intrauterine Device (IUD) – inserted into uterus and left in place for 1-4 years
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Contraceptive Devices
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Sexually Transmitted Diseases (STD)
Bacteria STD
Chlamydia – most common in US (3-5 million cases/yr). Caused by Chlamydia trachomatis. Incubation period 1-3 weeks. Symptoms include watery discharge from the urethra and pain in the testis or rectal or abdominal region
Gonorrhea – caused by the bacterium Neisseeria gonorrhoeae. Symptoms include pus discharge from penis or vagina, abdominal discomfort, genital pain, painful urination (dysuria), abdominal uterine bleeding.
Syphillis – caused by the bacterium Treponema pallidum. Incubation period is 2-6 weeks. Sypmtoms include ulcers called chancre appear on site of infection, skin rashes and eruptions, fever, joint pain and hair loss. Symptoms come and go for up to 5 years. Advanced stage of the disease leads to tertiary syphillis or neurosyphillis damaging blood vessels and heart valves, thickening of the meninges and lesions of the brain leading to paralysis and dementia
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Sexually Transmitted Diseases – Bacterial
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Gonorrhea – Caused by Neisseria gonorrhoeae
Syphilis – Caused by Treponema pallidum
Syphilis – Mouth patches
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Sexually Transmitted Diseases (STD)
Viral STD
Genital herpes – most common in US with 20-40 million people affected with 500,000 new cases per year. Caused by herpes virus type-2 or type-1. Symptoms include fever blisters of the mouth, red blisters on the penis, labia, vagina or cervix and sometimes blisters may appear on thighs and buttocks of either sex, watery discharge from penis or vagina.
Genital warts – caused by 60 or more viruses collectively called human papillomaviruses. In males, lesions appear on penis, perineum, or anus. In females, lesions appear in cervix, vagina wall, perineum or anus
Hepatitis B and C – inflammatory liver disease caused by hepatitis B and C viruses
HIV/AIDS – caused by retrovirus. Occurance is worldwide affceting over 40 million people. Affects all ages but mostly frequent in young people due to higher sexual activity.
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Sexually Transmitted Diseases – Viral
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Genital Herpes Simplex Caused by Herpes Simplex Virus Type-2
Genital Warts
Caused by Human Papillovirus
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