Bio 27: September 12, 2012

Chapter 3: Female Sexual Anatomy & PhysiologyChapter 4: Male Sexual Anatomy & Physiology

CHAPTER 3: FEMALE SEXUAL ANATOMY AND PHYSIOLOGY

Gynecological Health Concerns• Hysterectomy (removal of the uterus) or

oophorectomy (removal of the ovaries)– Used in cases of cancer of the cervix, uterus or ovaries– Hysterectomy is most frequently performed U.S.

operation (33% of women undergo by age 65)– Also used to treat fibroids (non-cancerous growths),

endometriosis, pelvic pain, and irregular bleeding – Hysterectomy may decrease sexual response in many

women; oophorectomy induces the same hormonal changes associated with menopause unless replacement hormones are taken

– More common in poor and less educated women

THE BREASTS

Breasts

• Breasts are a secondary sex characteristic: something other than genitals that distinguishes men and women

• Mammary glands produce milk after pregnancy

• Areola is darker area• Nipple is in center of

areola & has openings for milk

Cross-Section of Breast

Breast Health Problems

• Breast Lumps: can be detected by self exam– Cysts (fluid-filled sacs)– Fibroadenomas (solid, round, benign tumors)– Malignant tumor

• Breast cancer– Treatments: surgery, chemotherapy, radiation– Risk factors: age, hormones, smoking, family history– Reconstructive breast surgery– Early detection & treatment boosts survival

CHAPTER 4 MALE SEXUAL ANATOMY AND PHYSIOLOGY

Male genitalia are as diverse as female genitalia

The Penis

• Consists of nerves, blood vessels, fibrous tissue & spongy tissue; no bones!

• Interior portion of the penis is the root

• Head of the penis is called the glans; this is surrounded by a ridge called the corona

• Remainder of penis is the shaft

The Penis• Like the vagina, the penis

has 3 layers of tissue: 2 cavernous bodies, and 1 spongy body

• These fill with blood during sexual excitation, creating an erection

The foreskin & circumcision• The glans of the penis is

covered by a loose layer of skin called the foreskin

• Some cultures practice removal of the foreskin, usually in infant boys

Circumcision for health?• 1971: American Academy of

Pediatrics states that there is no medical benefit to circumcision

• 1989: AAP states that there are “potential benefits”

• 1999: AAP states that there are “insufficient data” to recommend circumcision

• 2012: AAP states that the health benefits of circumcision outweigh the risks

Circumcision: pros and consCons:• Complications can arise (rare)• Foreskin removal may cause trauma from pain• Reduced sexual enjoyment (?-controversial)• Cannot be easily reversedPros:• Circumcision reduces rates of sexually transmitted diseases,

including HIV• Also reduces risk of urinary tract and bladder infections, and

of cancerFor many parents, medical concerns are secondary to religious/cultural or appearance concerns

The scrotum• Scrotum: pouch with two

chambers for each of two testicles or testes

• Has two layers:– skin layer: skin is darker

than on rest of body and becomes covered with hair at puberty; analogous to labia majora in women

– tunica dartos: muscle layer• Pulls sac closer to body

in cold temperatures

The scrotum and testes• Testes are the equivalent of

the ovaries in females• Make sperm and also

testosterone and other hormones

• Spermatic cord holds each testis

• Also contains the vas deferens, which delivers sperm from the testes to the penis (a vasectomy is surgical closing off of the vas deferens)

The testes• Male gonads (testes) are

outside the body unlike female gonads (ovaries)

• This is true for most but not all mammals

• Sperm survive yet at a temp slightly cooler than body temperature

Castration• Castration: surgical removal of the testes;

drastically decreases testosterone and male sexual behavior; destroys fertility

• Eunuchs: men or boys who have undergone castration

• Castration has been used as punishment; many cultures have castrated slaves or servants

• Castration before puberty was used until the 19th century in Europe to preserve the singing voices of boys; some boys’ voices still underwent changes

The testes: function

• Seminiferous tubules: site of sperm production

• Sperm travel from there to the epididymis, where they are stored

• Interstitial cells between seminiferous tubules make most of the body’s testosterone

Testicular problems: Cryptorchidism

• In male fetuses, testes develop inside the abdominal cavity and usually descend into the scrotum by birth

• Cryptorchidism: failure of the testes to descend; affects 3–5% of male infants

• Can result in infertility and increased risk of cancer, but can be treated very effectively with hormones and/or surgery

Testicular problems: testicular cancer• Most common cancer in

males age 20–35• Accounts for 1–2% of all

cancers in males• Risk factors include smoking,

family history, white race, and cryptorchidism

• Usually shows up as a mass in one testicle, can be detected by male genital self-exam (described in book)

• Early detection results in greater than 90% survival

The prostate• The prostate makes seminal

fluid, the fluid in which sperm leave the body

• Seminal fluid + sperm = semen

• 50% of men over age 60 and 90% of men over age 90 experience benign prostatic hyperplasia or an enlarged prostate

• This can cause urinary issues!

Prostate cancer• Second most common cancer in American

males (after skin cancer)• Risk factors are: old age, family history, high-

fat diet, African-American race• 218,000 U.S. men are diagnosed each year

and 28,000 U.S. men die from it each year• Can be detected with a blood test (somewhat

controversial) or with a physical examination (digital rectal examination)

“Male and female reproductive anatomy shows more similarities than differences”

How strongly do you agree or disagree with this statement? Support your answer with specific evidence.

1 2 3 4 5

strongly disagree

somewhat disagree

neutral somewhat agree

strongly agree