HUMAN SEXUALITY

Chapter Five:Male Sexual Anatomy and Physiology

Sexual Anatomy

Male Sexual Functions

Some Concerns About Sexual Functioning

Male Genital Health Concerns

3 cylinders of spongy tissue

(2 cavernous bodies & 1 spongy body)

regions of the penis:

root (inward projection),

shaft (external portion minus the head),

glans (head)

circumcision: removal of foreskin

areas most sensitive to stimulation:

corona

frenulum

coronal papillae

(hirsutes papillaris)

(pearly penile papules)

small sebaceous glands and hair follicles on penis

multiple sebaceous cysts of the scrotum

(steatocystoma multiplex)

A Colour Atlas of Sexually Transmitted Diseases

scrotal sac: loose pouch of skin

- outpocket of abdominal wall in groin area

testis (pl. testes): produce sperm & hormones

cremasteric muscle

pulls testes upward

tunica dartos contracts with cold & arousal

vas deferens

sperm-carrying tube

testis

left usually lower than right

varicocele

Clinical Diagnosis 4^th ed. © Anne Cavanaugh Judge et al. p.330

testes produce

sperm & hormones

testes descend

from abdomen

into scrotum

via inguinal canal

picture from: the CIBA collection of medical illustrations Vol. 2

Frank H. Netter, MD

cryptorchidism

undescended testes

(3-4% newborn boys)

infertility

hernia

testicular cancer

heat impairs sperm production

picture from: the CIBA collection of medical illustrations Vol. 2

Frank H. Netter, MD

seminiferous tubules

produce sperm

from puberty to death

interstitial cells (Leydig cells)

produce androgens

epididymis

sperm are stored

and undergo maturation

vas deferens

long thin duct carrying sperm from the epididymis

(vasectomy = transection of vas)

seminal vesicles

secrete

alkaline fluid

rich in fructose through

excretory ducts into

ejaculatory duct

prostate gland

thin alkaline fluid

Cowper’s glands

(bulbourethral glands)

slippery

mucus-like droplet

during arousal

(“pre-cum”)

semen (seminal fluid)

fluid from

seminal vesicles

prostate

Cowper’s glands

(approximately 1 tsp / ejaculation)

sperm

200-500 million

(1% of total volume)

semen (seminal fluid)

chemicals

ascorbic & citric acids

water, enzymes, fructose,

phosphate & bicarbonate buffers,

other non-hazardous chemicals

may contain HIV virus

in infected persons

sexual excitement causes nervous system to send messages

expansion of arteries leading to erectile tissues occurs

penis remains erect until blood flow returns to normal

capacity for erection present at birth

nighttime erections occur during REM sleep

triggers for erections can be nonsexual (e.g. bike riding,

lifting heavy weights, straining during defecation etc.)

ejaculation = the process whereby semen is expelled through the penis to the outside of the body

ejaculation - like erection - is basically a spinal reflex

stimulation builds up neural excitation

which triggers the internal events

ejaculation and orgasm are not the same

pre-pubertal boys may have dry orgasms

men with multiple orgasms

may ejaculate only with the first (or occasionally the last)

Emission phase:

various secretions are forced into the urethral bulb

Expulsion phase:

semen is expelled by strong, rhythmic contractions

retrograde ejaculation

semen is expelled into bladder instead of out of the penis

nocturnal emissions “wet dreams”

involuntary ejaculation during sleep

PENIS SIZE

the greatest sensitivity in the vaginal canal

is concentrated in its outer portion

some women find deep penetration painful especially if it is also vigorous

Raratonga & the Cook Islands

lonely planet travel survival kit

3rd edition 1994, p160

Tony Wheeler & Nancy Keller

The circumcised penis

Our Sexuality 8^th edition p.131

Robert Crooks & Karla Baur

Human Sexuality 5^th edition p.113

Rathus, Nevid, and Fichner-Rathus

the uncircumcised penis

Human Sexuality 5^th edition p.113

Rathus, Nevid, and Fichner-Rathus

Our Sexuality 8^th edition p.131

Robert Crooks & Karla Baur

Who is Circumcised?

Source: E.O.Laumann et. al., (1997, April 2)

“Circumcision in the U.S.: Prevalence, Prophylactic Effects, and Sexual Practice.” The Journal of the American Medical Association, 227, pp. 1052-1057.

CIRCUMCISION: the surgical removal of the foreskin

performed on the majority of newborn male infants

before they leave the hospital (in the United States)

phimosis

the opening is too small to allow retraction of the prepuce

A Colour Atlas of Sexually Transmitted Diseases p.11

prepuce retractable by age 3 in 90% of uncircumcised males

Nelson Textbook of Pediatrics 15^th edition p.1547

congenital adhesions should be broken early in childhood

The CIBA Collection of Medical Illustrations Volume 2: Reproductive System p.32

retracted prepuce

A Colour Atlas of Sexually Transmitted Diseases

paraphimosis

swollen foreskin cannot return to normal position

risks of circumcision

undiagnosed abnormalities or illnesses may worsen

e.g.. bleeding disorders

risks of the procedure itself:

bleeding, local infection, partial or complete penile amputation, degloving injuries, urethrocutaneous fistulas, formation of skin bridges, staphylococcal scalded skin syndrome, meatitis, meatal ulcer, meatal stenosis, death (3 cases between 1954 and 1991), pain, complications of anesthesia (local anesthesia complications are mainly hematoma and local skin necrosis)

from: Fact sheet for Physicians Regarding Neonatal Circumcision

American Family Physician August 1995 pp523-526

benefits of circumcision

60,000 cases of penile cancer in the U.S. since 1930

fewer than 10 in circumcised men

(59,990+ cases in uncircumcised men)

there MIGHT be an increase in

squamous cell carcinoma of the cervix

in female partners of uncircumsized men

benefits of circumcision (continued)

circumcised men MIGHT

have a decreased risk of contracting the HIV virus

and maybe other STDs

circumcised boys are

10-39 times less likely than noncircumcised boys

to have urinary tract infections during infancy

(possible complications:

bacteremia, meningitis, renal failure, death.

Also: renal scarring, hypertension and renal insufficiency requiring dialysis or transplantation.)

circumcision and sexual response

Masters and Johnson found

no differences in sexual responsiveness

between circumcised and uncircumcised males

Some males have undergone circumcision later in life and could compare sex before circumcision with sex after.

Some of these men found no difference.

Some found a decrease in sensitivity of the glans.

smegma

A Colour Atlas of Sexually Transmitted Diseases. Anthony Wisdom 1992 p15

Wash the penis regularly with soap and water (at least daily).

Washing the genitals before and after sex may decrease STDs.

Build up of secretions mixed with dead skin cells results in the formation of a cheesy substance called smegma.

Smegma may be associated with odor, irritation and a breeding ground for infection.

do not use a “cock ring” which can destroy penile tissue

by cutting off the blood supply

insertion of the penis into rigid mechanical apertures such as bottles, pipes, metal rings, etc., may result in strangulation

The CIBA Collection of Medical Illustrations Volume 2: Reproductive System p.32

to avoid a fractured penis:

do not forcefully hit or bend an erect penis

(or allow a partner to do so)

The CIBA Collection of Medical Illustrations Volume 2: Reproductive System p.34

do not masturbate using a vacuum cleaner

which can result in severe injuries

penile cancer

A Colour Atlas of Sexually

Transmitted Diseases. Anthony Wisdom

penile cancer

1300 men /year in the US

develop penile cancer

5 year survival rates:

overall: 50%

early diagnosis: 90%

penile cancer risk factors:

age over 50

history of multiple sexual partners and STDs

poor genital hygiene

being uncircumcised

long smoking history

(risk increase from 1/100,000 to 1/600)

Peyronie’s disease

caused by fibrotic plaques of the corpora cavernosa

usually occur after age 45

Mosby’s Guide to Physical Examination

4^th edition Seidel, Ball, Dains & Benedict

Physical Examination and Health Assessment 3^rd edition

Peyronie’s disease

fibrotic plaques of the corpora cavernosa

can be removed surgically

The CIBA Collection of Medical Illustrations Volume 2: Reproductive System p.33

priapism

a persistent painful erection

Atlas of Pediatric Physical Diagnosis 2^nd edition Basil J. Zitelli & Holly W. Davis editors p. 14.13

The CIBA Collection of Medical Illustrations Volume 2: Reproductive System p.32

testicular cancer

1% of all cancers in males

most common cancer in males ages 15 - 34

no symptoms in early stages

(other than a mass within the testicle)

survival rate better than 90%

if detected early and treated

Testicular Self Exam (to be done at least monthly):

Roll each testicle between your thumb and first three fingers until you have felt the entire surface.

Patient Care. October 30 1992. p79

the testicles should feel round and smooth,

like hard-boiled eggs

look for: lumps, irregularities, change in testicle size,

pain in testicle, dragging or heavy sensation.

Examine yourself monthly

Examine yourself after a warm shower when the scrotum is most relaxed

Using both hands, gently roll each testis between the thumb and fingers

Lance Armstrong

It’s Not About the Bike:

My Journey Back to Life

a story about overcoming advanced testicular cancer

prostatitis

enlarged and/or inflamed prostate, often infected

occurs at any age

treatment: antibiotics

Treating Prostate Problems

prostatitis symptoms

pain in pelvic area

pain at base of penis

lower abdominal ache

backache

aching testicles

urgent frequent urination burning while urinating

cloudy discharge

painful erections

painful ejaculations

reduced sexual interest

Treating Prostate Problems

Benign Prostatic Hyperplasia (BPH)

50% of men between 50-60 years old

Treating Prostate Problems

Thickened bladder walls can’t contract and release urine normally.

Pressure from a full bladder can cause leaking (incontinence)

an enlarged prostate usually causes urinary difficulties

Treating Prostate Problems

TURP (Trans Urethral Resection of Prostate)

The CIBA Collection of Medical Illustrations Volume 2: Reproductive System p.61

prostate cancer

10% of men in the U.S. will develop prostate cancer

second leading cause of cancer death among US males

(after lung cancer)

risk factors:

old age

family history of prostate cancer

black race

smoking

prior history of sexually transmitted diseases

diet high in saturated fats

prostate cancer

diagnosis

Digital Rectal Exam (DRE).

blood test:

Prostate Specific Antigen (PSA).

PSA may also be high in BPH

(Benign Prostatic Hyperplasia)

American Cancer Society recommendations

DRE every year for all males and females age 40+

PSA for males 50+

or 40+ for black males or family history

digital rectal exam examine the prostate

for evidence of cancer

or other abnormalities

Physical Examination and

Health Assessment 3rd edition

Carolyn Jarvis

pp789 & 796

DRE normal

PSA: <4 4-10 >10ng/ml

CA Risk: 2% 15% 35%

DRE abnormal

PSA: <4 4-10 >10ng/ml

CA Risk: 10% 35% 67%

Cecil Textbook of Medicine 20th edition p1344

Rudolph Giuliani

diagnosed with prostate cancer in April 2000

received radioactive seed implants in September 2000

Photo: The American Spirit:

Meeting the Challenge of September 11

LIFE Books page 92

prostate cancer treatment options

“nerve sparing” surgery

external-beam radiation

highly targeted proton radiation

radioactive seed implants

hormone treatments

combination treatments

“watchful waiting”

patients with moderately differentiated tumors

who are initially untreated:

40-50% chance of metastatic disease

within 10 years

patients with moderately differentiated tumors

who are treated by radical prostatectomy:

<10% chance of metastatic disease

within 10 years

Cecil Textbook of Medicine 20th edition p1345

hernia

technique of examination for inguinal hernia