MALE SEXUAL ANATOMY & PHYSIOLOGY

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)

[pictures of cavernous bodies & spongy body]

[more pictures of cavernous bodies & spongy body]

[another picture of cavernous bodies & spongy body]

regions of the penis

root (inward projection)

shaft (external portion minus the head)

glans (head)

[pictures of regions of the penis]

areas most sensitive to stimulation:

corona

frenulum

[pictures of corona and frenulum]

coronal papillae

(hirsutes papillaris)

(pearly penile papules)

[picture of coronal papillae]

circumcision:

removal of foreskin

[picture of foreskin]

small sebaceous glands and hair follicles on penis

[picture of foreskin that looks like it has exagerated “goose bumps”]

scrotal sac = loose pouch of skin

outpocket of abdominal wall in groin area

testis (plural = testes) – produce sperm & hormones

[pictures of scrotum and testes]

cremasteric muscle

pulls testes upward

tunica dartos

contracts with cold & arousal

[picture of cremasteric muscle and tunica dartos]

vas deferens

sperm-carrying tube

testis (testicle)

left usually lower than right

[picture of testicle and general location of vas deferens]

varicocele

[drawing and photo of varicocele]

testes produce

sperm & hormones

[drawing of internal structure of testicle and epididymis]

testes descend from abdomen into scrotum via inguinal canal

[picture of testicular descent pathway]

cryptorchidism

undescended testes

(3-4% newborn boys)

infertility

hernia

testicular cancer

heat impairs sperm production

[picture of testicular descent pathway]

seminiferous tubules

produce sperm from puberty to death

interstitial cells (Leydig cells)

produce androgens (such as testosterone)

[picture of seminiferous tubules]

seminiferous tubule

[electron microscope picture of cut through seminiferous tubule]

detail of seminiferous tubule

[light microscope picture of cut through seminiferous tubule

and line drawing of sperm in various stages of development]

epididymis

sperm are stored and undergo maturation

[picture of epididymis]

vas deferens

long thin tube carrying sperm from epididymis

vasectomy

= cutting of the vas (deferens)

[drawing of the vas deferens]

seminal vesicles

secrete alkaline fluid rich in fructose

through excretory ducts into ejaculatory duct

[picture of seminal vesicles]

prostate gland

thin alkaline fluid

[picture of prostate gland]

Cowper’s glands (bulbourethral glands)

slippery mucus-like droplet during arousal (“pre-cum”)

[picture of Cowper’s gland (bulbourethral gland]

[picture of sexual and reproductive organs in the male pelvis]

semen (seminal fluid)

fluid from

seminal vesicles

prostate

Cowper’s glands

(approximately 1 tsp / ejaculation)

sperm

200-500 million

(1% of total volume)

[picture of sperm]

semen (seminal fluid)

chemicals

ascorbic & citric acids

water, enzymes, fructose

phosphate & bicarbonate buffers

other non-hazardous chemicals

may contain HIV virus in infected persons

[picture of sperm]

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 (bike riding,

lifting heavy weights, straining during defecation etc.)

[pictures of a flaccid and an erect penis]

[picture of blood vessels inside a flaccid penis]

[picture of blood vessels inside an erect penis]

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

[picture of emission phase]

expulsion phase

semen is expelled by strong, rhythmic contractions

[picture of expulsion phase]

retrograde ejaculation

semen is expelled into bladder instead of out of the penis

nocturnal emissions “wet dreams”

involuntary ejaculation during sleep

[picture of path of semen movement during normal and retrograde ejaculation]

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

[picture of carved wooden statue with large penis]

[picture of painting of man with large penis]

the circumcised penis

[2 pictures of penises that have been circumcised]

the uncircumcised penis

[2 pictures of penises that have not been circumcised]

Intact adult penis

[line drawing showing external appearance of the penis]

Intact penis (hidden structures shown)

[line drawing showing structures within the intact penis]

uncircumcised penis

Erection begins [drawing]

Erection continues [drawing]

Erection complete [drawing]

circumcised penis

[drawing of flaccid penis]

[drawing of erect penis]

[photos of foreskin being pulled back by hand]

[photos of foreskin moving away from glans as a consequence of erection]

Who is Circumcised?

[bar graph illustrating cultural differences in circumcision rates with

highest circumcision rates among Jewish American men and

lowest circumcision rates among Latino American men]

circumcision = the surgical removal of the foreskin

performed on many newborn male infants

before they leave the hospital (in the United States)

[picture of steps in the circumcision procedure]

phimosis

the opening is too small to allow retraction of the prepuce

prepuce retractable by age 3 in 90% of uncircumcised males

[picture of phimosis]

congenital adhesions can be broken early in childhood

[picture of adhesions]

retracted prepuce

[picture of retracted prepuce]

paraphimosis

swollen foreskin cannot return to normal position

[photo of paraphimosis]

risks of circumcision

undiagnosed abnormalities or illnesses may worsen

example: bleeding disorders

risk 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)

alleged benefits of circumcision

60,000 cases of penile cancer in the US after 1930

fewer than 10 in circumcised men

(59,990+ cases in uncircumcised men)

Note:

in the years immediately following 1930

old men were more likely to be uncircumcised

young men were more likely to be circumcised

1437 US men will not get penile cancer

for every 1 US man who has penile cancer

80% of US men are circumcised

****************************

********************************************

1964 Danish men will not get penile cancer

for every 1 Danish man who has penile cancer

less than 1% of Danish men are circumcised

[graphical presentation of the data]

alleged benefits of circumcision (continued)

circumcised men are thought (by some people)

to have a decreased risk of contracting the HIV virus

and maybe other STDs

Where circumcision doesn’t prevent AIDS

Country % of men circumcised %HIV prevalence in

Adults Circumcised men Uncircumcised men

Burkina Faso 88 1.8 1.8 2.9

Cameroon 93 5.5 4.1 1.1

Cote d’Ivore 96 4.7 2.8 3.8

Ethiopia 91 1.4 0.9 1.1

Ghana 95 2.2 1.6 1.4

Kenya 83 6.7 3.0 12.6

Lesotho 49 23.5 22.8 15.2

Malawi 20 11.8 13.2 9.5

Rwanda 9 3.0 3.5 (2010 2.5) 2.1 (2010 2.2)

Swaziland 8.1 25.9 21.8 19.5

Tanzania 69 7.0 6.5 5.6

Uganda 25 6.4 3.8 5.6

Does circumcision protect?

[bar graphs of HIV% for different countries comparing circumcised men and uncircumcised men]

http://www.circumstitions.com/HIV.html#doesn’t

accessed 1/18/2014

alleged benefits of circumcision (continued)

circumcised boys are thought (by some people)

to have a decreased risk of

urinary tract infections (UTIs) during infancy

(possible complications of UTIs:

bacteremia, meningitis, high blood pressure, death

kidney damage requiring dialysis or transplantation)

one alternative hypothesis

many of the urinary tract infections in uncircumcised boys

may be caused by parents and doctors trying to retract

the foreskin when it is not ready to be retracted yet

the trauma caused to the penis by forcefully retracting

the foreskin of newborns or toddlers

and the increased manipulation of the penis

might increase the risk of infection

circumcision and sexual response

Masters and Johnson found

no difference 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

[picture of smegma]

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

[picture of strangulated penis]

to avoid a fractured penis

do not forcefully hit or bend an erect penis

(or allow a partner to do so)

[pictures of fractured penises)

do not masturbate using a vacuum cleaner

which can result in severe injuries

[pictures illustrating use of prescription medical device

using negative pressure (vacuum) to treat erectile dysfunction]

penile cancer

[3 photos of penile cancer]

penile cancer

1300 men / year in the US develop penile cancer

5 year survival rates

overall 50%

early diagnosis 90%

[2 photos of advanced metastatic penile cancer]

penile cancer risk factors

age over 50

history of multiple 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

[photos of two examples of Peyronie’s disease]

Peyronie’s disease

fibrotic plaques of the corpora cavernosa

can be removed surgically

[pictures of problem and surgical solution]

priapism

a persistent painful erection

[drawing and photo of priapism]

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 (TSE) (to be done at least monthly)

roll each testicle between your thumb and first three fingers

until you have felt the entire surface

[picture illustrating TSE technique]

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

[picture of normal testicle, and testicle with lump]

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.

[illustrations of testicular self exam]

Lance Armstrong

It’s Not About the Bike: My Journey Back to Life

A story about overcoming advanced testicular cancer

[pictures of Lance Armstrong and books by and about him]

prostatitis

enlarged and/or inflamed prostate, often infected

occurs at any age

treatment = antibiotics

[pictures of prostate and prostatitis]

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

[pictures of prostate and prostatitis]

Benign Prostatic Hyperplasia (BPH)

50% of men between 50-60 years old

[pictures of enlarged prostates]

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

[picture of thickened bladder walls]

Pressure from a full bladder can cause leaking (incontinence).

[picture of leaking urine]

an enlarged prostate usually causes urinary difficulties

TURP (Trans Urethral Resection of Prostate)

[picture of TURP procedure]

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 screening

Digital Rectal Exam (DRE) – finger test

Prostate Specific Antigen (PSA) - blood test

PSA may also be high in BPH

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

[pictures of exam technique and possible abnormal findings]

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%

Rudolph Giuliani

diagnosed with prostate cancer in April 2000

received radioactive seed implants in September 2000

[picture of Rudolph Giuliani]

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

hernia

[drawing of hernia]

technique of examination for inguinal hernia

[drawing of hernia exam procedure]