Male Anatomy Flashcards
External anatomy of the penis
Foreskin, glans, shaft, and root
Internal anatomy of the penis
Cavernous bodies (corpora cavernosa), spongy body (corpus
spongiosum), and penile urethra
Areas particularly responsive to stimulation in the penis
Corona: rim of penile glans
− Frenulum: highly sensitive thin strip of skin that connects the glans
to the shaft
Strengthening musculature around the penis
Kegel exercises can produce benefits
scrotum
Pouch of skin of external male genitals that encloses the testes
testis
male gonads that produce sperm and sex hormones
cryptorchidism
undescended testis
Seminiferous tubules
thin, coiled structures in the testes in which
sperm are produce
Epididymis
structure along the back of each testis in which sperm
maturation occurs
vas deferens
Sperm-carrying tube that begins at the testis and ends at the urethra
− Sperm held in the epididymis eventually drain into the vas
deferens
vasectomy
male sterilization procedure
− Involves removing a section from each vas deferens
seminal vesicles
− Small glands adjacent to terminals of vas deferens
Secrete an alkaline fluid (conducive to sperm motility) that
constitutes the greatest portion of volume of seminal fluid
released during ejaculation (70%)
prostate gland
− Gland located at the base of the bladder
− Produces about 30% of the seminal fluid released during
ejaculation
Cowper’s glands
− Pea-sized glands located alongside the urethra base
− Secretes alkaline fluid during sexual arousal
Semen (seminal fluid)
Volume is about one teaspoon
− 100 to 500 million sperm per ejaculation
Erection
Coordinated by autonomic nervous system
− Arteries leading to the three erectile cylinders in the penis expand
− Blood outflow cannot keep up with inflow
* Capacity for erection is present at birth
− Common for infant boys
Psychogenic and physiogenic erections
Inputs come simultaneously from both thoughts and physical
stimulation
Spinal reflex triggers two phases
− Emission: fluid gathered in urethral bulb
− Expulsion: semen is expelled
Retrograde ejaculation
Semen is expelled into the bladder
Nocturnal emission
Involuntary ejaculation during sleep
Concerns About Sexual Functioning
penis size
Genital retraction syndrome
Circumcision
penis size
− Seen as a symbol of virility
− Implication that bigger is better
− Erect penises show less variation than flaccid
− Matter of subjective preference
− Difficult to get accurate estimate of average penis size
Across studies, average erect penis just over 5 inches
− Phalloplasty: penile augmentation
Genital retraction syndrome
− Culture-bound phenomenon
− Male believes his penis is shrinking and retracting into his body
Circumcision
surgical removal of penis foreskin
− Pros: hygienic value and increased H IV protection
− Cons: possibility of unknown function, altered sexual function, and
trauma for newborn
− Rates of circumcisions vary widely around world
− American Academy of Pediatrics (A AP): moderate opposition
Benefits slightly outweigh risks
Data not significant to recommend routine procedure
The penis: health-care issues
Cleanliness: smegma and infections
− Infection transmission: condom usage
− Injuries: hazards of sexual gadgets and fractures during coitus
− Penile cancer: deadly if not diagnosed early
Testicular cancer
More common in young men (20 to 35 years old)
− Risk factors: smoking, family history, White race, and
cryptorchidism
− Symptoms: hard or irregular mass in testes, fever, groin ache,
heaviness in testis, tender breasts, painful fluid accumulation or
scrotum swelling
− Survival is greater than 90% if detected early
Prostate diseases
− Prostatitis: enlarged and inflamed prostate
− Benign prostatic hyperplasia: increased prostate gland size
− Prostate cancer: second leading cause of cancer death
Treatment options for prostate cancer: benefits must outweigh
risks
