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48 terms

Chapter 4: Male Anatomy & Physiology

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Penis
A male sexual organ consisting of the internal root and external shaft and glans.
Cavernous bodies
The structures in the shaft of the penis that engorge with blood during sexual arousal.
Root
The portion of the penis that extends internally into the pelvic cavity.
Glans
The head of the penis; it is richly endowed with nerve endings.
Shaft
The length of the penis between the glans and the body.
Foreskin (Prepuce)
A covering of skin over the penile glans.
Corona
The rim of the penile glans.
Frenulum
A highly sensitive think strip of skin that connects the glans to the shaft on the underside of the penis.
Scrotum
The pouch of skin of the external male genitals that encloses the testes.
Testis/Testicle
Male gonad inside the scrotum that produces sperm and sex hormones.
Spermatic Cord
A cord attached to the testis that contains the vas deferens, blood vessels, nerves, and cremasteric muscle fibers.
Sperm are produced in ?
Seminiferous tubules (thin, coiled structures in the testes)
Intersitial Cells
Cells located between the seminiferous tubules that are the major source of androgen in males.
Cryptochidism
A condition in which the testes fail to descend from the abdominal cavity to the scrotal sac.
What happens to the testicles what the environment is hot.
heat causes the scrotal skin to relax and the testes to descend.
3 Risks associated with Cryptorchidism?
1. Testicular Cancer
2. Infertility
3. Inguinal Hernias
Which testicle hangs lower?
The left hangs lower (because the left spermatic cord is generally lower than the right testis.
2 Structures within the testicles that are the site of sperm production.
1. Seminiferous Tubules
2. Epididymis
structure that serves as the site for storage and maturation of sperm.
Epididymus
What structure is cut during a vasectomy?
Vas Deferens
Seminiferous Tubules
Thin, coiled structures in the testes in which sperm are produced.
Epididymis
The structure along the back of each testis in which sperm maturation occurs.
Vas Deferens
A sperm-carrying tube that begins at the testis and ends at the urethra
Urethra
The tube through which urine passes from the bladder to the outside of the body
3 Structures that supply the fluid portion of semen.
1. Seminal Vesicles (provides most fluid)
2. Prostate Gland
3. Cowper's Glands
Seminal Vesicles
Small glands adjacent to the terminals of the vas deferens that secrete an alkaline fluid (conductive to sperm motility) that constitutes the greatest portion of the volume of seminal fluid released during ejaculation.
Prostate Gland
A gland located at the base of the bladder that produces about 30% of the seminal fluid released during ejaculation.
Cowper's Glands
Two pea-sized glands located alongside the base of the urethra in the male that secrete an alkaline fluid during sexual arousal.
Ejaculatory Duct
Two short ducts located within the prostate gland.
What structure provides that major portion of the seminal fluid in semen.
Seminal Vesicals
Smegma
A cheesy substance of glandular secretions and skin cells that sometimes accumulates under the foreskin of the penis or hood of the clitorus.
Urology
The medical specialty dealing with reproductive health and genital diseases of the male and urinary tract diseases in both sexes.
Typical range for the number of sperm found in the semen of a single ejaculation
200-500 Million
Average volume of seminal fluid produced by a man as a result of ejaculation
Roughly 1 teaspoon on average
What is the physiologic process that causes an erection?
When a male becomes sexually excited, the nervous system sends out messages that cause expansion of the arteries leading to the 3 erectile cylinders (cavernous bodies-2, 1 spongy body) in the penis. As a result, the rate of blood flow into these parallel cylinders increases rapidly. Because blood flowing out of the penis through veins cannot keep up with the inflow, it accumulat3es in the spongelike tissues of the erectile cylinders, causing erection. The penis remains erect until the messages from the nervous system stop and the inflow of blood returns to normal.
2 Stages of Ejaculation
1. Emission phase
2. Expulsion Phase
Emisson Phase
The first stage of male orgasm (ejaculation), in which the semnial fluid is gathered in the uretheral bulb.
Expulsion Phase
The second stage of male orgasm (ejaculation), during which the semen is expelled from the penis by muscular contractions.
Where does the semen go during retrograde ejaculation?
into the bladder
Wet Dreams AKA
Nocturnal Emissions AKA
The purpose of for the sugar secreted by the seminal vesicles.
seems to contribute to sperm nutrition and motility.
3 adverse conditions that occur less frequently in circumcised males.
1. Childhood urinary tract infections
2. adult penile cancer
3. genital wart infections
4. increased protection against HIV, the virus that causes AIDS
3 arguments that have been raised against routine circumcision.
1. the foreskin could serve some important function yet to be determined.
2. some investigators have expressed concern that sexual function may be altered by excising the foreskin
3. traumatic for a newborn and invites possible surgical complications.
age group that has the highest incidence of penile cancer.
over the age of 50
age group that has the highest incidence of testicular cancer.
20 to 35
condition that occurs in 50% of men aged 50-70 and causes problems with urine flow.
Benign Prostatic Hyperplasia
Digital Rectal Examination (DRE)
Test used to screen for prostate cancer.
Prostate Specific Antigen (PSA)
Test used to screen for prostate cancer. detectable by a blood test