Learning Objectives

These are some of the topics we will discuss below:

-Anatomical structure of the males reproductive system.
-Components of the testes.
-Process and Analysis of spermatogenesis

Notes, Pictures & Videos

In the male reproductive system the main gonads are called the "testes".


LINKS

Cadaver Breakdown Of The Male Reproductive Sysyetm
Inside The Male Cadaver Extrenal Genitalia
Cadver Discetion showing the path of the semen
Cadver Disection Of Testies
Scrotum-the ideal temperature for producing and storing sperm is about 3 degrees Celsius lower than body temperature. The scrotum is a skin covered sac that lies between the thighs and provides a cooler environment needed for normal sperm and development and maturation. It contains a ridge like seam at the midline called the "raphe".

Testes- relatively small and oval organ housed within the scrotum. The testes produce sperm and androgen's( male sex hormones). Each testis is subdivided into about 250 "lobules". The most common androgen is called "testosterone". Androgens cause males to develop male characteristics at puberty. The testes receive blood through the gonadal (testicular) arteries that arise from the abdominal aorta. Venous blood is drained by the gonadal (testicular) veins. Inflammation of the testis is called "orchitis". How does testosterone affect male fertility ? The Role of Testosterone
The main male sex hormone is testosterone and this is made by the testicles, starting at puberty. Testosterone is produced by specialized cells in the testis called the Leydig cells. These are stimulated to release testosterone in response to the LH signal from the pituitary . LH is luteinizing hormone - the same hormone found in women.

Semen- is fluid from the accessory glands that combines with sperm from the testes. When released during intercourse, semen is called the ejaculate and is normally 3 to 5 milliliters in volume and contains approximately 200 to 500 million spermatozoa. Though actual sperm counts can vary the seminal fluid volume will stay the same.

Similarities between the male and female reproductive system.
-The gland of the clitoris is homologous to the tip of the penis.
-The hood of the clitoris is homologous to the foreskin(prepuce) in the penis.
-The labia majora is homologous to the scrotum.

Case Study

Enlarged Prostate (BPH):

The most common prostate problem for men over 50 is prostate enlargement. By age 60, over one-half of men have BPH; by age 85, the number climbs to 90%

Symptoms of enlarged prostate can include:

• A weak or slow urinary stream
• A feeling of incomplete bladder emptying
• Difficulty starting urination
• Frequent urination
• Urgency to urinate
• Getting up frequently at night to urinate
• A urinary stream that starts and stops
• Straining to urinate

Information on treatments
An enlarged prostate is due to inflammation of the urethra.
-The most common treatment for an inflame urethra is TURP,
Transurethral Resection of the Prostate, a tool that is inserted into the penis to open up prostate.

In the News

A New, Nearly Foolproof Circumcision Device! This device (invented in Utah!) may significantly reduce complications from circumcisions. The company is planning on making an adult-version of the device, as there is high demand among men in Africa for this procedure (it reduces the risk of spreading HIV to female partners).

Glossary

Circumcision-is the surgical removal of the foreskin or prepuce.
Semen-fluid from the accessory glands combines with sperm and testes.
Ejaculation-process by which semen is expelled from the penis.
Prostate Gland-is a compact encapsulated organ that is about the same shape and size as a walnut.
Penis-forms the external genitalia in males. The move able portion of the penis is called the "body" or "shaft". The tip is called the "glans".
Epididymis-is a comma shaped structure composed of an internal duct and an external covering of connective tissue. It's "head" lies on the superior surface of the testis while the " body" and "tail" are posterior to the testis. Internally the epididymis contains a long convoluted duct of the epididymis which is approximately 4 to 5 meters in length.
Ductus deferens-sperm enter from the epididymis. Ductus deferens is also called "vas deferens". It is a thick walled tube that ravels within the spermatic cord, through the inguinal canal, and within the pelvic cavity before it nears the prostate gland at the base of the bladder. It is composed of an inner "mucosa" that is lined with ciliated epithelium, a middle "muscularis" that contains several layers of smooth muscle that contract to help move sperm cells through the ductus deferens, and an outer "adventitia".
Erection-venous spaces become engorged with blood and the erectile bodies become rigid.
Seminiferous tubules-produce millions of sperm cells every day.
Spermatogenesis-production of sperm.
Sustentacular cells-assist with sperm development, provide a protective environment, and create a barrier between sperm cells and the circulatory system.
Nocturnal emissions-are monthly episodes where the males reproductive system encounters an urge to ejaculate its contents.
Interstitial cells-produce males hormones (androgens).
Androgens-cause males to develop male characteristics.
Orchitis-inflammation of one or both testes.
Bulbourethral gland-lubricates the head of the penis.
Seminal vesicle-neutralizes the secretions of the vagina.
Gonorrhea-inflammation of the urethra.
Proctologis-specialist in the males reproductive system.
Transurethral resection of the prostate(TURP)-a device inserted in the males penis to help with an inflame urethra.
Hypertrophy-enlarge urethra.

Connections to other body systems

A Link To Some Great Videos About Male Anatomty
Connection to the circulatory system-the right testicular vein drains directly into the inferior vena cava.
-the left testicular vein drains directly into the left renal vein.

Review Questions

1. What is the ridge like seam at the midline of the scrotum called?
a. Raphe
b. Scrotum
c. Urethra
d. Testis

2. Inflammation of the testis is called what?
a. Orchitis
b. Otitis media
c. Testisitis
d. Rapheitis

3. The "ductus deferens" is also called what?
a. vas deferens
b. spermatic cord
c. inguinal canal
d. epididymis

4. How long is the ejaculatory duct?
a. 1 to 2 centimeters
b. 3 to 4 centimeters
c. 5 to 6 centimeters
d. 7 to 8 centimeters

5. The prostate gland is about the same size and shape as a _______?
a. grape
b. walnut
c. tomato
d. olive

6. What is the process called when semen is expelled?
a. erectile dysfunction
b. ejaculation
c. ejaculatory
d. erection

7. What is the tip of the penis called?
a. glans
b. body
c. shaft
d. end of the penis

8. when erection takes place in the penis where does the most blood go into?
a. scrotum
b. Corpora cavernosa
c. corpora spongiosum
d. epididymis

9. Each testis is subdivided into about 250 'lobules'. Each lobule contains up to 4 extremely convoluted, thin and elonogated________.
a. sustenacular tubules
b. tunica vaginalis
c.seminiferous tubules
d. scrotal septum

10. Which is true about the blood flow of the tested?
a. the left gonadal vein drains directly into the inferior vena cava
b. the right gonadal vein drains directly into the left renal vein
c. the right gonadal vein drains directly into the inferior vena cava
d. none of the above

11. The ejaculatory duct is between ______________.
a. 1-2 centimeters long
b. the scrotum
c. 4-6 centimeters long
d. the gonadal arteries