1. The Reproductive System Lesson 3: The Male Reproductive System33
The Reproductive System
Lesson 3:
The Male Reproductive System

2. Lesson Objectives
Upon completion of this lesson, students should be able to …
Define and spell the terms to learn for this chapter.
Explain the purpose and function of the male reproductive system.
Identify the male external organs of reproduction and explain the function of each.

3. Lesson Objectives
Identify and state the function of the testes, epididymis, ductus deferens, seminal vesicles, prostate gland, bulbourethral glands, and the urethra.

4. The Male Reproductive System
The system consists of:
Testes
Various ducts
Urethra
Accessory organs
Accessory glands include the:
Bulbourethral
Prostate
Seminal vesicles
Supporting structures and accessory sex organs, the scrotum, and the penis

5. The Male Reproductive Organs5

6. External and Internal Organs
Scrotum
Penis
Internal
Testes
Epididymis
Ductus deferens (vas deferens)
Two seminal vesicles
Prostate gland
Bulbourethral glands
Urethra

7. External and Internal Organs7

8. Scrotum
Pouch-like structure behind the penis

9. Scrotum Pouch-like structure behind the penis
Suspended from the perineal region
Divided into two sacs by a septum
Each sac contains one of the two testes along with the epididymis, a connecting tube
Tissues of the scrotum have fibers of smooth muscle that contract in the absence of sufficient heat, giving the scrotum a wrinkled appearance

10. Scrotum
This contractile action brings the testes closer to the perineum, helping them to absorb sufficient body heat to maintain the viability of the sperm

11. Penis Composed of erectile tissue covered with skin
Size and shape of the penis vary; the average erect penis is about 15 to 20 cm in length
Three longitudinal columns of erectile tissue in the penis are capable of significant enlargement when engorged with blood, such as during sexual stimulation

12. Penis
Covered with a loose fold of skin called the foreskin or prepuce.
Foreskin contains glands that secrete a lubricating fluid called smegma

13. Erectile State in the Penis
Occurs when sexual stimulation causes large quantities of blood from dilated arteries supplying the penis to fill the cavernous spaces in the erectile tissue
When the arteries constrict, the pressure on the veins in the area is reduced, allowing more blood to leave the penis than can enter it, and the penis returns to its normal size

14. Erectile State in the Penis
The functions of the penis
To serve as the male organ for intercourse or copulation
The site of the orifice through which urine and semen are eliminated from the body

15. The Testes: Location and Structure
Two testes
Contained in scrotum
Scrotum: thin-walled muscular pouch 15

16. Critical Thinking Question
Can a man be potent if he has only one functioning testicle? 16

17. The Testes: Location and Structure17

18. Function of Testes Testes Produce male hormone – Testosterone
Responsible for development of the male secondary sex characteristics
Necessary for the reproductive act 18

19. Epididymis Coiled tube lying on the posterior aspect of the testes.
Between 13 and 20 feet in length
Coiled into a space less than 5 cm in length, and ends at the ductus deferens
Function is to serve as the:
Storage site for the maturation of sperm
First part of the duct system through which the sperm pass as they travel to the urethra 19

20. Ductus Deferens (vas deferens)
Slim, muscular tube about 45 cm in length that is continuous with the epididymis
Excretory duct of the testes
Extends from a point adjacent to the testes and enters the abdomen at the inguinal canal
A duct from the seminal vesicle joins the ductus deferens at the inguinal canal 20

21. Ductus Deferens (vas deferens)
Between the testes and the internal inguinal ring (part of the abdomen), the ductus deferens is contained within a structure known as the spermatic cord – The spermatic cord also contains arteries, veins, lymphatic vessels, and nerves 21

22. Two Seminal Vesicles Connected by a narrow duct to the ductus deferens
Forms the ejaculatory duct, a short tube that penetrates the base of the prostate gland and opens into the prostate portion of the urethra
Produce an alkaline fluid that becomes part of the seminal fluid or semen 22

23. Prostate Gland Lies behind the urinary bladder
Wraps around the first 2.5 cm of the urethra
About 4 cm wide
Composed of glandular, connective, and muscular tissue
Secretes an alkaline fluid that aids in maintaining the viability of the spermatozoa 23

24. Bulbourethral Glands Also known as Cowper’s glands
Two small, pea-sized glands
Located inferior to the prostate and on either side of the urethra
A 2.5-cm duct connects them with the wall of the urethra
Secrete a mucous secretion into the seminal fluid before ejaculation 24

25. Male Urethra Approximately 20 cm long Divided into three sections:
Prostatic
Membranous
Penile
Extends from the bladder to the urethral orifice at the end of the penis
Functions in the male are the expulsion of urine and semen from the body 25

26. Questions? 26