Topic 2 Human Reproductive Anatomy: Male Reproductive System

Question 1

• Each consists of seminiferous tubules for production of sperm, and interstitial cells (Leydig cells) that produce male sex hormones testosterone and androgens at the beginning of puberty. These hormones are secreted in the presence of LH.

Answer 1

1. Testis

Question 2

a. Sertoli Cells

b. Scrotum

Answer 2

Parts of Testis

Question 3

• Are stimulated by FSH and serve to surround and nurture sperm, as well as secrete peptide hormone inhibin, which acts on the anterior pituitary to inhibit FSH release

Answer 3

a. Sertoli Cells

Question 4

• Testis are located here; provides an external cavity, about 2o C lower than the body temperature, for sperm production

Answer 4

b. Scrotum

Question 5

• A coiled tube attached to each testis that serves as the site for final maturation and storage of sperm

Answer 5

2. Epididymis

Question 6

• Transfers sperm from one epididymis to the urethra

Answer 6

3. Vas Deferens

Question 7

• Two glands that, during ejaculation, secrete into vas deferens and provide mucus (liquid for sperm), fructose (energy for sperm), and prostaglandins (stimulate uterine contractions that help sperm move into uterus)

Answer 7

4. Seminal Vesicles

Question 8

• Secretes milky alkaline fluid into urethra and neutralizes acidity of urine that may still be in the urethra, as well as acidity of the vagina. This gland also neutralizes seminal fluid, which is too acidic from metabolic waste of sperm

Answer 8

5. Prostate Gland

Question 9

• Secrete small amount of thick mucus of unknown function into urethra

Answer 9

6. Bulbourethral (Cowper’s) glands

Question 10

• Transports semen (fluid containing sperm and secretions) into the vagina

Answer 10

7. Penis

Question 11

• Are compact packages of DNA specialized for effective male genome delivery. Contains the following three segments:

Answer 11

8. Sperm

Question 12

a. Sperm Head
b. Mid-piece
c. Tail

Answer 12

Parts of Sperm

Question 13

• Haploid (23 chromosomes); at tip is acrosome, a lysosome-like organelle containing enzymes (hyaluronidase), which are used to penetrate the egg. The acrosome originates from Golgi body vesicles that fuse together, and only the nuclear portion of the sperm enters the egg

Answer 13

a. Sperm Head

Question 14

• Flagellum (9+2 microtubule array) arising from one member of centriole pair, and contains lots of mitochondria

Answer 14

b. Mid-piece

Question 15

• Remainder of flagellum; sperm is propelled by whiplike motion of tail and mid-piece

Answer 15

c. Tail

Question 16

• Use the mnemonic SEVEn UP to memorize the path of sperm: Seminiferous tubules —> Epididymis —> Vas deferens —> Ejaculatory duct —> Urethra —> Penis (pause before the V for maturation!)

Answer 16

Note