3. Male Reproduction

Question 1

List the parts of the male reproductive tract.

Answer 1

• Spermatic cord
• Scrotum
• Testis
• Excurrent duct system
• Accessory sex glands
• penis

Question 2

What is the purpose of the spermatic cord?

Answer 2

• Provides unique thermoregulated environment for the testis
• Provides pathway to and from the body for vasculature, lymphatics, and nervous functions
• Suspends the testis in the scrotum
• Also houses the ductus deferens, cremaster muscle, and pampiniform plexus

Question 3

What muscle of the testis contracts and relaxes to facilitate blood flow and cooling efficiency of the testis?

Answer 3

cremaster muscle

Question 4

What muscle of the testis is capable of sustained contractions to help in temperature regulation (Testis held close to body during cold temperatures)?

Answer 4

tunica dartos

Question 5

Part of the male reproductive tract involved in temperature regulation, testicular hormone concentration, and pulse elimination?

Answer 5

pampiniform plexus

Question 6

How many degrees Celsius cooler do the testis need to be compared to the body?

Answer 6

4 to 6° C cooler

Question 7

What are the 4 major layers in the scrotum?

Answer 7

• Skin
• Tunica dartos
• Scrotal fascia
• Parietal tunica vaginalis

Question 8

cremaster muscle is made of striated or smooth muscle fibers?

Answer 8

striated, cannot sustain contractions

Question 9

What are the 3 main functions of the scrotum?

Answer 9

thermosensor
radiator
protective sac

Question 10

tunica dartos is made of striated or smooth muscle fibers?

Answer 10

smooth, can maintain sustained contractions in intact males

Question 11

What happens to the tunica dartos’s ability to contract in castrated males?

Answer 11

Ability of tunica dartos to contract is lost because testosterone is absent

Question 12

What is the male gonad?

Answer 12

testes

Question 13

Production of _____ and _____ occurs in the testis?

Answer 13

spermatozoa & testosterone

Question 14

What are the two layers of the testicular capsule?

Answer 14

visceral tunica vaginalis and tunica albuginea

Question 15

What is the significance of the smooth muscle that undergoes rhythmic contractions in the testes?

Answer 15

“pumping action” contractions move spermatozoa into rete tubules

Question 16

What is the mediastinum and what does it contain?

Answer 16

• Mediastinum is the central connective tissue core of the testis
• houses the rete tubules (tiny channels through which spermatozoa are transported out of the testis)

Question 17

What makes up the tubular compartment?

Answer 17

seminiferous tubules with sertoli cells

Question 18

The interstitial compartment contains what type of cells?

Answer 18

leydig cells

Question 19

What cells produce testosterone in response to LH?

Answer 19

leydig cells

Question 20

Where is the site of spermatogenesis?

Answer 20

seminiferous epithelium

Question 21

What are the only somatic cells in the seminiferous epithelium?

Answer 21

sertoli cells

Question 22

What do the Sertoli cells surround?

Answer 22

the developing population of germ cells

Question 23

Which two compartments do the Sertoli cell junctional complexes separate?

Answer 23

Separate the basal from the adluminal compartments

Question 24

Which compartment contains spermatogonia and early primary spermatocytes?

Answer 24

basal compartment

Question 25

Which compartment contains primary and secondary spermatocytes and spermatids?

Answer 25

adluminal compartment

Question 26

Why are germ cells targeted by the immune system?

Answer 26

Germ cells are haploid, thus are foreign

Question 27

What is the purpose of the tail of the epididymis?

Answer 27

Storage and final maturation of the spermatozoa, acquisition of motility and potential fertility

Question 28

What are the three distinct regions of the epididymis?

Answer 28

- Head (coput) - Body (corpus) - Tail (cauda)

Question 29

What is the purpose of the accessory sex glands?

Answer 29

Produce seminal plasma, the non-cellular fluid portion of semen

Question 30

What is the purpose of seminal plasma?

Answer 30

acts as a vehicle for spermatozoal delivery to the female

Question 31

Enlargements of the ductus deferens that open into pelvic urethra

Answer 31

ampullae

Question 32

Which species has the largest bulbourethral glands?

Answer 32

boar (porcine)

Question 33

list the 3 accessory sex glands

Answer 33

- vesicular glands - prostate gland - bulbourethral glands

Question 34

what is the copulatory organ in the male?

Answer 34

penis

Question 35

What are the three parts of the penis?

Answer 35

- Base (root) - Shaft (main portion) - Glans penis (specialized distal end)

Question 36

What is the primary factor initiating ejaculation?

Answer 36

Stimulation of the glans penis

Question 37

What type of penis do bulls, boars, and rams have?

Answer 37

Fibroelastic penis with limited erectile tissue encased in non-expandable, dense connective tissue

Question 38

What structure is unique to animals with a fibroelastic penis?

Answer 38

Sigmoid flexure: S-shaped configuration along shaft of penis

Question 39

what does the sigmoid flexure allow to happen?

Answer 39

Allows for retraction inside the body

Question 40

One of the functions of the testes is the production of the hormone ________, which is synthesized by the ________ located within the ________ of the testicular parenchyma.

Answer 40

testosterone; Leydig cells; interstitial compartment

Question 41

There are two compartments within the ______, the site where spermatogenesis occurs. The ______ serves as an anchor for _____ cells, which surround the population of germ cells.

Answer 41

seminiferous tubules; basement membrane; sertoli

Question 42

The penis consists of three parts. The base, the shaft, and the glans penis. The shaft includes an area of spongy erectile tissue known as ______

Answer 42

corpus cavernosum

Question 43

What prevents the immunological destruction of developing germ cells?

Answer 43

blood-testis barrier

Question 44

The testicular parenchyma houses the major cellular mass of the testes. It consists of what two compartments?

Answer 44

Tubular compartment and Interstitial compartment

Question 45

Bulls, boars and rams have what kind of penis?

Answer 45

fibroelastic

Question 46

Heavily populated with sweat glands that contribute to testicular temperature regulation.

Answer 46

scrotal skin

Question 47

The testes are covered by a dynamic sub-organ called the _______. This sub-organ includes the ______ which contains ______ that allows small contractions to provide pumping action for the movement of spermatozoa.

Answer 47

testicular capsule; tunica albuginea; smooth muscle fibers

Question 48

Which type of erectile tissue surrounds the penile urethra?

Answer 48

Corpus spongiosum

Question 49

What are the four muscles associated with the penis?

Answer 49

- Urethralis - Bulbospongiosus - Ischiocavernosus - Retractor penis

Question 50

What cell type within the testes produces testosterone?

Answer 50

leydig cells

Question 51

name two structures involved in thermoregulation of the testes.

Answer 51

pampiniform plexus (countercurrent heat exchanger) and tunica dartos (contracts to hold testis close to the body during cold temperatures)