Male Reproductive System

Question 1

What are the organs of the male reproductive system?

Answer 1

Testes
System of Ducts (epidydimitis, ductus deferens, ejaculatory ducts, bulbourethral glands)
Supporting structures (scrotum, penis)

Question 2

What are the testes?

Answer 2

Paired oval glands that produce sperm and secrete hormones.

Develop in the abdominal activity and descend into the scrotum in the seventh month of the fetal development.

Lobules
Covered by a dense white capsule that divides each teste into lobules
Each of the 200-300 lobules contains 1-3 tightly coiled seminiferous tubules
Tubules are lined with sperm forming cells called spermatogenic cells
After a sperm cell is formed it is released into the lumen of the seminiferous tubule.

Question 3

What are Sertoli cells?

Answer 3

Nourish sperm cells and release the hormone inhibin.

Question 4

What are the leydig cells?

Answer 4

Secrete testosterone

Question 5

What is the most important androgen?

Answer 5

Testosterone
Promotes libido and male characteristic development

Question 6

What is the scrotum?

Answer 6

Pouch that supports the testes.
Septum divides the strum into two sacs each containing a single teste.
Production and survival of sperm is optimal 2-3 degrees Celsius below body temp.
Maintained with scrotum outside pelvic cavity.
Cremasteric muscle raises and lowers the teste to adjust temperature.

Question 7

Where does sperm production occur?

Answer 7

In the testes and consists of meiosis 1, meiosis 2, and spermatogenesis.

Results in the formation of four haploid sperm cells from a primary spermatocyte.

Begins during puberty and continues throughout life.

From onset until release is 65-75 days.

Spermatogonia contain the diploid number of chromosomes 2N=46

Spermatogonia undergo mitosis
One stays in tubule as stem cell spermatagonia
Other turns into primary spermatocyte

Question 8

Which spermatocyte undergoes meiosis 1?

Answer 8

Primary, resulting in two haploid secondary spermatocyte

Question 9

Which spermatocyte undergoes meiosis 2?

Answer 9

Secondary, resulting in four haploid secondary spermatids

Question 10

What is the final stage of spermatogenisis?

Answer 10

One spermatocyte creating four sperm.

Question 11

At what rate is sperm produced?

Answer 11

300 million a day
Most don’t survive 48 hrs once ejaculated

Question 12

What are the major parts of sperm?

Answer 12

Head- DNA and Acrosome
Tail-mitochondria and flagellum

Question 13

What is the epidydimis?

Answer 13

Tightly coiled ductus epidydimis. Stores sperm and helps propel them during sexual arousal to the vas deferens.
This is where spermat mature and acquire motility and ability to fertilize an egg
Can remain in storage for several months

Question 14

What makes up the spermatic cord?

Answer 14

Ascending with the vas are blood vessels, nerves, lymphatic vessels and cremasteric muscle.

Question 15

What are the ejaculatory ducts?

Answer 15

Formed by the Union of the duct of the ductus deferens and the seminal vesicles. Carry sperm to the urethra.

Question 16

What is the urethra?

Answer 16

Terminal duct of the male reproductive system. Passes through prostate, deep perineal muscles and penis.

Question 17

What do the accessory sex glands do?

Answer 17

Secrete most of the liquid portion of semen.
Seminal vesicles
Prostate
Bulbourethral glands

Question 18

What are the seminal vesicles?

Answer 18

Pouch like structures sitting posterior to the base of the urinary bladder.

Secrete an alkaline viscous fluid.

Secrete most of the liquid portion of semen and contain fructose, prostaglandin and clotting proteins.

Helps neutralize acidic nature of urethra and female reproductive tract.

60% of semen volume

Question 19

What is the prostate?

Answer 19

Single doughnut shaped gland about the size of a golf ball.

Inferior to bladder, surrounds the upper portion of the urethra.

Secretes a milky, slightly acidic fluid 6.5 that contains citric acid, phosphatase, and protein digesting enzymes.

25% of semen volume

Question 20

What are the bulbourethral glands?

Answer 20

Inferior to the prostate on either side of the urethra.

Secrete an alkaline substance into the urethra which protects the passing sperm by neutralizing acids from urine in the urethra.

Mucus that lubricators the end of the penis and lining of the urethra decreasing sperm damage.

Question 21

What is semen?

Answer 21

Mixture of sperm and the secretions of the seminal vesicles, prostate,, and bulbourethral glands.

Volume of semen in a typical ejaculation is 2.5-5mL, with 50-150 million/mL.

Slightly alkaline ph of 7.2 to 7.7 due to higher ph and other volume of fluid from the seminal vesicles.
Prostatic secretion is what gives it a milky appearance.
Fluids from the seminal vesicles and bulbourethral glands give it a sticky consistency.

Question 22

What is the penis?

Answer 22

Contains the urethra, root, body, and gland penis and serves as the passageway for ejaculation of semen and excretion of urine.

Root-attached portion
Body- two corpus cavernosa, one corpus spongiosum(spongiousum contains urethra)

Distal end of spongiosum is glans penis.

Question 23

What is an erection?

Answer 23

Enlargement and stiffening of the penis.
Parasympathetic impulses
Dilation of penile arteries
Volume compresses veins and drainage is slowed

Question 24

What is ejaculation?

Answer 24

Powerful release of semen from the urethra to the exterior. A sympathetic reflex.

Question 25

At puberty what does the hypothalamus increase secretion of?

Answer 25

Gonadtropin releasing hormone

Question 26

What does gnrh stimulate?

Answer 26

Pituitary gland to increase secretion of luteinizing hormone and follicle stimulating hormone

Question 27

LH and FSH control what?

Answer 27

Interstitial and sustentacular cells.

Question 28

What does oh stimulate the interstitial cells to do?

Answer 28

Secrete testosterone.

Question 29

Test acts in a negative feedback banner to what?

Answer 29

Suppress secretion of lh and GnRH

Question 30

What do fsh and testosterone act together to stimulate?

Answer 30

Testosterone

Question 31

What cells are released one the rate of spermatogenesis required has been reached.

Answer 31

Inhibin

Question 32

What do test and dihydrotestosterone both bind to, to produce several effects?

Answer 32

Androgen receptors
Prenatal development
Development of male secondary characteristics
Development of sexual function
Stimulation of anabolism