EXAM 4 start: Panopto 31 Male Reproductive

Question 1

When do the reproductive tissues, or gonads, become active? When do they become dormant? Re-active again?

Answer 1

They first become active in utero during the embryonic and fetal development. It then becomes dormant at birth until 10 to 14 years later, when the activity starts again during puberty

Question 2

What happens during conception? How do the cells unite?

Answer 2

2 haploid cells, one female and one male, each containing 23 chromosomes, unite to form a single diploid cell called a zygote, and they unite through a process called syngamy.

Question 3

When a new diploid cell is formed after conception, how many chromosomes does it have? How many are sex chromosomes?

Answer 3

46, 2 of which are sex chromosomes

Question 4

what do XX and XY mean?

Answer 4

XX- female XY-male

Question 5

When does the undifferentiated gonad develop?

Answer 5

5 weeks post conception

Question 6

What does an undifferentiated gonad mean?

Answer 6

it is not morphologically distinct, but it is determined genetically

Question 7

When does it become morphologically distinct?

Answer 7

7 weeks we can tell if its male or female

Question 8

In a male, what does the undifferentiated gonad develop into?

Answer 8

testis

Question 9

In a female, what does the undifferentiated gonad develop into?

Answer 9

ovary

Question 10

What is the development of the gonads controlled by?

Answer 10

the chromosomes. Once a testis/ovary is developed, the chromosomes are done

Question 11

What is in control after the chromosomes have done their job in development?

Answer 11

Hormones

Question 12

What 2 cells are present in the testis that are responsible for male development? Where are they found?

Answer 12

1. sertoli cells found in semniferous tubules
2. leydig cells or interstital cells (in the connective tissue outside the seminiferous tubules)

Question 13

What’s another name for Leydig cells?

Answer 13

interstitial cells

Question 14

What are the 2 ducts that each embryo has that play a role in the development of reproductive anatomy?

Answer 14

1. Mullerian duct
2. mesonephric duct (wolffian duct)

Question 15

What’s another term for mesonephric duct?

Answer 15

Wolffian duct

Question 16

What do sertoli cells produce? What does it do?

Answer 16

produce anti-mullerian hormone (causes the mullerian duct to dissapear over time) It disappears because the mullerian duct develops into a female tract, and since it is male reproductive, it isn’t needed.

Question 17

What do Leydig cells produce?

Answer 17

produce steroid hormones
1. testosterone (T): stimulates the mesonephric ducts that develop into the male reproductive tract
2. T & dihydrotestosterone (DHT): influence the development of the external genitalia, and that includes the penis and scrotum.
3. T & estradiol: go to the brain and program the part of the brain that controls the gonads when the fetus becomes an adult. (The portion of the brain that does this is the hypothalamus.)

Question 18

Can DHT work alone?

Answer 18

no it must work in conjunction with testosterone

Question 19

When are the male parts formed, and when has the brain been programmed?

Answer 19

4 and a half months post conception

Question 20

what cells are gone when birth occurs?

Answer 20

leydig cells, they disappeared

Question 21

When do Leydig cells reappear?

Answer 21

10 to 14 years after birth during puberty

Question 22

what happens if the sertoli cells and leydig cells aren’t functioning properly?

Answer 22

1. the sertoli cells wont produce the anti-mullerian hormone, meaning the female reproductive system will begin to develop in a male
2. the Leydig cells either inactive or missing can not then further develop the male

Question 23

what are the 2 categories of the male reproductive system? What do they do?

Answer 23

1. Primary sex organs: 2 testes
   What do the testes do? Create germ cells, gametes, and sex cells (spermatozoa). these terms can be used for both genders but spermatozoa is exclusively male
2. Accessory reproductive structures
   a) Epididymis: maturing and storing station for nonfucntional spermatozoa. They are kept there until they are mature.
   b) Seminal vesicles: Do NOT contain semen or germ cells. They produce a fluid high in fructose that is used by the spermatozoa for motility. Without fructose, they cannot move. Accounts for 70% of the fluid volume for semen.
   c) Prostate: produces fluid/proteins (PSA: prostate-specific antigen). Also secrete enzymes (serine protease: liquify the semen since the fluid from the seminal vesicles is thick; it helps thin it out)
   d) Bulbourethral glands: produces a fluid that is a lubricant for the urethra. Allows ejaculation to be more efficient
   e) penis etc: scrotum and vas deferens