IN PROGRESS - Reproductive System I (Male)

Question 1

Is the reproductive system necessary to individual life?

Answer 1

No.
However, it is necessary for the continuation of a species.

Question 2

What are the male reproductive structures?

Answer 2

Gonads, ducts, accessory glands, external genitalia.

Question 3

What are gonads?

Answer 3

Organs that produce gametes and hormones

Question 4

What do ducts do?

Answer 4

Receive and transport gametes.

Question 5

What do reproductive accessory organs do?

Answer 5

Secrete fluid into ducts.

Question 6

What is the function and location of the male gonads?

Answer 6

Testis: produce sperm.
Suspended in the scrotum. Part of the external genitalia.

Question 7

What is the path traveled by sperm?

Answer 7

Generated in the testis, travel into the epididymis, then into the ductus/vas deferens, it then combined with the secretions of accessory organs and enters the ejaculatory duct, which joins with the urethra.

Question 8

What are the three accessory glands? What do they do?

Answer 8

Seminal gland: releases secretions (70% of ejaculated semen) into the ejaculatory duct. Located between the bladder and rectum.

Prostate gland: releases 25% of the ejaculate. Inferior to the bladder and seminal gland.

Bulbourethral gland: secretions help to lubricate the penis. Inferior to the prostate gland.

Question 9

What are spermatic cords?

Answer 9

Bundles of nerves, ducts (vas deferens), and blood vessels suspending the testis in the scrotal sac from the abdomen.
Cords begin at the inguinal canal.

Question 10

What causes an inguinal hernia?

Answer 10

Visceral structures (ex. small intestine) protrudes into the inguinal canal (passageway through abdominal muscle).
Likely due to weakness or increased stress of abdominal muscles.
Treated with surgery.

Question 11

Why are the testis housed in the scrotal sac?

Answer 11

Temperature regulation.

Normal sperm development requires a temperature around 1*C lower than normal body temperature.

Question 12

How is temperature regulated in the scrotum?

Answer 12

Regulated with the cremaster and dartos muscles.

Body temp increase: muscles relax, moving the testis farther away to cool down.

Body temp drop: muscles contract to bring testis closer to the body for warmth.

Question 13

What are seminiferous tubules?

Answer 13

Location of sperm production. Slender, tightly coiled tubules in the lobules of the testis. Separated by CT.

Question 14

Describe the stages of spermatogenesis in a seminiferous tubule.

Answer 14

Inside spermatogonium cell:
1. Primary spermatocyte prepares for meiosis I.
2. Two secondary spermatocytes (spermatids) are formed when a primary spermatocyte undergoes meiosis I.
3. Spermatids will begin spermiogenesis, creating sperm which will leave through the lumen.

Question 15

What are nurse/Sertoli cells?

Answer 15

Forms pocket where sperm develops.

Large cells extending from the basement membrane to the lumen.

Question 16

Where are the interstitial endocrine / Leydig cells?

Answer 16

Produce hormones like testosterone.

Found below the basement membrane in the CT.

Question 17

Describe the blood-testis barrier.

Answer 17

Formed by tight junctions so sperm does not come into contact with immune cells.

Question 18

What are the key differences between mitosis and meiosis?

Answer 18

Mitosis: Parent cell results in two identical daughter cells.
Fewer steps of division, more genetic material (46 C).

Meiosis: Parent cell results in four unique daughter cells.
More steps of division, has less genetic material at the end (23 C).

Question 19

What are the stages of mitosis?

Answer 19

1. Prophase
2. Metaphase
3. Anaphase
4. Telophase and cytokinesis

Question 20

What are the stages of meiosis?

Answer 20

1. Prophase I
2. Metaphase I
3. Anaphase I
4. Telophase I
5. Metaphase II
6. Anaphase II
7. Telophase II and cytokinesis

Question 21

What happens during prophase? Prophase I?

Answer 21

DNA is replicated, forming sister chromatids (identical chromosomes held together at the centromere).

I: Same thing, but homologous chromosomes stay in close proximity forming tetrad structures. This allows for cross over/homologous recombination.

Question 22

What happens during metaphase (I)?

Answer 22

Genetic material is arranged along the midline

Question 23

What happens during anaphase? Anaphase I?

Answer 23

Sister chromatids are pulled apart to opposite sides of the cell.

I: Chromatids remain together, but the tetrads are pulled apart. Double the genetic material on each side.

Question 24

What happens during telophase?

Answer 24

A new membrane is formed around each half of the cell, cleaving it into two.