4.1 Sexual Reproduction In Humans

Question 1

What are the reproductive and urinary systems being closely bound together referred to as?

Answer 1

The Urinogenital System

Question 2

Where are gametes produced?

Answer 2

In paired glands - called Gonads

Question 3

What are the male gametes?

Answer 3

Spermatozoa (sing. spermatozoon)

Question 4

What are the female gametes called?

Answer 4

Ova (sing. ovum)

Question 5

Where are the testes (glands) situated?

Answer 5

In the scrotal sac - hangs outside main body cavity

Question 6

What is the advantage of the scrotal sac hanging outside the main body cavity?

Answer 6

Allows the testes to be kept 2 - 3C lower than normal body temperature - optimum temp for sperm production

Question 7

Besides sperm, what else do the testes produce?

Answer 7

Testosterone - makes the testes endocrine (secretion) glands.

Question 8

Where is the sperm stored?

Answer 8

In coiled tubes - called the epididymis

Question 9

Where is the sperm passed out after being stored?

Answer 9

Along the sperm duct - called the vas deferens

Question 10

What is the process called where the sperm are carried in a fluid and passed out?

Answer 10

Ejaculation

Question 11

What do the seminal vesicles & prostate glands do (exocrine glands)?

Answer 11

They secrete the fluid that the spermatozoa are transported in

Question 12

What does the contraction of muscles around the prostate gland & seminal vesicle do?

Answer 12

Forces out fluid that mixes with the sperm

Question 13

What does fluid from the seminal vesicle contain?

Answer 13

Fructose

Question 14

What does the fluid from the prostate gland do?

Answer 14

It is alkaline, so neutralises the acid from the urine in the urethra and the acidity of the vaginal tract

Question 15

What is the mixture of sperm and the fluid from the seminal vesicles and prostate gland called?

Answer 15

Semen

Question 16

What is the pH of semen?

Answer 16

7.5

Question 17

Where does the urethra run?

Answer 17

Through the penis

Question 18

What does the urethra carry?

Answer 18

Semen during ejaculation, and urine during urination

Question 19

What does the penis contain?

Answer 19

Spongy erectile tissue that can fill with blood when sexually stimulated

Question 20

What happens to the penis when sexually stimulated?

Answer 20

It enlarges, lengthens, and becomes rigid - known as erection

Question 21

Where are the ovaries held?

Answer 21

Near the base of the abdominal cavity

Question 22

Where do oocytes mature?

Answer 22

In follicles - these develop from cells in the germinal epithelium, around the periphery of the ovary.

Question 23

Where do mature follicles migrate?

Answer 23

The surface of the ovary - this is where a secondary oocyte is released at ovulation

Question 24

What do the oviducts do?

Answer 24

They are the site of fertilisation- they extend from the uterus and open as funnels close to the ovary.

Question 25

What do cilia do?

Answer 25

They sweep the secondary oocyte into the oviduct

Question 26

What do ciliated epithelial cells do?

Answer 26

They line the oviduct, and convey the secondary oocyte to the uterus

Question 27

What do the ovaries (endocrine glands) secrete?

Answer 27

Oestrogen and progesterone

Question 28

What are the three layers of the uterus?

Answer 28

1. Perimetrium - a thin layer around the outside 2. Myometrium - a muscle layer 3. Endometrium - the innermost layer

Question 29

What is the endometrium?

Answer 29

A mucous membrane, well supplied with blood It builds up and sheds in a monthly cycle, unless an oocyte is fertilised

Question 30

What happens when an oocyte is fertilised?

Answer 30

It will implant itself in the endometrium, establishing a pregnancy

Question 31

Where is the vagina connected?

Answer 31

To the uterus at the cervix, and opening to the exterior at the vulva.

Question 32

What is the name for the production of gametes in the sex organs?

Answer 32

Gametogenesis

Question 33

What is the name for the formation of spermatozoa in the testes?

Answer 33

Spermatogenesis

Question 34

What is the name for the production of secondary oocytes in the ovaries?

Answer 34

Oogenesis

Question 35

What are inside of the testes?

Answer 35

Seminiferous Tubules

Question 36

What is each seminiferous tubule surrounded by?

Answer 36

A layer of germinal epithelium, which has spermatogonia sitting on it.

Question 37

Are germinal epithelium cells haploid or diploid?

Answer 37

Diploid

Question 38

How do the cells of the germinal epithelium divide, and what do they make?

Answer 38

They divide by mitosis They make diploid spermatogonia & more germinal epithelium cells

Question 39

What some of the spermatogonia do?

Answer 39

Stay near the edge of the tubule, forming more spermatogonia

Question 40

What do other spermatogonia do?

Answer 40

Move towards the middle of the tubule & grow larger - forming primary spermatocytes

Question 41

What does each primary spermatocyte divide by?

Answer 41

Meiosis

Question 42

What does the first meiotic division form?

Answer 42

Two secondary spermatocytes from each primary spermatocyte

Question 43

Are the secondary spermatocytes diploid or haploid?

Answer 43

Haploid

Question 44

What does the second meiotic division of the secondary spermatocyte produce?

Answer 44

Two haploid spermatids

Question 45

What do the spermatids mature into?

Answer 45

Spermatozoon

Question 46

What are the developing sperm cells protected by?

Answer 46

Sertoli Cells - non dividing cells, and are very large

Question 47

What is needed for spermatogenesis to take place?

Answer 47

Male sex hormones - testosterone - secreted into the bloodstream by interstitial cells (cells of Leydig) stimulating process of spermatogenesis