Reproduction and development Part 4

Question 1

Spermatogenesis differs from oogenesis in three ways. Name those differences.

Answer 1

1. All four products of meiosis develop into sperm, while only one of the four becomes an egg.
2. Spermatogenesis occurs throughout adolescence and adulthood
3. Sperm are produced continuously without the prolonged interruptions in oogenesis

Question 2

Which hormones coordinate mammalian reproduction?

Answer 2

hormones from the hypothalamus, anterior pituitary, and gonads

Question 3

Gonadotropin-releasing hormone (GnRH) is secreted by ____ and directs the release of _____ and _____ from the anterior pituitary

Answer 3

hypothalamus, FSH (follicle-stimulating hormone) LH (Luteinizing hormone)

Question 4

FSH and LH are tropic hormones which means that they

Answer 4

trigger endocrine tissues to release other hormones

Question 5

FSH and LH act on the ___ and regulate the production of ___

Answer 5

gonads, sex hormones

Question 6

What are the major androgen and estrogens

Answer 6

androgen- testoterone
Estrogens- estradiol and progesterone

Question 7

Both males and females produce androgens and estrogens but differ in their

Answer 7

blood concentrations of particular hormones. For example. males have testosterone levels about 10 times higher than females)

Question 8

Sex hormones regulate gamete production only directly
True or False

Answer 8

False- It regulates it both directly and indirectly

Question 9

sex hormones have many additional functions. Name some

Answer 9

1. sexual behavior
2. development of primary and secondary characteristics

Question 10

Why do FSH and LH act on different cells in the testes?

Answer 10

to direct spermatogenesis

Question 11

Where are Sertoli cells found and what do they do?

Answer 11

Found- in the seminiferous tubules
what they do- respond to FSH by nourishing developing sperm

Question 12

Where are Leydig cells found and what do they do?

Answer 12

Found- in the connective tissue between tubules
What they do- respond to LH by secreting testosterone and other androgens which promote spermatogenesis

Question 13

What are the 2 negative feedback mechanisms that control sex hormone production in males

Answer 13

1. Testosterone regulates the production of GnRH,FSH, and LH through inhibitory effects on the hypothalamus and anterior pituitary
2. Sertoli cells secrete the hormone inhibin, which reduces FSH secretion from the anterior pituitary

Question 14

the hormone inhibin

Answer 14

helps Sertoli cells reduce FSH secretion from the anterior pituitary

Question 15

What are the two closely linked reproductive cycles in human females?

Answer 15

Ovarian and menstrual cycle

Question 16

Ovarian cycle

Answer 16

Cyclic events in the ovaries which releases an oocyte once per cycle

Question 17

Menstrual cycle AKA (Uterine cycle) is defined as

Answer 17

changes in the uterus

Question 18

What happens during each menstrual cycle

Answer 18

The endometrium thickens with blood vessels in preparation for embyo implantation and development

Question 19

What happens when an oocyte is not fertilized and pregnancy does not occur?

Answer 19

The uterine lining is sloughed off in a process called menstruation

Question 20

How long do menstrual and ovarian cycles average?

Answer 20

They average around 28 days but can range from about 20-40 days