Week Thirteen

Question 1

How many chromosomes do gametes?

Answer 1

23, when combined → 46

Question 2

Describe spermatogenesis

Answer 2

• the process of sperm development
• begins at puberty and continues throughout life

Question 3

How many sperm do healthy young adult males make in a day?

Answer 3

400 million

Question 4

What are testosterone’s anabolic effects on the body?

Answer 4

increased bone density, skeletal muscle mass

Question 5

What are the behavioural effects of testosterone?

Answer 5

libido

Question 6

Other than testosterone, what else do the testes release? What does this hormone do?

Answer 6

inhibin which acts as a negative feedback regulator by inhibiting GnRH release

Question 7

When do testosterone levels and spermtogenesie remain fairly stable until?

Answer 7

70 years old

Question 8

What type of hormone is testosterone?

Answer 8

a steroid

Question 9

What hormone do the testes make testosterone in response to?

Answer 9

Luteinizing hormone

Question 10

What are the primary and secondary characteristics stimulated by testosterone?

Answer 10

• growth, maturation, & maintenance of male reproductive organs (testes, scrotum, penis)
• development of pubic, axillary, facial, chest hair, enlarged larynx and thicker vocal cords, increases secretions of sebaceous glands

Question 11

What are the 2 main functions of the ovaries?

Answer 11

produce locates and secrete hormones (estrogens and progesterone are the main ones)

Question 12

What is oogenesis? When does it begin?

Answer 12

• the process of oocyte development
• begins before female is born and then paused until puberty

Question 13

What are the three types of estrogen?

Answer 13

• estradiol, estrone, and estriol

Question 14

Describe the concept map of what occurs in a woman from puberty to menopause

Answer 14

once a month many immature oocyte within individual follicles are stimulated to continue development → only 1 oocyte will continues meiosis and be released during ovulation → if fertilized by sperm: oocyte completed maturation into an ovum, chromosomes combine and cell division occurs → if not fertilized by sperm: oocyte shed during menstruation

Question 15

What is the ovarian cycle?

Answer 15

maturation of the oocyte within a follicle

Question 16

How long is the ovarian cycle on average

Answer 16

28 days

Question 17

What are the three phases of the ovarian cycle?

Answer 17

follicular, ovulation, and luteal phase

Question 18

Describe the follicular phases of the ovarian cycle

Answer 18

day 1-13, length can be variable from person to person
- follicle grows and develops with oocyte inside

Question 19

Describe the ovulation phases of the ovarian cycle

Answer 19

day 14
- follicle ruptures to release the maturing oocyte → swept into the fallopian tube for its journey to the uterus

Question 20

Describe the luteal phase of the ovarian cycle

Answer 20

day 15-28
- left over ruptured follicle becomes the ‘corpus luteum’
- the corpus luteum secretes progesterone
if pregnancy occurs → corpus luteum will persist for ~ 3 months to produce progesterone
if NO pregnancy → corpus luteum will degenerate in 10 days

Question 21

What two hormones are released in response to Gonadotropin releasing hormone? What do they each do?

Answer 21

Luteinizing hormone: stimulates follicle cells to secrete androgens
Follicle stimulating hormone: stimulates conversion of androgens to estrogens and secretion of inhibin from follicle cells

Question 22

What is the result of the release of LH and FSH

Answer 22

• estrogens stimulate the dominant follicle to mature
• estrogen relays positive feedback to anterior pituitary, produces a surge in LH and FSH release → triggers ovulation
• after, inhibin and estrogens relay negative feedback to the hypothalamus and anterior pituitary

Question 23

What happens to hormonal control of the ovarian cycle if fertilization occurs?

Answer 23

extended progesterone release from the corpus luteum will continue to inhibit GnHR, LH, FSH release

Question 24

What happens to hormonal controls of the ovarian cycle if np fertilization occurs?

Answer 24

corpus luteum will degenerate → estrogen and progesterone levels drop → cycle begins again

Question 25

Which hormone is the primary hormone produced by the corpus luteum?

Answer 25

progesterone

Question 26

What is the endometrium? How is it affected by the uterine cycle?

Answer 26

the innermost lining of the uterus
- undergoes cyclic changes in response to ovarian hormones
- if no pregnancy → detaches from the uterine wall and is shed as a discharge of 35-50 mL of blood with other fluid once per month (menstruation)

Question 27

What are the three phases of the uterine cycle?

Answer 27

menstrual phase, proliferative phase, and secretory phase

Question 28

Describe the menstrual phase of the uterine cycle?

Answer 28

day 1-5 - old layer is shed
- FSH and LH begin to rise at day 1

Question 29

Describe the proliferative phase of the uterine cycle

Answer 29

day 6-14 - new layer develops and thickens
- rising estrogen levels → ++FSH & LH peak at day 14

Question 30

Describe the secretory phase of the uterine cycle

Answer 30

day 15-28 - lining is maintained to accommodate potential implantation of fertilized egg
- progesterone rises, estrogen decreases, LH and FSH release inhibited

Question 31

What phases does the secretory phase of the uterine cycle corresponds to the ___________ phase of the ovarian cycle

Answer 31

luteal phase

Question 32

What are the other effects of estrogen?

Answer 32

stimulate development of secondary sex characteristics
- external genitalia, breasts, fat accumulation around hips and thighs, pubic and axillary hair, increased secretions of sebaceous glands
bone and skeletal muscle mass development (less potent than testosterone)
estrogens also exert a protective effect on the body

Question 33

How do estrogens exert a protective effect on the body

Answer 33

• inhibit bone resorption (by inhibiting osteoclasts)
• increased HDL level and decreased LDL level
• general protective effect on the cardiovascular system