Chapter 46.4

Question 1

Menstruation

Answer 1

If an embryo does not implant in the endometrium, the endometrium is shed in a process called menstruation

Question 2

The Ovarian Cycle

Answer 2

• The sequential release of GnRH then FSH and LH stimulates follicle growth
• Follicle growth and an increase in the hormone estradiol characterize the follicular phase of the ovarian cycle
• The follicular phase ends at ovulation, and the secondary oocyte is released
• Following ovulation, the follicular tissue left behind transforms into the corpus luteum; this is the luteal phase
• The corpus luteum disintegrates, and ovarian steroid hormones (Estradiol & progesterone) decrease

Question 3

The Uterine (Menstrual) Cycle

Answer 3

• Hormones coordinate the uterine cycle with the ovarian cycle
  
  • Thickening of the endometrium during the proliferative phase coordinates with the follicular phase
  • Secretion of nutrients during the secretory phase coordinates with the luteal phase
  • Shedding of the endometrium during the menstrual flow phase coordinates with the growth of new ovarian follicles

Question 4

Follicular Phase

Answer 4

Follicle growth and an increase in the hormone estradiol characterize the follicular phase of the ovarian cycle

Question 5

Luteal Phase

Answer 5

Following ovulation, the follicular tissue left behind transforms into the corpus luteum

Question 6

Ectopic

Answer 6

Cells of the uterine lining can sometimes migrate to an abnormal, or ectopic, location

Question 7

Endometriosis

Answer 7

Swelling of these cells in response to hormone stimulation results in a disorder called endometriosis

Question 8

Menopause

Answer 8

• After about 500 cycles, human females undergo menopause, the cessation of ovulation and menstruation

Question 9

Menstrual Versus Estrous Cycles

Estrous Cycles

Answer 9

• The endometrium is reabsorbed by the uterus
• Sexual receptivity is limited to a “heat” period
• The length and frequency of estrus cycles vary from species to species

Question 10

Inhibin

Answer 10

Sertoli cells secrete the hormone inhibin, which reduces FSH secretion from the anterior pituitary

Question 11

Human Sexual Response

Answer 11

• Two reactions predominate in both sexes
  
  • Vasocongestion, the filling of tissue with blood
  • Myotonia, increased muscle tension

Question 12

Orgasm

Answer 12

• Orgasm is characterized by rhythmic contractions of reproductive structures
  
  • In males, semen is first released into the urethra and then ejaculated from the urethra
  • In females, the uterus and outer vagina contract