27. Reproductive System

Mark the following statements about oogenesis as true or false. If a statement is false, correct it to make a true statement.

b. About once a month after puberty begins, some primary oocytes are stimulated to continue development. Usually one will complete the first meiotic division to produce two haploid cells that are the same size.

Mark the following statements about oogenesis as true or false. If a statement is false, correct it to make a true statement.

c. The fate of all polar bodies is the same; they all degenerate and are reabsorbed by the body.

Mark the following statements about oogenesis as true or false. If a statement is false, correct it to make a true statement.

d. Only if a secondary oocyte is fertilized will it complete the second meiotic division and expel the last polar body.

Match the follicle stage with the correct description.

________ primordial follicle

________ Primary follicle

________ Secondary follicle

________ Vesicular follicle

________ Corpus luteum

________ Corpus albicans

a. Several layers of granulosa cells with pockets of follicular fluid surround the primary oocyte.

b. Knot of whitish scar tissue

c. Yellow glandular-looking endocrine structure

d. A single layer of squamous follicular cells surrounds the primary oocyte.

e. One or two layers of cuboidal granulosa cells surround the primary oocyte.

f. Several layers of granulosa cells surround the secondary oocyte and project into the antrum.

Number the sequence of events in the hormonal regulation of female reproduction, placing a 1 by the first event, and so forth.

________ Increasing levels of estrogens and inhibin exert negative feedback controls on the hypothalamus and pituitary to inhibit the release of more FSH and LH, leaving only one follicle to survive.

________ LH and FSH surge stimulates the primary oocyte of one follicle to complete meiosis to metaphase II, which triggers ovulation.

________ FSH and LH stimulate follicles to grow and secrete estrogens and inhibin.

________ Progesterone from the corpus luteum inhibits the release of gonadotropins and will continue to do this if pregnancy is achieved.

________ The hypothalamus releases GnRH.

________ A single follicle produces enough estrogens to exert positive feedback on the hypothalamus and anterior pituitary to trigger an LH surge.

________ The GnRH level rises to begin the cycle over.

.________ LH transforms the ruptured follicle into the corpus luteum, which produces progesterone and some estrogens.

________ If pregnancy does not occur, the corpus luteum degenerates into the corpus albicans and the progesterone level drops.

________ GnRH stimulates the anterior pituitary to secrete FSH and LH.

Mark the following statements about the uterine cycle as true or false. If a statement is false, correct it to make a true statement.

a. During the proliferative phase, the endometrium prepares for the implantation of the conceptus by enlarging the endometrial glands and secreting glycogen into the uterine cavity.

Mark the following statements about the uterine cycle as true or false. If a statement is false, correct it to make a true statement.

b. During the secretory phase, the endometrium generates a new stratum functionalis.

Mark the following statements about the uterine cycle as true or false. If a statement is false, correct it to make a true statement.

c. During the menstrual phase, the uterus sheds the stratum basalis of the endometrium, which results in the discharge of blood and tissue from the vagina.

Which of the following hormones stimulates the generation of a new stratum functionalis in the endometrium?

a. Estrogens

b. Progesterone

c. Inhibin

d. LH

e. FSH

How might the female orgasm increase the chance for fertilization to occur?

Explain why oral contraceptives, which artificially raise levels of estrogens and progesterone, prevent pregnancy.

Mark the following statements about oogenesis as true or false. If a statement is false, correct it to make a true statement.

a. Oogenesis begins before a female is born and continues for the remainder of her life.

Fabiola, a 17-year-old college student, suffers from an eating disorder. Her percentage of body fat has dropped to 14%. Her menstrual cycles were irregular, and now they have stopped altogether. Why do you think this has happened? Could the lack of menstrual periods be beneficial in this situation? Explain.

Mark the following statements about fertilization as true or false. If a statement is false, correct it to make a true statement.

c. Secondary oocytes are covered with a layer of cells called the zona pellucida.