Physiology and Endocrinology of Uterine & Ovarian Cycles (Week 1)

Question 1

What is the duration of the menstrual cycle?

Answer 1

28-day cycle (25-35 days range)

The cycle duration can vary among individuals.

Question 2

What marks the end of the luteal phase?

Answer 2

Atrophy of corpus luteum results in decline of progesterone

This leads to the sloughing off of the uterine lining.

Question 3

What hormone is released from the arcuate and preoptic nuclei in the hypothalamus?

Answer 3

Gonadotropin releasing hormone (GnRH)

GnRH stimulates the synthesis and release of LH and FSH from the anterior pituitary.

Question 4

What effect does a rapid pulse of GnRH have on LH?

Answer 4

Promotes Luteinizing hormone (LH) secretion

A slower pulse promotes follicle stimulating hormone (FSH) secretion.

Question 5

What do Theca Cells produce when stimulated by LH?

Answer 5

Progesterone and androgens

They are involved in steroidogenesis.

Question 6

What do Granulosa Cells convert under FSH guidance?

Answer 6

Androgens into estrogens

They also produce activins, inhibins, and follistatin.

Question 7

How do estrogens and progesterone impact the hypothalamus and pituitary?

Answer 7

Induce negative feedback to inhibit GnRH

This occurs most of the menstrual cycle, switching to positive feedback during the late-follicular phase.

Question 8

What occurs to the primary oocyte during ovulation?

Answer 8

Completes its 1st meiosis and produces a secondary oocyte

The secondary oocyte arrests in metaphase until fertilization.

Question 9

What hormone surge triggers ovulation?

Answer 9

LH surge

This is preceded by a rise in estradiol.

Question 10

What happens to the Graafian follicle after ovulation?

Answer 10

Collapses and transforms into corpus luteum

It releases progesterone and some estradiol.

Question 11

What is the function of progesterone during the menstrual cycle?

Answer 11

Maintains the endometrial lining and reduces contractility of reproductive organs

Essential for preparing the uterus for potential implantation.

Question 12

What is the proliferative phase of the endometrial cycle characterized by?

Answer 12

Hyperplasia and hypertrophy of the stromal and epithelial layer

Driven by estradiol.

Question 13

What occurs during the secretory phase of the endometrial cycle?

Answer 13

Endometrial glands become coiled and secrete carbohydrate-rich mucus

This phase prepares the endometrium for possible implantation.

Question 14

What is endometriosis?

Answer 14

Endometrial tissue in ectopic locations outside the uterus

Can lead to complications such as menstrual irregularities and infertility.

Question 15

What is a common characteristic of ovarian cysts?

Answer 15

Fluid-filled sac that forms on an ovary

Typically benign and may resolve spontaneously.

Question 16

What is the role of estradiol in uterine tubes during the menstrual cycle?

Answer 16

Maintains ciliated epithelium and increases motility

Important for the movement of the ovum.

Question 17

Fill in the blank: The corpus luteum regresses if there is no __________.

Answer 17

fertilization

This leads to the formation of corpus albicans.

Question 18

True or False: Progesterone decreases the spontaneous myometrial contractions.

Answer 18

True

This is important for preparing for implantation.

Question 19

What triggers the LH surge during the menstrual cycle?

Answer 19

Peak estradiol levels

The surge occurs 24-36 hours before ovulation.

Question 20

What is the physiological role of nitric oxide in female sexual response?

Answer 20

Facilitates clitoral vasocongestion and vaginal secretions

It is important for arousal.

Question 21

What are the histological features of endometrial hyperplasia?

Answer 21

Crowded endometrial glands, thickened epithelium, nuclear hyperchromasia

Can be classified as simple or complex based on architectural features.

Question 22

What is the definition of complex nonatypical hyperplasia of the endometrium?

Answer 22

Crowded endometrial glands with thickened hyperplastic layer of epithelium, nuclear enlargement, and nuclear hyperchromasia but no cytologic atypia

This condition suggests an abnormal growth pattern in the endometrial lining without the presence of atypical cells.

Question 23

What characterizes complex atypical hyperplasia of the endometrium?

Answer 23

Crowded endometrial glands with complex architectural features and cytologic atypia, including intraglandular papillary projections

This condition indicates a higher risk for progression to endometrial cancer.

Question 24

What are fibroids also known as?

Answer 24

Leiomyomas

These are benign tumors composed of smooth muscle from the myometrium.

Question 25

What are the typical features of fibroids?

Answer 25

Sharply circumscribed, firm, white surface, with intersecting fascicles of smooth muscle and no atypia

Fibroids often cause symptoms like menorrhagia (heavy bleeding).

Question 26

What is the primary symptom of fibroids?

Answer 26

Menorrhagia

This refers to heavy or prolonged menstrual bleeding.

Question 27

What are the phases of the menstrual cycle?

Answer 27

Follicular phase, late follicular phase, ovulation, luteal phase, menses

These phases involve complex hormonal changes and physiological responses in the female reproductive system.

Question 28

What is endometrial hyperplasia?

Answer 28

Increase in endometrial gland to stroma ratio, composed of typical or atypical cells

Atypical endometrial hyperplasia increases the risk of endometrial cancer.

Question 29

What can cause endometrial hyperplasia?

Answer 29

Excess estrogen stimulation, anovulatory cycles, exogenous estrogen administration, obesity, estrogen-producing ovarian conditions (e.g., PCOS)

These factors lead to an imbalance in hormonal regulation affecting the endometrium.

Question 30

What is the significance of cytologic atypia in endometrial conditions?

Answer 30

Indicates a potential for malignancy and higher risk of endometrial cancer

Cytologic atypia is a key feature distinguishing benign from potentially malignant endometrial hyperplasia.

Question 31

Fill in the blank: Endometrial hyperplasia is caused by excess ______ stimulation.

Answer 31

estrogen

Estrogen promotes the proliferation of endometrial tissue, leading to hyperplasia.

Question 32

True or False: There is no cytologic atypia in complex nonatypical hyperplasia.

Answer 32

True

This distinguishes it from atypical forms which do present cytologic atypia.