3: Anatomy and Physiology

Question 1

Name the bones of the pelvis.

Answer 1

1. two hip bones called the innominate bones (also known as ox coxae)
2. sacrum
3. coccyx

The innominate bones consist of the pubis, the ischium, and the ilium, all of which are fused together at the acetabulum. The ilium comprises the posterior and upper portion of the innominate bone, forming what is known as the iliac crest. It articulates with the sacroiliac joint posteriorly, and together with its ligaments is the major contributor to pelvic stability. The pubic bones articulate anteriorly with the symphysis pubis and, with their inferior angles from the descending rami, form the important bony landmark of the pubic arch. The ischial spines are bony prominences that are clinically important because they are used as landmarks when performing pudendal blocks and in other medical procedures such as sacrospinous ligament suspension. The ischial spines are also used to assess progression of fetal descent during childbirth.

Question 2

What does the iliac crest articulate with?

Answer 2

Sacroiliac joint posteriorly

Question 3

What provides the majority of pelvic stability?

Answer 3

The ilium comprises the posterior and upper portion of the innominate bone, forming what is known as the iliac crest. It articulates with the sacroiliac joint posteriorly, and together with its ligaments is the major contributor to pelvic stability.

Question 4

Which bones are used as landmarks when performing pudendal blocks and other medical procedures such as sacrospinal ligament suspension?

Answer 4

Ischial spines

Question 5

Which bones are used to assess progression of fetal descent during childbirth?

Answer 5

Ischial spines

Question 6

The _____ and the _____ shape the posterior portion of the pelvis.

Answer 6

The sacrum and the coccyx shape the posterior portion of the pelvis.

Question 7

The sacrum is formed by the fusion of the _____, which includes the important bony landmark of the sacral promontory, and joins the coccyx at the sacrococcygeal symphysis.

Answer 7

The sacrum is formed by the fusion of the five sacral vertebrae, which includes the important bony landmark of the sacral promontory, and joins the coccyx at the sacrococcygeal symphysis.

Question 8

The coccyx is formed by the fusion of _____, is usually movable, and is itself a key bony landmark.

Answer 8

The coccyx is formed by the fusion of four rudimentary vertebrae, is usually movable, and is itself a key bony landmark.

Question 9

The _____ constitutes the bony passageway through which the fetus must maneuver to be born vaginally.

Answer 9

The true pelvis constitutes the bony passageway through which the fetus must maneuver to be born vaginally.

Question 10

What is the best-known classification of the female pelvis and what characteristic is used for classification?

Answer 10

• Caldwell-Moloy
• Posterior segment of the inlet

Question 11

Name the 4 basic pelvic types.

Answer 11

1. Gynecoid
2. android
3. anthropoid
4. platypelloid

Question 12

T/F Most pelvises are one of the 4 main types.

Answer 12

False. Most pelvises are a mixture of types.

Question 13

Name the 3 pelvic support structures.

Answer 13

1. muscles and connective tissue of the pelvic floor
2. fibromuscular tissue of the vaginal wall
3. endopelvic connective tissue

Question 14

Where does the obturator internus muscle exit the pelvis?

Answer 14

Lesser sciatic foramen

Question 15

Pouch that lies superiorly to the perineal membrane.

Answer 15

Deep perineal space

Question 16

A sheet made up of dense fibrous tissue that spans the opening of the anterior pelvic outlet.

Answer 16

Perineal membrane (or urogenital diaphragm)

Question 17

The most important muscle of the pelvic floor.

Answer 17

Levator ani muscle

Question 18

The pubococcygeus, puborectalis, and iliococcygeus are the primary components making up what muscle?

Answer 18

Levator ani muscle

Question 19

The _____ or sphincter vaginae fibers form the sling around the vagina and originate from the posterior surface of the pubis; they insert in the perineal body.

Answer 19

The levator prostatae or sphincter vaginae fibers form the sling around the vagina and originate from the posterior surface of the pubis; they insert in the perineal body.

Question 20

The _____ are important in maintaining fecal continence; they originate from the posterior surface of the pubis and form a sling around the rectum.

Answer 20

The puborectalis fibers are important in maintaining fecal continence; they originate from the posterior surface of the pubis and form a sling around the rectum.

Question 21

The _____ originate from the posterior surface of the pubis and insert into the anococcygeal rapine.

Answer 21

The pubococcygeus fibers originate from the posterior surface of the pubis and insert into the anococcygeal rapine.

Question 22

The _____ originate from the obturator internus fascia and the ischium and insert into the anococcygeal rapine.

Answer 22

The iliococcygeus fibers originate from the obturator internus fascia and the ischium and insert into the anococcygeal rapine.

Question 23

The fan-shaped _____ lies anterior to the sacrospinous ligament, originates from the ischial spine, inserts into the lower part of the sacrum and coccyx, and works synergistically to aid the levator ani muscle.

Answer 23

The fan-shaped coccygeus muscle lies anterior to the sacrospinous ligament, originates from the ischial spine, inserts into the lower part of the sacrum and coccyx, and works synergistically to aid the levator ani muscle.

Question 24

The_____ contracts to cause erection of the clitoris during sexual arousal.

Answer 24

The ischiocavernous muscle contracts to cause erection of the clitoris during sexual arousal.

Question 25

The externally visible outer genitalia.

Answer 25

Vulva

Question 26

Name the components of the vulva.

Answer 26

1. Mons pubis
2. Labia minora
3. Labia majora
4. Clitoris
5. Urinary meatus
6. Vaginal opening
7. Corpus spongeosum erectile tissue (vestibular bulbs) of the labia minora and perineum

Question 27

The _____ is inside the labia minora and outside the hymen.

Answer 27

The vestibule is inside the labia minora and outside the hymen.

Question 28

On each side of the vestibule is a _____, which secretes lubricating mucus into the introitus during sexual excitement.

Answer 28

On each side of the vestibule is a Bartholin’s gland, which secretes lubricating mucus into the introitus during sexual excitement.

Question 29

The mound-like pad of fatty tissue that covers and protects the symphysis pubis.

Answer 29

Mons pubis

Question 30

They assist in keeping the vaginal introitus closed, which in turn helps prevent infection.

Answer 30

Labia majora

Question 31

Smaller, nonfatty folds covered by non-hair-bearing skin laterally and by vaginal mucosa on the medial aspect.

Answer 31

Labia minora

Question 32

What are normal colors for the labia?

Answer 32

1. Light pink
2. Dark pink
3. Shades of gray
4. Peach
5. Brown
6. Black

Question 33

The labia minora are usually more prominent in _____ and women who are _____.

Answer 33

The labia minora are usually more prominent in children** and women who are **postmenopausal.

Question 34

A sensitive organ that is typically described as the female homologue of the penis in the male.

Answer 34

Clitoris

Question 35

It is formed from the genital tubercle. It is 1.5 to 2 cm in length, consists of two crura and two corpora cavernosa, and is covered by a sensitive rounded tubercle known as the glans

Answer 35

Clitoris

Question 36

Organ that consists of two paired erectile chambers and is located at the superior portion of the vestibule.

Answer 36

Clitoris

Question 37

What is formed in part by the fusion of the upper part of the two labia minora?

Answer 37

Clitoral hood

Question 38

Which arteries provide blood supply to the clitoris?

Answer 38

Dorsal and clitoral cavernosal arteries

Question 39

Which 2 parts play a critical role in sexual activity?

Answer 39

1. Labia minora
2. Clitoris

Question 40

Age-associated female sexual dysfunction from decreased clitoral sensitivity may be associated with histologic changes in _____.

Answer 40

Age-associated female sexual dysfunction from decreased clitoral sensitivity may be associated with histologic changes in clitoral cavernosal erectile tissue.

Question 41

Periurethral glands which release mucus, form a triangular area of mucous membrane surrounding the urethral meatus from the clitoral glans to the vaginal upper rim or caruncle.

Answer 41

Skene’s glands (2 of them)

Question 42

The pea-sized vestibular glands are located at about the 4 and 8 o’clock positions in the vulvovaginal area, just beneath the fascia.

Answer 42

Bartholin’s glands

Question 43

Where are the 2-cm openings of the Bartholin’s glands?

Answer 43

They open into a groove between the labia minora and hymen.

Question 44

What type of cells make up Bartholin’s glands?

Answer 44

Columnar cells

Question 45

A short conduit, approximately 3 to 5 cm long, extending from the base of the bladder and exiting externally to the vestibule.

Answer 45

Urethra

Question 46

What type of cells make up the urethra?

Answer 46

The urethral mucosa is composed of stratified transitional epithelium near the urinary bladder; the rest of this structure is lined by a stratified squamous epithelium.

Question 47

A circular band of skeletal muscle that forms the sphincter urethrae, better known as the external urethral sphincter.

Answer 47

Urogenital diaphragm

Question 48

Paired organs that resemble a large almond in terms of their size and configuration.

Answer 48

Ovaries

Question 49

What is the approximate size of an ovary?

Answer 49

1.5 cm x 2.5 cm x 4 cm

Question 50

What is the approximate weight of an ovary?

Answer 50

3-6 grams

Question 51

The ovaries produce _____ and the sex hormones known as _____ and _____.

Answer 51

The ovaries produce gametes (also known as ova) and the sex hormones known as estrogen and progesterone.

Question 52

T/F The color and texture of sex organs change with a woman’s age and reproductive stage.

Answer 52

True

Question 53

Where are the ovaries in a nulliparous woman situated?

Answer 53

A shallow depression called the ovarian fossa, located on either side of the uterus in the upper pelvic cavity.

Question 54

The _____ is the principal supporting membrane of a woman’s internal genital organs, including the fallopian tubes and uterus.

Answer 54

The broad ligament is the principal supporting membrane of a woman’s internal genital organs, including the fallopian tubes and uterus.

Question 55

What are the 3 parts of an ovary?

Answer 55

1. Outer cortical region (cortex), which contains germinal epithelium with oogonia and ovarian follicles that number approximately 400,000 at the initiation of puberty.
2. Medullary region (medulla), which consists of connective tissue, myoid-like contractile cells, and interstitial cells.
3. Hilum, which is the point of entrance for all of the ovarian vessels and nerves.

Question 56

The nerve fibers to the ovaries innervate only the vascular networks, and not the _____.

Answer 56

The nerve fibers to the ovaries innervate only the vascular networks, and not the stroma.

Question 57

Paired narrow muscular tubes that extend approximately 10 cm from each cornu of the body of the uterus, outward to their openings near the ovaries.

Answer 57

Fallopian tubes

Question 58

Name the 4 segments of the fallopian tubes.

Answer 58

1. The pars interstitialis (intramural portion) penetrates the uterine wall. It contains the fewest mucosal folds, with the myometrium contributing to its muscularis.
2. The isthmus, the narrow segment adjacent to the uterine wall, contains few mucosal folds.
3. The middle segment, known as the ampulla, is the widest and longest segment. It contains extensive branched mucosal folds and is the most common site of fertilization.
4. The infundibulum, the funnel-shaped distal segment, opens near the ovary but is not attached to it (Katz, 2012). Very fine fingerlike fronds of its mucosal folds, known as fimbriae, project from the opening toward the ovary to help direct the oocyte into the lumen of the fallopian tube.

Question 59

How do the ova move down the fallopian tubes?

Answer 59

Cilia that cover the fallopian tubes.

Question 60

What are the 3 layers of the wall of the fallopian tube?

Answer 60

1. Mucosa (internal)
2. Muscularis (middle)
3. Serosa (outer)

Question 61

Which arteries supply blood to the fallopian tubes?

Answer 61

1. Ovarian artery
2. Uterine artery

Question 62

A muscular, inverted, pear-shaped, hollow, thick-walled organ that opens to the vagina at the cervix and then widens toward the top where the uterine tubes enter.

Answer 62

Uterus

Question 63

Name the 3 anatomic regions of the uterus.

Answer 63

1. Fundus
2. Body
3. Cervix

Question 64

When the _____ is empty, the uterus angles forward over it. As it fills, the uterus is lifted dorsally and may become retroflexed, pressing against the rectum.

Answer 64

When the bladder is empty, the uterus angles forward over it. As it fills, the uterus is lifted dorsally and may become retroflexed, pressing against the rectum.

Question 65

What is the approximate size of a nulliparous uterus?

Answer 65

8 cm long x 5 cm wide x 2.5 thick

Question 66

How much does a nulliparous uterus weigh?

Answer 66

40-50 grams

Question 67

What are the 3 layers of the uterine wall?

Answer 67

1. Endometrium
2. Myometrium
3. Serosa (adventitia)

Question 68

What type of cells make up the uterine mucosa?

Answer 68

Simple columnar epithelium supported by a lamina propria

Question 69

The _____ is the temporary layer at the luminal surface that responds to ovarian hormones by undergoing cyclic thickening and shedding.

Answer 69

The stratum functionale is the temporary layer at the luminal surface that responds to ovarian hormones by undergoing cyclic thickening and shedding.

Question 70

The_____ is the deeper, thinner, permanent layer that contains the basal portions of the endometrial glands.

Answer 70

The stratum basale is the deeper, thinner, permanent layer that contains the basal portions of the endometrial glands.

Question 71

This layer is retained during menstruation.

Answer 71

Stratum basale

Question 72

The _____ receives a double blood supply: uterine arteries that bifurcate into straight arteries to the stratum basale and coiled arteries to the functionalis.

Answer 72

The endometrium (of the uterus) receives a double blood supply: uterine arteries that bifurcate into straight arteries to the stratum basale and coiled arteries to the functionalis.

Question 73

During the cyclic shedding of the functionalis, which blood supply is retained and which is lost?

Answer 73

Straight arteries are retained while the coiled are lost.

Question 74

It is made mostly of dense connective tissue, is usually 2.5 to 3 cm in length, and is covered interiorly by a mucus-secreting ciliated epithelium at the upper regions and by stratified squamous epithelium at the bottom end.

Answer 74

Cervix

Question 75

The opening of the cervix into the vagina occurs at almost a _____ to the long axis of the vagina.

Answer 75

The opening of the cervix into the vagina occurs at almost a right angle to the long axis of the vagina.

Question 76

A thin-walled tube extending from the external vulva to the cervix

Answer 76

Vagina

Question 77

T/F The vagina touches the empty bladder on the ventral and superior surface.

Answer 77

True

Question 78

The internal mucosal layer of the vagina contains traverse folds, known as _____. This muscular canal extends from the midpoint of the cervix to its opening located between the urethra and the rectum. The mucous membrane lining the vagina and musculature is continuous with the uterus. The vaginal walls can be easily separated because their surfaces are normally moist, lubricated by a _____ vaginal fluid.

Answer 78

The internal mucosal layer of the vagina contains traverse folds, known as rugae**. This muscular canal extends from the midpoint of the cervix to its opening located between the urethra and the rectum. The mucous membrane lining the vagina and musculature is continuous with the uterus. The vaginal walls can be easily separated because their surfaces are normally moist, lubricated by a **basal vaginal fluid.

Question 79

To a much lesser degree than seen in the skin, this vaginal epithelium undergoes hormone-related cyclic changes, including slight _____ of the superficial cells during the menstrual cycle

Answer 79

To a much lesser degree than seen in the skin, this vaginal epithelium undergoes hormone-related cyclic changes, including slight keratinization of the superficial cells during the menstrual cycle

Question 80

Does the vaginal epithelium secrete mucus?

Answer 80

No, the epithelium has no glands, so it does not secrete mucus.

Question 81

How does the vaginal wall thicken? What does this do to vaginal ph?

Answer 81

Release of estrogen causes the epithelium to thicken, differentiate, and accumulate glycogen. Vaginal bacteria metabolize the glycogen to lactic acid, causing the typically low pH of the vaginal environment.

Question 82

Large, modified sebaceous glands contained within superficial fascia.

Answer 82

Breasts

Question 83

5 components of breasts.

Answer 83

1. Nipple
2. Lobes
3. Ducts
4. Fibrous tissue
5. Fatty tissue

Question 84

T/F The number of lobes determines breast size.

Answer 84

False. It is unrelated.

Question 85

How many lobes in each breast?

Answer 85

Each breast is composed of 12 to 20 lobes of glandular tissue.

Question 86

How many passages are there through the breast?

Answer 86

Each lobe empties into a single lactiferous duct, so there are 12-20 per breast (and just as many in the nipple).

Question 87

_____ ligaments connect the chest wall to the skin of the breast, giving the breast its shape and elasticity.

Answer 87

Cooper’s ligaments connect the chest wall to the skin of the breast, giving the breast its shape and elasticity.

Question 88

In a nonpregnant woman, does the fatty tissue or glandular tissue affect breast size?

Answer 88

Fatty tissue

Question 89

Pigmented area surrounding the nipple.

Answer 89

Areola

Question 90

The nipple and areola are made of _____ and feature a thick network of nerve endings.

Answer 90

The nipple and areola are made of smooth muscle fibers and feature a thick network of nerve endings.

Question 91

What protects and lubricates the nipple during lactation?

Answer 91

Oil-producing Montgomery’s glands

Question 92

Discuss the reproductive hormones responsible for breast development during puberty and lactation.

Answer 92

Prolactin (PRL) and growth hormone (GH) from the anterior lobe of the pituitary stimulate mammary gland development. These hormones are aided by human placental lactogen from the placenta, which stimulates the mammary gland ducts to become active during pregnancy. Estrogen promotes the growth of the gland and ducts, while progesterone stimulates the development of milk-producing cells. Prolactin, which is released from the anterior pituitary, stimulates milk production. Oxytocin, which is released from the posterior pituitary in response to suckling, causes milk ejection from the lactating breast.

Question 93

T/F Although the main flow moves toward the axilla and anterior axillary nodes, lymph drainage has been shown to pass in all directions from the breast.

Answer 93

True

Question 94

When do menstrual cycles begin and end?

Answer 94

Typically start 12-15 years of age and end 45-55.

Question 95

It is now believed that _____ is critically important in determining the onset of puberty and menstruation in young women.

Answer 95

It is now believed that body composition is critically important in determining the onset of puberty and menstruation in young women.

Question 96

Who tends to have an earlier onset of menarche?

Answer 96

The ratio of total body weight to lean body weight is probably the most relevant factor, and individuals who are moderately obese (i.e., 20–30% above their ideal body weight) tend to have an earlier onset of menarche.

Question 97

What is the “normal” menstrual cycle?

• Frequency
• Cycle variation over 12 months
• Duration of flow
• Amount of flow

Answer 97

1. Frequency: 21-35 days (pg 88) or 24-38 (pg 576)
2. Cycle variation over 12 months: Variation less than 20 days
3. Duration of flow: 4-6 days (though 2-8 days still considered normal. pg 88) or 4.5-8 days (pg 576)
4. Amount of flow Avg of 50mL (20-80 mL pg 88) or 5-80 mL (pg 576)

Question 98

When are menstrual cycles frequently irregular and why?

Answer 98

Menstrual cycles that occur during the first 1 to 1.5 years after menarche are frequently irregular due to the immaturity of the hypothalamic–pituitary–ovarian axis.

Question 99

The _____ controls anterior pituitary functions via the secretion of releasing and inhibiting factors.

Answer 99

The hypothalamus controls anterior pituitary functions via the secretion of releasing and inhibiting factors.

Question 100

The hypothalamus initially releases gonadotropin-releasing hormone (GnRH) in a pulsatile manner. On average, the frequency of GnRH secretion is once per _____ minutes during the early follicular phase, increases to once per _____ minutes during the middle of the menstrual cycle, and then decreases during the luteal phase.

Answer 100

The hypothalamus initially releases gonadotropin-releasing hormone (GnRH) in a pulsatile manner. On average, the frequency of GnRH secretion is once per 60 to 100 minutes during the early follicular phase, increases to once per 60 to 70 minutes during the middle of the menstrual cycle, and then decreases during the luteal phase.

Question 101

Oval-shaped, pea-sized pituitary gland that is located in a small depression in the sphenoid bone of the skull.

Answer 101

Pituitary gland

Question 102

What 7 hormones does the anterior pituitary gland synthesize?

Answer 102

1. Growth hormone (GH)
2. Thyroid-stimulating hormone (TSH)
3. Adrenocorticotropin (ACTH)
4. Melanocyte-stimulating hormone (MSH)
5. Prolactin (PRL)
6. Follicle-stimulating hormone (FSH)
7. Luteinizing hormone (LH)

Question 103

T/F The endometrium emulates the activities of the ovaries; thus whatever happens in the uterus during the menstrual cycle is precisely correlated with whatever is occurring in the ovaries.

Answer 103

True

Question 104

What are the objectives of the ovarian and endometrial cycles?

Answer 104

1. Ovarian: Produce an ovum.
2. Endometrial: Prepare a site to nourish and maintain the ovum if it becomes fertilized.

Question 105

What are the phases of the ovarian cycle?

Answer 105

1. Follicular phase
2. Ovulatory phase
3. Luteal phase

Question 106

What are the 3 phases of the endometrial cycle?

Answer 106

1. Proliferative phase
2. Secretory phase
3. Menstruation

Question 107

Almost all hormones are released in short pulses at intervals of _____ to _____ minutes throughout most of the menstrual cycle, with these pulses decreasing in frequency closer to menstruation. _____ hormones modulate the frequency and amplitude of the pulse, which varies throughout the cycle.

Answer 107

Almost all hormones are released in short pulses at intervals of 60** to **90** minutes throughout most of the menstrual cycle, with these pulses decreasing in frequency closer to menstruation. **Steroid hormones modulate the frequency and amplitude of the pulse, which varies throughout the cycle.

Question 108

T/F Although the presence of progesterone reduces the frequency of the hypothalamic GnRH pulses, the amount of LH released from the pituitary is proportionally increased to sustain the corpus luteum and the production of progesterone.

Answer 108

True

Question 109

What happens in the menstrual cycle in the absence of pregnancy?

Answer 109

The corpus luteum degenerates, progesterone levels decline, and menstruation occurs.

Question 110

When does folliculogensis begin and end?

Answer 110

During the last few days of the previous menstrual cycle and continues until the release of the mature follicle at ovulation.

Question 111

When are a cohort of primary follicles recruited?

Answer 111

Days 1-4 of menstrual cycle.

Question 112

Follicles that have enough _____ cells will develop receptors for estrogen and FSH on the cells of the granulosa layers, and LH receptors on the theca cells.

Answer 112

Follicles that have enough granulosa cells will develop receptors for estrogen and FSH on the cells of the granulosa layers, and LH receptors on the theca cells.

Question 113

What is the primary role of FSH?

Answer 113

Induce the development of increased receptors on the granulosa cells and thereby stimulate estrogen production.

Question 114

What is the preliminary role of LH?

Answer 114

Stimulate the cells’ production of androgen that will be converted to estrogen by the granulosa layers.

Question 115

When is one dominant follicle from the cohort of recruited follicles chosen to ovulate during the next menstrual cycle?

Answer 115

Days 5-7

Question 116

Dominant follicle.

Answer 116

Graafian follicle

Question 117

Contains the ovum and is surrounded by a layer of granulosa cells, which are themselves surrounded by the specialized theca interna and theca externa cells.

Answer 117

Graafian follicle

Question 118

What happens to the oocyte at ovulation?

Answer 118

1. Initially the nuclear membrane around the oocyte breaks down.
2. The chromosomes progress through the rest of the first meiotic division.
3. The egg moves on to the secondary stage.
4. Meiosis ceases at this time and will be initiated again only if the ovum is fertilized.

Question 119

When does the LH surge occur for more than 2/3 of women?

Answer 119

Around 3 a.m.

Question 120

When does ovulation primarily occur?

Answer 120

1. Morning during the spring months.
2. Evening during autumn and winter.
3. In the Northern Hemisphere, from July to February, approximately 90% of women will ovulate between 4 and 7 p.m.
4. During the spring, 50% of women will ovulate between midnight and 11 a.m.

Question 121

How long does the corpus luteum function after ovulation?

Answer 121

Approximately 8 days

Question 122

What does the corpus luteum become?

Answer 122

Corpus albicans

Question 123

They occur in preparation for implantation of the fertilized ovum.

Answer 123

Progressive mitotic growth of the deciduas functionalis in response to increasing levels of estrogen secreted by the ovary.

Question 124

T/F Menstruation results from vascular events.

Answer 124

False. The current theory suggests that menstruation is initiated by enzymatic autodigestion of the functional layer of the endometrium, which is triggered by estrogen–progesterone withdrawal. As estrogen and progesterone levels fall during the days prior to menses, lysosomal membranes become destabilized, such that the enzymes within them are released into the cytoplasm of the epithelial, stromal, and endothelial cells and into the intercellular space. These enzymes are proteolytic: They digest the cells surrounding them as well as surface membranes. Their actions result in platelet deposition, release of prostaglandins, vascular thrombosis, extravasation of red blood cells, and tissue necrosis in the vascular endothelium. Enzymatic action progressively degrades the endometrium and eventually disrupts the capillaries and venous system just under the endometrial surface, causing interstitial hemorrhage and dissolution of the surface membrane and allowing blood to escape into the endometrial cavity. This degeneration continues and extends to the functional layer of the endometrium, where rupture of the basal arterioles contributes to the bleeding.

Question 125

_____ initiate contractions of the uterine smooth muscle and sloughing of the degraded endometrial tissue, leading to menstruation.

Answer 125

Prostaglandins initiate contractions of the uterine smooth muscle and sloughing of the degraded endometrial tissue, leading to menstruation.

Question 126

What is menstrual fluid made of (4 things)?

Answer 126

1. desquamated endometrial tissue
2. red blood cells
3. inflammatory exudates
4. proteolytic enzymes

Question 127

When is cervical mucus scant and viscous?

Answer 127

After menstruation

Question 128

In late follicular phase, the quantity of cervical mucus increases _____ compared to the early follicular phase and can stretch to at least _____.

Answer 128

In late follicular phase, the quantity of cervical mucus increases 30-fold** compared to the early follicular phase and can stretch to at least **6 cm.

Question 129

What helps reduce infection risk at the time of possible implantation?

Answer 129

• After ovulation, when progesterone levels are high, the cervical mucus once again becomes thick, viscous, opaque, and decreased in amount.
• This thick mucus is hostile and impenetrable to the sperm.
• The increased viscosity also reduces the risk of ascending infection at the time of possible implantation.

Question 130

What happens to the cervix around ovulation?

Answer 130

1. The cervix becomes softer a few days prior and at ovulation.
2. The external cervical os everts prior to ovulation.

Question 131

T/F Menstrual blood contains clots.

Answer 131

False. Because some of the clotting factors ordinarily found in blood are lysed by lysosomal enzymes in the uterus, menstrual blood does not clot.