TBL 22

Question 1

What generates the ureteric bud?

Answer 1

Prior to its termination in the primitive urogenital sinus, the mesonephric duct generates the ureteric bud.

The proximal portion of the ureter and the portion of the mesonephric duct distal to the origin of the ureteric bud are absorbed into the posterior wall of the developing bladder.

Question 2

What forms the seminal vesicle?

Answer 2

After absorption of portions of the mesonephric duct and ureter into the bladder wall, the seminal vesicle is formed by an epithelial outgrowth near the end of the mesoneprhic duct.

Question 3

What forms the prostate gland?

Answer 3

epithelial outgrowth from the proximal urethra

Question 4

What becomes the ductus (vas) deferens?

Answer 4

mesonephric duct proximal to the duct of the seminal vesicle

Question 5

What forms the ejaculatory duct?

Answer 5

The ejaculatory duct terminates in the proximal urethra.

It is formed by ductus deferens + duct of the seminal vesicle

Proliferating prostatic parenchyma surrounds the ejaculatory duct and transforms the proximal urethra into the prostatc urethra.

Question 6

Where is the seminal vesicle located in the body?

Answer 6

sandwhiched between the rectum posteriorly and fundus of the bladder

Question 7

What happens to the ductus defeens and ureters on the posterior surface of the bladder?

Answer 7

The pair of ductus deferens cross the ureters anteriorly enroute to the deep inguinal ring in the anterolateral abdominal wall.

Question 8

What arteries supply the bladder?

Answer 8

vesicle arteries and branches from the vesicle arteries supply the prostate and seminal vesicles.

Question 9

What do periarterial plexuses on the branches of vesicle arteries do?

Answer 9

transport parasympathetic and sympathetic fibers from the inferior hypogastric plexuses to the bladder, prostate and seminal vesicles

Question 10

What do the prostatic venous plexus drain into? lateral sacral veins?

Answer 10

prostatic venous plexus –> internal iliac veins

lateral sacral veins –> internal vertebral venous plexus

Question 11

Where do lymph from the prostrate and seminal vesicles drain into?

Answer 11

internal iliac lymph nodes

Question 12

Why is benign hypertrophy of the prostate associated with nocturia (need to void in the night), dysuria (difficulty and/or pain during urination), and urinary frequency (sudden desire to urinate)? How can tumor cells from a prostatic adenocarcinoma metastasize vascularly to the brain?

Answer 12

An enlarged prostate projects into the urinary bladder and impedes urination by distorting the prostatic urethra.

Cancer cells metastasize both via lymphatic routes (intially to the internal iliac and sacral lymph nodes and later to distant nodes) and via venous routes (by way of the internal vertebral venous plexus to the vertebrae and brain).

Question 13

What does the prostatic stroma consist of?

Answer 13

Prostatic stroma consists of collagen fibers mixed with bundles of smooth muscle fibers.

Prostatic glands secrete into the prostatic urethra and sympathetic- mediated contraction of the stromal smooth muscle contributes to ejaculation.

Question 14

Describe the segments of the prostate.

Answer 14

MUSCULAR ANTERIOR zone

GLANDULAR CENTRAL zone around urethra and ejaculatory ducts
which tends to hypertrophy with advancing age

large PERIPHERAL GLANDULAR zone which is susceptible to inflammation and prostatic adenoc

Question 15

What happens to prostatic concretions with aging?

Answer 15

Prostatic concretions (mixtures of glandular secretions and degenerated secretory cells) appear in the acinar lumens.

secretory acini account for 20% of seminal fluid

Question 16

What is the role of acinar secretions?

Answer 16

White serous fluid that contains acid phosphatase, citric acid, zinc, prostate specific antigen, and other proteases and fibrolytic enzymes involved in the liquefaction of semen.

Question 17

What is the frequency of benign prostatic hypertrophy and how are its symptoms commonly treated?

Answer 17

It affects 30% of men older than 50 years. Its frequency and severity increase with aging.

The drugs used for treatment include alpha1- adrenergic receptor blockers, which inhibit the contraction of prostatic smooth muscle and may help alleviate symptoms.

Question 18

Why can plasma levels of prostate-specific antigen be elevated by a prostatic adenocarcinoma?

Answer 18

When you have cancer you have more of the glandular cells so you produce antigen.

Question 19

What does the interior of the seminal vesicle display after sectioning?

Answer 19

Each seminal vesicle contains a highly convoluted, tube-shaped gland.

Sectioning the long, convoluted tubular gland results in the vacuolated appearance of the seminal vesicles.

Elaborate folding of the mucosa creates a lumen of intercommunicating cavities of varying sizes. The lumen is surround by layers of smooth muscle and sympathetic contraction of the layers contribute to ejaculation.

Question 20

What percentage of seminal fluid does secretory epithelium account for?

Answer 20

70%

The main product of epithelium synthesize and secrete various substances including glycoproteins.

Question 21

What forms the broad ligament?

Answer 21

Parietal peritoneum that drapes over the urterus and urterine tubes

Question 22

What is the ovarian ligament? Suspensory ligament? Round ligament?

Answer 22

Ovarian ligament: fold of the broad ligament that tethers the ovaries to the uterus and forms the surface epithelium of the ovaries.

Suspensory ligament: elongation of the broad ligament that provide passage to ovarian vessels and accompanying nerves from the lateral pelvic wall

Round ligament: pass from the uterus to the deep inguinal rings

Question 23

Describe the uterus.

Answer 23

The uterus is centered in the pelvic cavity and the ovaries are positioned laterally midway to the lateral pelvic walls.

The body and rounded fundus superior to the ostia of the uterine tubes form the superior 2/3 of the uterus and cylindrical cervix forms the inferior 1/3.

It is anteverted onto the superior wall of the empty bladder thereby providing passive support to the uterus. The cervix is suspended from the wall of the pelvic cavity by the cardinal ligament. Passive support allows for cervical immobility.

Question 24

Where do the uterine and vaginal arteries arise from?

Answer 24

internal iliac artery.

The arteries are conveyed to the respective viscera by the cardinal ligament.

Question 25

What conditions contribute to prolapse of a retroverted uterus?

Answer 25

Instead of pressing the uterus against the bladder, incrased intra-abdominal pressure tends to push the retroverted uters, a solid mass positioned upright over the vagina into or even through the vagina.

A retroverted uterus is likely to prolapse. The sitution is exacerbated in the presence of a disrupted perineal body or with atrophic pelvic floor ligaments and muscles.

Question 26

Which pelvic structure must be identified to preclude its damage or obstruction during surgical ligation of the uterine artery?

Answer 26

Ureter

Question 27

What happens to the ovarian arteries?

Answer 27

After arising from the abdominal aorta, the ovarian arteries descend on the posterior abdominal wall to the suspensory ligament.

They supply the ovaries and distal uterine tubes and anastomose with branches of the uterine and vaginal arteries to provide collateral circulation for the ovaries, uterine tubes, uterus and vagina.

Question 28

Where do uterine veins drain?

Answer 28

internal iliac veins

Question 29

Where do lymph from the ovaries drain? uterine tubes, body and cervix?

Answer 29

ovaries –> lumbar lymph nodes

uterine tubes, uterine body, cervix –> internal iliac lymoh nodes

Question 30

Where are the ovaries, uterine tubes, fundus and body of the uterus, and cervix located in context of the pelvic pain line?

Answer 30

ovaries, uterine tubes, fundus, body of uterus –> above

cervix –> below

Question 31

How does cervical cancer metastasize to the bladder or the brain?

Answer 31

No peritoneum intervenes between the anterior cervix and the base of the bladder, cervical cancer may be spread by contiguity to the bladder.

Lymphogeneous (lymph borne) metastasis to external or internal iliac or sacral nodes.

Hematogenous (blood borne) metastasis may occur via iliac or via the internal vertebral venous plexus.

Question 32

How does regional anesthesia differ after injection of anesthetic agents into the subarachnoid space at L3/L4 (spinal anesthesia) and after a caudal epidural block? Why can a severe headache occur only with the spinal anesthesia?

Answer 32

Spinal anesthesia: anesthetic is introduced with a needle into the spinal subarachnoid space at L3-L4 vertebral level, produces complete anesthesia inferior to approximately the waist level. All sensation (even those uterine contraction) are temporarily eliminated. Because the anesthetic agent is heavier than cerebrospinal fluid, it remains in the inferior spinal subarachnoid space while the patient is inclined. The anesthetic agent circulates into the cerebral subarachnoid space in the cranial cavity when the patient lies flat following delivery so severe headache is common sequel to anesthesia.

Caudal epidural block: In the sacral canal, the anesthesia bathes the S2-S4 spinal nerve roots (pain fibers from the uterine cervix, superior vagina and afferent fibers from the pudendal nerve). Lower limbs are not affected. Pain fibers from the uterine body (superior to the pelvic pain line) ascend to the inferior thoracic-superior lumbar levels. These and the fibers superior to them are not affected so the mother is aware of her uterine contractions. With epidural anesthesia, no “spinal headache” happens because the vertebral epidural space is not continuous with cranial epidural space.

Question 33

How do the bilateral gonads form?

Answer 33

They form in the intermediate mesoderm medial to the mesonephros.

Initially appear as a pair of longitudinal genital ridges.

Epiblast derived germ cells pass through the primitive streak and temporarily reside among endodermal cells in the yolk sac wall –> germ cells migrate along the dorsal mesentery of the hindgut to the genital ridges –> genital ridge epithelia invaginate to form primitive sex cords that characterize the indifferent gonads

Then: females –> sex cords degenerate and follicular cells formed by continued proliferation of the surface epithelium surround germ cell derived oogonia to form the primary follicles –> make indifferent gonads into ovaries

Question 34

What prevents indifferent gonad differentiation in the genital ridges?

Answer 34

If primordial germ cells fail to reach the ridges, the gonads will not develop.

Question 35

What happens to the ovaries during degeneration of the mesonephros?

Answer 35

they descend from their upper lumbar origins into the pelvic cavity

Question 36

What forms the mullerian or paramesonephric ducts?

Answer 36

longitudinal invaginations of the gonadal ridge epithelia form the mullerian ducts that course parallel to the mesonephric ducts.

The proximal ends of the paired paramesonephric ducts open directly into the peritoneal cavity.

Question 37

What forms the uterine canal? What does the uterine canal transform into?

Answer 37

ovarian dissension into the pelvis moves the middle portions of the paramesonephric ducts mediocaudally and their distal portions fuse in the midline to form the uterine canal

progressive growth transforms the uterine canal into the fundus, body and cervix of the uterus

Question 38

What happens to the proximal and middle portions of the paramesonephric ducts?

Answer 38

form the uterine tubes that perforate the wall of the uterine body and thereby establish continuity of the uterine lumen with the peritoneal cavity.

Question 39

What happens to mesonephric duct in females?

Answer 39

other than the distal portion of the mesonephric duct that is absorbed into the wall of the bladder the mesonephric ducts degenerate and disappear in females

Question 40

What happens to the paramesonephric ducts in males?

Answer 40

they completely regress by testicular production of mullerian inhibiting substance (MIS)

in females, persistance of the paramesonephric ducts results from the lack of MIS and degernation of the mesonephric ducts results from the absence of testosterone production.

Question 41

Why can peritonitis cause salpingitis and why is the latter a major cause of female infertility?

Answer 41

Since the female genital tract communicates with the peritoneal cavity through the abdominal ostia of the uterine tubes, infections of the vagina, uterus and tubes may result in peritonitis. Conversely, inflammations of a tube (salpingitis) may result from infections that spread from the peritoneal cavity.

A major cause of infertility in women is blockage of the uterine tubes, often a result of salpingitis.

Question 42

Why is primary peritonitis rare in females?

Answer 42

The female has an effective protective mechanism for the female reproductive tract.

1. mucous plug: blocks the external os (opening) of the uterus to most pathogens but not to sperms
2. covering of the peritoneum: makes watertight end-to-end anastomoses of intraperitoneal organs.

Question 43

What is a bicornate uterus?

Answer 43

The uterus has two horns entering a common vagina.

Question 44

At birth, how many follicles do the ovaries contain?

Answer 44

400,000

Question 45

What is germinal epithelium?

Answer 45

It is actually a peritoneal fold that forms the ovarian surface epithelium, which lacks germinal function but accounts for 90% of ovarian cancers.

Question 46

How are mature (Graafian) follicles made? What happens to the mature follice?

Answer 46

primary follicles –> secondary follicles during each menstrual cycle

several cycles are required for the differentiation of secondary follicles into Graafian follicles

during each cycle, one mature follicle normally ovulates and that follicle becomes a CORPUS LEUTUM. If pregnancy does not occur, the corpus luteum degenerates and is replaced by a fibrous scar called a CORPUS ALBICANS.

Mature follicles that fail to ovulate become ATRETIC (degenerating) follicles.

Question 47

When does atresia of the follicles happen?

Answer 47

It begins at birth so by puberty, the number of primary follicles is reduced to about 40,000. After puberty, atresia remains prevalent in all follicular stages and typically about 400 follicles ovulate between puberty and menopause.

Question 48

What happens to atretic follicles?

Answer 48

Like the corpus albicans, the atretic follicles also form scar tissue that is mostly removed by macrophages and restored as ovarian stroma by fibroblasts.

Question 49

What differentiates secondary follicles from primary ones?

Answer 49

Granulosa cells are derived by FSH-mediated proliferation of follicular cells, which transform primary follicles into secondary ones.

Question 50

Describe the secondary follicle.

Answer 50

In secondary follicles, multiple layers of granulosa cells surround the oocyte.

Granulosa cells are surrounded by several layers of stromal cell-derived theca cells.

Granulosa cells and theca cells secrete intermittent pools of follicular fluid, which contain growth factors and estrogen.

Question 51

How are secondary follicles transformed into Graafian follicles?

Answer 51

Coalescence of follicular fluid creates an antrum to make Graafian follicle.

Question 52

What is a corona radiata?

Answer 52

It is a cluster of granulosa cells that surrounds the oocyte and protrudes into the lumen of the antrum.

Question 53

What does FSH do? What about LH?

Answer 53

FSH: stimulates the granulosa cells and theca cells of secondary and mature follicles to release estrogen into the blood stream and at the midpoint of the menstrual cycle, high estrogen blood levels stimulate LH release from the pituitary.

LH: is essential for ovulation and the Graafian follicle receiving the highest dose of LH undergoes ovulation. (Remember that several Graafian follicles develop but only one ovulates at midcycle (day 14 of the typical 28-day menstrual cycle). LH transforms both the granulosa cells and theca cells into luteal cells, which constitute the corpus luteum. It also causes luteal cells to release progesterone into the blood stream.

Question 54

What does progesterone do?

Answer 54

Around day 25, high progesterone blood levels inhibit LH release from the pituitary. Decreased levels of circulating LH causes degenerative transformation of the corpus luteum into the fibrous albicans.

Question 55

What is the importance of the open ends of the uterine tubes?

Answer 55

The open ends of the tubes provide continuity of the uterine lumen with the peritoneal cavity.

Question 56

What are fimbria?

Answer 56

Fimbria are finger-like projections from the end of the uterine tube. During ovulation, fibria closely surround the ovary thereby expediting tubular uptake of the oocyte and corona radiata.

Question 57

How long are the oviducts and what is special about their ampullary portion?

Answer 57

Oviducts are 12-15 cm long.
The ampullary portion of the oviducts have extensive folding of the mucosa.

Bundles of smooth muscle in the ampullary wall contribute to peristaltic movement of a fertilized oocyte (zygote) toward the uterus. Epithelium of the ampullary portion of the uterine tubes contain ciliated cells and secretory cells

Question 58

What is the function of ciliated cells and secretory cells from the ampulla?

Answer 58

Ciliated: transport of oocytes from upper to lower ends of fallopian tubes

Secretory: synthesize and secrete glycoproteins to provide nutrients to oocytes

Question 59

What is the frequency of tubal pregnancies and why can a ruptured tubal pregnancy be incorrectly diagnosed as acute appendicitis?

Answer 59

Tubal pregnancy is the most common type of ectopic gestation. It occurs in approximately 1/250 pregnancies in North America.

On the right side, the appendix lies close to the ovary and uterine tube. In both cases, the parietal peritoneum is inflamed in the same general area and the pain is referred to the right lower quadrant of the abdomen.

Question 60

What pierces the broad ligament covering the ovary during ovulation?

Answer 60

oocyte and corona radiata

If the fimbriae of the uterine tube fail to enclose the ovary, the ovulated cells could enter the peritoneal cavity.

Question 61

What is the endometrium and myometrium?

Answer 61

endometrium: uterine mucosa
myometrium: multiple longitudinal layers of smooth muscle that occupy most of the uterine wall.

Question 62

What is the most common tumor in the female pelvis and what is its primary symptom?

Answer 62

Leiomyomas, also known as fibroids are benign tumors of the uterus that arise as localized hyperplasia of smooth muscle cells of the myometrium.Usually occur before menopause and as a result of endocrine imbalance.

A common symptom is excessive and prolonged bleeding at menstruation.

Question 63

What is the probable pathogenesis of endometriosis?

Answer 63

Endometriosis: common gynecologic disease in which endometrial tissue appears at unusual locations in the lower abdomen and pelvis.

happens when endometrial cells peel off the uterine lining during the menstrual cycle and migrate via fallopian tubes to the peritoneal cavity. subsides after menopause when estrogen stimulation decreases.

Question 64

What arteries supply the myometrium? endometrium?

Answer 64

myometrium: large blood vessels are from the uterine artery

endometrium: straight arteries supply the basal layer
spiral arteries supply the larger functional layer

Question 65

Describe the menstrual cycle until day 14.

Answer 65

Day 1-4: menstrual phase of the cycle that results in shedding of the endometrial functional layer

Day 5: proliferative phase that under the influence of estrogen the unshed basal layer restores the functional layer

Day 14: invaginaltion of simple columnar epithelium reforms the uterine glands and progressive elongation of the glands within the proliferating lamina propia in basal layer is complete

Question 66

Describe the secretory phase of the menstrual cycle.

Answer 66

1. Corpus luteum-derived progesterone stimulates the endometrial glandular cells to secrete glycogen and glycoproteins into the glandular lumens. Lumens become progressively distended by secretions and become sacculated.
2. Progesterone induces vasodilation of the spiral arteries and the resulting increase in capillary blood flow creates mild edema in the lamina propia. During the secretory phase of the cycle, the functional layer is readied for potential zygote implantation.
3. During the end of phase, high progesterone levels inhibit LH release from the pituitary and in the absence of zygote implantation, reduced LH leads to a decrease in progesterone blood levels.
4. This decrease results in vasoconstriction of the spiral arteries and the resulting ischemia induces shedding of the functional layer as menses.

Question 67

Which pituitary and ovarian hormones induce the proliferative and secretory phases of the menstrual cycle and how do endometrial changes characterize each phase?

Answer 67

pituitary: LH and FSH
ovarian: estrogen and progesterone

endometrial changes: functional layer sheds and grows?

Question 68

What is the cervix?

Answer 68

It is the cylindrical end of the uterus that opens into the vagina.

Question 69

What happens to the mucosa of the proximal cervix (endocervix) during menstrual cycle?

Answer 69

proliferative phase: resembles endometrium at the end of this phase

secretory and menstrual phase: remains unaltered

Question 70

What is the exocervix?

Answer 70

It is the distal portion of the cervix that opens into the vagina and nonkeratinized stratified squamous epithelium lines it.

Question 71

What is the clinical relevance of the epithelial transformation at the junction of the endocervix and exocervix?

Answer 71

It is subject to tumor formation and is the site of most cervical carcinomas.

Question 72

What are nabothian cysts?

Answer 72

The epithelium has glandular invaginations that are large and more bunched than those in the body of the uterus and that secrete mucus. When these glands become occluded and dilated, follicles known as nabothian cysts form.

Question 73

How does the incidence of squamous cell carcinoma and adenocarcinoma differ in the cervix?

Answer 73

squamous cell carcinoma: 90%. exocervix. can be found through pap smears.

adenocarcinoma: 10%