Basic Science & Physiology

Question 1

Name 3 types of shock most likely to be seen in the obgyn population.

Answer 1

1. Cardiogenic shock
2. Hypovolemic shock
3. Septic shock
   (4. Neurogenic shock unlikely)

SOGC 115

Question 2

What are the 3 vital organs that the body will try to perfuse by several compensation mechanisms?

Answer 2

1) Central nervous system
○ CNS able to function despite hypoperfusion until MAP below 60-70mm Hg
○ As hypovolemia worsens, mild agitation and confusion will progress to lethargy and obtundation
2) Cardiac system
○ Can compensate for early shock
○ Early hypovolemia associated with reflex tachycardia and increased stroke volume
○ Further hypoperfusion will lead to myocardial dysfunction, ischemia and failure
○ May experience chest pain, dyspnea, etc
3) Renal system
○ Can compensate for losses by activation of renin-angiotensin-aldosterone system
○ Reversible renal injury associated with low urine sodium concentration and high urine osmolarity

SOGC 115

Question 3

What is the mortality rate of patients in severe hemorrhagic shock?

Answer 3

30%

SOGC 115

Question 4

In healthy patients, at what hgb level will oxygen-carrying capacity start to be compromised?

Answer 4

less than 60-70g/L

SOGC 115

Question 5

Within the ovary, which cells do LH and FSH bind to?

Answer 5

Theca and granulosa cells

Williams gyn p.334

Question 6

How many carbon rings do estrogen molecules have?

Answer 6

18-carbon rings

Williams gyn p.336

Question 7

Which steroid hormone contains 19-carbon rings?

Answer 7

Androgens

21-carbon ring = progestins, mineralocorticoids and glucocorticoids

Williams gyn p.336

Question 8

Name 3 locations where sex steroid hormones are synthesized.

Answer 8

Gonads
Adrenal glands
Placenta

Williams gyn p.336

Question 9

What is the primary estrogen found during reproductive years and where does it come from?

Answer 9

Estradiol (E2) is the primary estrogen found during reproductive years.
It comes from direct production from the granulosa cell of developing follicles in the ovary and from conversion from the less potent estrone.

Williams gyn p.337

Question 10

What will cause an increase in SHBG? (3)

Answer 10

Hyperthyroidism
Pregnancy
Elevated estrogen levels

In turn, SHBG will decrease when elevated androgens, progestins, growth hormones, insulin and corticoids. Central body fat = obesity will also blunt SHBG expression.

Williams gyn p.338

Question 11

At what stage in the cell division process do the primary oocytes stop?

Answer 11

Arrested at prophase during the first meiotic division.

Meiosis 1 completed with LH surge
Meiosis 2 begins and is arrested during meta phase
Meiosis 2 completed if ovum fertilized

William’s gyn p.348

Question 12

Name the generation of progestogens.

1. Levonorgestrel
2. Drospirenone
3. Desogestrel
4. Norethindrone

Which one of the above is derived from spironolactone?

Answer 12

1. 2nd generation
2. 4th generation
3. 3rd generation
4. 1st generation

Each generation become progressively less androgenic.

Drospirenone is derived from spironolactone.

William’s gyn p. 363

Question 13

What embryological structure becomes the Fallopian tubes, uterus and upper vagina?

Answer 13

Mullerian ducts, also known as paramesonephric ducts

Uterus is formed by 10 weeks but union of two Mullerian ducts. Fusion starts at the middle, then extends cephalo-caudally.

William’s Obs Chapter 3

Question 14

By how many weeks is the vaginal canalization complete in the fetus?

Answer 14

20 weeks

William’s Obs Chapter 3

Question 15

What is the remnant of the mesonephric duct called in women?

Answer 15

Gartner duct cyst

William’s Obs Chapter 3

Question 16

What are common anomalies associated with MRKH syndrome?

Answer 16

MRKH = Mayer-Rokitansky-Kuster-Hauser Syndrome
Commonly associated with anomalies of the renal, skeletal and auditory systems

William’s Obs Chapter 3

Question 17

What is the incidence of uterine abnormalities?

Answer 17

0.4-5%

William’s Obs Chapter 3

Question 18

What is OHVIRA syndrome?

Answer 18

Class 3 uterine anomaly

• 2 uteruses and cervixes
• Obstructed hemivagina
• Ipsilateral renal agenesis

William’s Obs Chapter 3

Question 19

In a pregnant woman, by how many weeks will the uterus be too large to remain in the pelvis?

Answer 19

By 12 weeks.
They also usually will rotate to the right (dextrorotation) cause by rectosigmoid on the left side of the pelvis

William’s Obs Chapter 4

Question 20

What are Theca-Lutein cysts?

Answer 20

Benign cysts in pregnancy that result from exaggerated physiological follicle stimulation.

• Often bilateral
• Associated with very elevated bHCG
• Maternal virilization can occur in 30% of women (although not documented in fetuses)

William’s Obs Chapter 4

Question 21

By 32-34 weeks of pregnancy, by how much did the blood volume increase?

Answer 21

40-45%

After 1st trimester, increases by 15%. Peak at 32-34 weeks.

William’s Obs Chapter 4

Question 22

Clotting factors concentrations are generally increased in pregnancy except for 2, what are they?

Answer 22

Factors XI and XIII

William’s Obs Chapter 4

Question 23

Do protein C and S levels increase or decrease during pregnancy?

Answer 23

Decrease

William’s Obs Chapter 4

Question 24

How does cardiac output increase during pregnancy? (2)

Answer 24

1. Reduced systemic vascular resistance
2. Increase heart rate (by about 10 bpm)

Increase in cardiac output will begin at 5th week of pregnancy

William’s Obs Chapter 4

Question 25

Name two reasons why GFR (glomerular filtration rate) is increased in pregnancy.

Answer 25

1. Hypervolemia-induced hemodilution lowers protein concentration and oncotic pressure of plasma entering the glomerular microcirculation
2. Renal plasma flow increases by approximately 80%

GFR increases by 25% by the second week of conception and by 50% at the beginning of the second trimester.

William’s Obs Chapter 4