Basic Science & Physiology Flashcards
Name 3 types of shock most likely to be seen in the obgyn population.
- Cardiogenic shock
- Hypovolemic shock
- Septic shock
(4. Neurogenic shock unlikely)
SOGC 115
What are the 3 vital organs that the body will try to perfuse by several compensation mechanisms?
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
What is the mortality rate of patients in severe hemorrhagic shock?
30%
SOGC 115
In healthy patients, at what hgb level will oxygen-carrying capacity start to be compromised?
less than 60-70g/L
SOGC 115
Within the ovary, which cells do LH and FSH bind to?
Theca and granulosa cells
Williams gyn p.334
How many carbon rings do estrogen molecules have?
18-carbon rings
Williams gyn p.336
Which steroid hormone contains 19-carbon rings?
Androgens
21-carbon ring = progestins, mineralocorticoids and glucocorticoids
Williams gyn p.336
Name 3 locations where sex steroid hormones are synthesized.
Gonads
Adrenal glands
Placenta
Williams gyn p.336
What is the primary estrogen found during reproductive years and where does it come from?
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
What will cause an increase in SHBG? (3)
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
At what stage in the cell division process do the primary oocytes stop?
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
Name the generation of progestogens.
- Levonorgestrel
- Drospirenone
- Desogestrel
- Norethindrone
Which one of the above is derived from spironolactone?
- 2nd generation
- 4th generation
- 3rd generation
- 1st generation
Each generation become progressively less androgenic.
Drospirenone is derived from spironolactone.
William’s gyn p. 363
What embryological structure becomes the Fallopian tubes, uterus and upper vagina?
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
By how many weeks is the vaginal canalization complete in the fetus?
20 weeks
William’s Obs Chapter 3
What is the remnant of the mesonephric duct called in women?
Gartner duct cyst
William’s Obs Chapter 3
What are common anomalies associated with MRKH syndrome?
MRKH = Mayer-Rokitansky-Kuster-Hauser Syndrome
Commonly associated with anomalies of the renal, skeletal and auditory systems
William’s Obs Chapter 3
What is the incidence of uterine abnormalities?
0.4-5%
William’s Obs Chapter 3
What is OHVIRA syndrome?
Class 3 uterine anomaly
- 2 uteruses and cervixes
- Obstructed hemivagina
- Ipsilateral renal agenesis
William’s Obs Chapter 3
In a pregnant woman, by how many weeks will the uterus be too large to remain in the pelvis?
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
What are Theca-Lutein cysts?
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
By 32-34 weeks of pregnancy, by how much did the blood volume increase?
40-45%
After 1st trimester, increases by 15%. Peak at 32-34 weeks.
William’s Obs Chapter 4
Clotting factors concentrations are generally increased in pregnancy except for 2, what are they?
Factors XI and XIII
William’s Obs Chapter 4
Do protein C and S levels increase or decrease during pregnancy?
Decrease
William’s Obs Chapter 4
How does cardiac output increase during pregnancy? (2)
- Reduced systemic vascular resistance
- Increase heart rate (by about 10 bpm)
Increase in cardiac output will begin at 5th week of pregnancy
William’s Obs Chapter 4
Name two reasons why GFR (glomerular filtration rate) is increased in pregnancy.
- Hypervolemia-induced hemodilution lowers protein concentration and oncotic pressure of plasma entering the glomerular microcirculation
- 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
