Unit 3 Module 2 UP&F Phys (Exam 2) Flashcards
What is one of the most important determinants of maternal/fetal gas exchange?
A) Placental weight
B) Uterine perfusion
C) Fetal heart rate
D) Amniotic fluid volume
B) Uterine perfusion
Slide 4
By term, uterine blood flow is approximately:
A) 300 ml/min
B) 500 ml/min
C) 700 ml/min
D) 1000 ml/min
C) 700 ml/min
Slide 4
Uterine blood flow at term accounts for approximately what percentage of total maternal cardiac output?
A) 5%
B) 8%
C) 10%
D) 12%
D) 12%
Slide 4
The uterine perfusion system is characterized as a ________ circuit due to systemic vasodilation.
A) Low resistance
B) High resistance
C) Moderate resistance
D) No resistance
A) Low resistance
Slide 5
Which of the following contribute to high uterine blood flow? (Select 2)
A) Increased blood volume
B) Decreased cardiac output
C) Increased vascular resistance
D) Increased cardiac output
A) Increased blood volume
D) Increased cardiac output
Slide 5
The uterine arterial bed is maximally dilated at ________.
A) The first trimester
B) The second trimester
C) Term
D) Postpartum
C) Term
Slide 5
What is the primary source of uterine blood flow?
A) Ovarian arteries
B) Uterine arteries
C) External iliac arteries
D) Femoral arteries
B) Uterine arteries
slide 6
The uterine arteries branch from which major vessel?
A) Aorta
B) External iliac arteries
C) Internal iliac arteries
D) Renal arteries
C – Internal iliac
Aka - hypogastric arteries
Slide 6
The secondary source of uterine blood flow comes from which arteries?
A) Ovarian arteries
B) Femoral arteries
C) Pudendal arteries
D) Inferior epigastric arteries
A) Ovarian arteries
Slide 6
The ovarian arteries branch directly from the:
A) Inferior vena cava L5
B) Aorta at L4 level
C) Inferior mesenteric artery at L3
D) Renal arteries L1-L2
B) Aorta at L4 level
Slide 6
What percentage of uterine blood flow passes through the intervillous space?
A) 10-30%
B) 40-60%
C) 70-90%
D) 95-100%
C) 70-90%
Slide 8
The primary function of the intervillous space is to allow the exchange of ______ and ______ between maternal and fetal blood.
A) Gas; nutrients
B) Carbon dioxide; amniotic fluid
C) Red blood cells; nutrients
D) Gas; hemoglobin
A) Gas; nutrients
Slide 8
True or False
The uteroplacental circulation is a low resistance system
True
slide 8
Uterine blood flow (UBF) is determined by the ratio of uterine perfusion pressure (UPP) to ______.
A) Maternal heart rate
B) Uterine vascular resistance
C) Fetal hemoglobin concentration
D) Uteroplacental oxygen consumption
B) Uterine vascular resistance
UBF = UPP/UVR
Slide 9
Uterine perfusion pressure (UPP) is calculated as uterine arterial pressure (UAP) minus ______.
A) Umbilical venous pressure (UVP)
B) Intervillous space pressure (ISP)
C) Uterine venous pressure (UVP)
D) Placental resistance (PR)
C) Uterine venous pressure
UPP = UAP - UVP
Slide 9
Why is uterine blood flow highly dependent on maternal blood pressure?
A) It lacks autoregulation
B) It has a high resistance system
C) Fetal circulation directly controls uterine flow
D) Uterine venous pressure is greater than arterial pressure
A) It lacks autoregulation
Slide 9
In a normal, healthy pregnancy, uterine blood flow exceeds the minimal demand for ______.
A) Fetal glucose metabolism
B) Placental circulation
C) Intervillous space expansion
D) Fetal oxygenation
D) Fetal oxygenation
slide 9
Which of the following is a cause of decreased uterine blood flow?
A) Increased uterine arterial pressure
B) Decreased uterine vascular resistance
C) Increased uterine venous pressure
D) Increased cardiac output
C) Increased uterine venous pressure
UPP = UAP - UVP
Slide 10
What happens when uterine arterial pressure decreases?
A) Uterine blood flow increases
B) Uterine blood flow decreases
C) Uterine vascular resistance increases
D) Uterine venous pressure decreases
B) Uterine blood flow decreases
UPP = UAP - UVP
Slide 10
Uterine blood flow is reduced when uterine vascular resistance is ______.
A) Increased
B) Decreased
C) Unchanged
D) Not related to vascular resistance
A) Increased
UBF = UPP/UVR
Slide 10
Decreased Uterine Arterial Pressure
To avoid decreased uterine arterial pressure d/t aortocaval compression, pregnant patients should NOT be placed in a ______ position.
A) Trendelenburg
B) Prone
C) Left lateral
D) Supine
D) Supine
Slide 11
At what gestational age can aortocaval compression potentially begin to affect uterine blood flow?
A) 4-6 weeks
B) 8-10 weeks
C) 13-16 weeks
D) 20-24 weeks
C) 13-16 weeks
Slide 11
Which of the following factors can contribute to decreased uterine arterial pressure?
(Select 3)
A) Hypovolemia
B) Sitting positioning
C) Dehydration
D) Maternal hypertension
E) Hemorrhage
A) Hypovolemia
C) Dehydration
E) Hemorrhage
Important to get ahead of these with fluid bolus/ vasoconstrictors
Slide 11
Neuraxial anesthesia can cause hypotension by inducing a ______ blockade.
A) Sympathetic
B) Parasympathetic
C) Neuromuscular
D) Sensory
A) Sympathetic
Slide 12