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Flashcards in Cardiovascular Deck (137)
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0

Where does fetal erythropoiesis occur?

"Young Liver Synthesizes Blood"

Yolk sac (3-10 wk)
Liver (6 wk-birth)
Spleen (15-30 wk)
Bone marrow (22 wk+)

1

What are the three shunts in fetal circulation?

1) Ductus venosus
Umbilical vein (oxygenated) --> IVC

2) Foramen ovale
RA (oxygenated) --> LA

3) Ductus arteriosus
Pulmonary artery (deoxygenated from SVC) --> Aorta (after the great vessels)

2

What is used to keep a PDA open?
To close it?

PGE keeeeeps it open

Indomethacin closes it

3

What does the umbilical vein become?

Ligamentum teres hepatis
(within falciform ligament)

4

What do the umbilical arteries become?

Medial umbilical ligaments

5

What does the ductus arteriosus become?

Ligamentum arteriosum

6

What does the ductus venosus become?

Ligamentum venosum

7

What does the foramen ovale become?

Fossa ovale

8

What does the urachus become?

Median umbilical ligament

Urachus is part of the allantoic duct (portion between bladder & umbilicus)

9

What does the notochord become?

Nucleus pulposus of intervertebral disc

10

What does it mean to be right heart dominant vs. left?

Right dominant (85%) - the posterior descending artery arises from the RCA

Left dominant (8%) - the PD arises from the Left circumflex

Codominant (7%)

11

What heart chamber composes the back of the heart?
What can be seen with pathology?

The LA is the most posterior chamber. Enlargement can cause dysphagia (esophageal compression) or hoarseness (recurrent laryngeal)

12

Myocardial infarction:
What leads will show alterations?
What artery is infarcted?
Left lateral wall

Leads I, AVL, V5, V6

LCX or LCA infarction

13

Myocardial infarction:
What leads will show alterations?
What artery is infarcted?
Anterior

Leads: V2-V4

LAD

14

Myocardial infarction:
What leads will show alterations?
What artery is infarcted?
Septal

Leads: V1,V2

LAD

15

Myocardial infarction:
What leads will show alterations?
What artery is infarcted?
Inferior

Leads: II,III,AVF

PDA or RCA

16

What are the equations for Cardiac Output?

CO = Stroke Volume * HR

CO =
(O2 consumption rate)/(arterial O2 content - venous O2 content)

17

What are the equations for mean arterial pressure?

MAP = (2/3)Diastolic + (1/3)Systolic

MAP = CO x TPR

18

What factors increase myocardial O2 consumption?

^Afterload
^Contractility
^HR
^Heart size (wall tension)

19

How does blood pH affect potassium levels?

Potassium moves the opposite direction of protons across cell membranes in order to maintain charge.Thus:

Acidosis --> hyperkalemia
Alkalosis --> hypokalemia

20

What effect does insulin have on potassium?

INsulin causes K+ shift INto cells.

This is why DKA pts are hyperkalemic at first but may become hypokalemic with treatment. (Also because acidosis --> hyperkalemia).

21

How does acidosis decrease contractility?

H+ shifts into cardiac cells, so K+ shifts out --> hyperpolarization of the membrane

22

How are preload and afterload affected by dilating drugs?

vEnodilators decrease prEload

vAsodilators decrease Afterload

23

What can decrease contractility?

Beta blockade
CHF
Acidosis
Hypoxia/Hypercapnia
Non-dihydropyridine CCB's

24

What is the equation for ejection fraction?
What is a normal ejection fraction?

EF = (EDV - ESV)/EDV

Normal is >55%

25

What portion of the vasculature accounts for most of the resistance to flow?

Arterioles

26

What is the total resistance of vessels in series?
In parallel?

Series:
Total = R1 + R2 + R3. . .

Parallel:
1/Total = 1/R1 + 1/R2 + 1/R3. . .

27

What factors determine resistance?

Viscosity & vessel length increase resistance

Radius decreases resistance

28

What are the waves on a jugular venous pulse tracing?

a = RA contraction
c = RV contraction (valve bulges backward)
v = RA filling against closed tricuspid

29

What causes the dicrotic notch seen on aortic pressure tracings?

Transient backward flow back into the LV, which causes closure of the valve. The elastic recoil of the aorta can then exert its effects, causing an increase in pressure.