Download physio unit 4 Ch22 Ch 23

Physio Unit IV
Ciculation Learning Objectives
1.
What’s the difference between injury current and circus movement?
 Circus movement tends to develop in enlarged cardiac chambers, whereas injury current has
to do with ischemic tissues being unable to repolarize
2.

Why does coronary steal syndome happen?
Anastomotic channels don’t dilate as well as the rest of the coronary circulation

Why is beta receptor stimulation bad for patients with acute MI?
Beta receptors will cause the heart to be with enhanced furor
3.
4.
What’s the major cause of death after an MI?: rupture, fibrillation, low output, or edema? And
by that I don’t mean “sudden cardiac death” (Pathology), which is most often caused by lethal
arrhythmias.
 Decreased cardiac output is the major cause of death after MI
Chapter 22
5. What is decompensated heart failure? How is this different from cardiogenic shock? How do
you treat cardiogenic shock?
 Inability of the heart to pump sufficient blood to make the kidneys excrete fluid at the
necessary rate; treat with diuretics and digitalis
i. Edema and overstretch of the heart diminish its effectiveness despite increasing
right atrial pressure; sympathetic nerves also get depleted of NTs
 In cardiogenic shock the heart can’t pump enough to keep the body tissues (and itself!) alive
i. Blood volume expanders, vasoconstrictors, and digitalis
6. What causes systemic edema in HF? What are the mechanisms (4)? What causes ANP release?
 Fluid retention by kidneys increases hydrostatic pressure
 Reduced arterial pressure, intense sympathetic stimulation constricts afferent arterioles in
kidney, RAAS activation + ADH release
 Stretch of atrial walls
7.

How do you treat acute pulmonary edema due to late-stage HF?
Tourniquets to sequester blood in the veins, furosemide, oxygen, and digitalis

What does a cardiac reserve of 100% mean?
This means you can increase output by 100%, NOT that you can’t provide enough output for
extra activity
8.
9.
What does beriberi do?
 Weakens the heart and diminishes systemic vascular resistance (increases venous return)=>
high output cardiac failure
Chapter 23
10. What is the third heart sound? What is the fourth heart sound?


Blood rushing into the ventricles mid diastole
Only sometimes detected on phonograms; due to atrial contraction
11. What is the sound associated with regurgitation?
 blowing
12. What is the loudest murmur?
 Aortic stenosis—heard as a harsh “thrill”
13. Which murmurs are heard during systole?
 Ventricular septal defect, aortic stenosis, mitral regurgitation, PDA (both systole and diastole)
14. Which murmurs are heard during diastole only?
 Aortic regurgitation, mitral stenosis, tricuspid stenosis