Test 4 Study Guide Part 1 Flashcards
What is the means by which LDL becomes oxidized (in atherosclerosis and inflamatory responses):
Endothelial cells oxidize LDL when they engulf LDL
Oxidized LDL (likely oxidized by endothelial cells) contributes to the inflamatory response in what way? Why does this occur?
Oxidative damage from LDL causes:
Migration of monocytes and lymphocytes into the tunica interna
monocytes -> macrophages.
Other events which progress atherosclerosis.
How effective have antioxidants been in treating atherosclerosis?
What are some common antioxidants?
Not very. Antioxidant drug: probucol Vitamin C Vitamin E Beta-carotene
A drug which is an antioxidant.
Probucol
What is the most common cause of myocardial ischemia (ischemia is poor oxygen supply):
Coronary atherosclerosis.
the build up must restrict blood flow
Myocardial ischemia:
- Causes pain in what two regions:
- What is referred pain?
- Where does it cause it?
- Causes pain in what two regions: Substernal pain Left shoulder and arm - What is referred pain? pain felt in a part of the body other than its actual source. - Where does it cause it? The left shoulder and arm
Nitroglycerin:
- What does it do?
- What can it treat?
- What does it do? A potent vasodilator Like NO - What can it treat? Myocardial ischemia (and other conditions)
Myocardial Infarct:
- Define myocardial infarct:
- Define infarct:
- Define myocardial infarct:
heart attack.
A failure to supply blood to a region of the myocardium - Define infarct:
A small local area of tissue death from failure to supply blood
Why is an infarct particularly nasty for myocardial cells?
Cells of the myocardium are designed to run aerobically. If this fails, then the cells can only run a few minutes on anaerobically and then cell death will occur.
What cells which lie within the area of myocardium infarction?
They will die fairly quickly.
The scar tissue will not be contractile.
In what way can a heart attack be a positive feedback loop.
- Explain “time is muscle”:
Initial death from obstruction of coronary arteries.
The death causes a region which can no longer contract.
This can cause increased ischemia and regions of infarction.
Which can cause more death and the loop continues.
- Explain “time is muscle”:
Meaning the longer before tPA or other factors kick in, the longer the positive feedback loop above will be able to kill more ischemic tissue
Reperfusion injury:
- Cause:
- Effect:
- Cause:
DAMAGE CAUSED BY OXYGEN RETURN, RE- PERFUSION OF TISSUE
Apoptosis due to accumulation of Ca2+ and production of superoxide free radicals (ROS, reactive oxygen species) by mitochondria. - Effect:
cells with these conditions will commit apoptosis
Possible medical reperfusion injury treatments:
- Stem cell therapies:
- Stimulated myocardial cell division:
- Stem cell therapies: from bone marrow (so far no luck) - Stimulated myocardial cell division: (It works in rodent hearts)
What is the number one cause of death in the western world?
Why?
Myocardial infarction
Are diets are garbage, we do not have exercised focus lifestyles, and we live lives of elevated stress (hypertension)
myocardial ischemia is normally accompanied by what?
myocardial infarction is normally accompanied by what?
Depression of the S-T segment.
Elevation of the S-T segment.
Enzymes or components of cell used to measure myocardial infarction:
- Which two are the most sensitive?
- Which is the longest lasting indicator?
Troponin I and T Creatine phosphokinase Lactate Dehydrogenase (high levels in heart because it is used in aerobic respiration) - Which two are the most sensitive? Troponin I and T -Which is the longest lasting indicator? Lactate Dehydrogenase
Two Arrhythmias:
- Bradycardia:
- Tachycardia:
- What is considered the most severe arrhythmia?
- Bradycardia:
< 60 bpm - Tachycardia:
> 100 bpm - What is considered the most severe arrhythmia?
Ventricular tachy cardia (can become ventricular fibrillation)
Atrial Flutter:
- Commonly digresses into:
An irregular circular electrical current in the atria.
- Commonly digresses into:
Atrial Fibrillation. (which will not kill you instantly, as the atria isn’t the most needed)
20 - 25% percent of strokes are estimated to be caused in thrombi from where?
- Caused by what?
- How is it treated?
Atria - Caused by what? Atrial fibrillation - How is it treated? Antithrombic drugs, like warfarin (Coumadin)