Ischemia

Question 1

What is ischemia?

Answer 1

A condition where the blood (thus the oxygen) is restricted or reduced in a part of the body

Question 2

What is cardiac ischemia/myocardial ischemia?

Answer 2

A restriction or reduced blood flow (hence, oxygen supply) to the heart muscle.

There is no enough oxygen to combust carbon fuels to make ATP

Question 3

1. what does the heart need?

What are the 3 things we need to consider if a patient presents with a cardiac dysfunction?

Answer 3

1. WHAT SUPPLIES does the heart need to work properly?
2. What could INTERRUPT those supplies?
3. How can we determine if the patient has suffered ischemic attack?

Question 4

What does a blockage of the blood vessels supplying blood to the heart result to?

Answer 4

A sudden severe blockage of the heart can present with serious abnormal heart rhythms/angina pain, and can lead to HEART ATTACK

Question 5

How many grams of glucose, tryglycerides and free fatty acids are circulating fuel in the body?

Answer 5

Glucose - 20g (80kcal)
Triglycerides - 3g (30kcal)
Free fatty acids - 0.3g (3kcal)

Question 6

Think of what energy supply we mainly use for aerobic respiration

What energy source is the main supplier of energy during/immediately after eating?

Answer 6

Glucose - aerobic respiration

Question 7

When you wait for your next meal

What energy source is the main supplier of energy between meals?

Answer 7

fatty acids - beta oxidation

Question 8

Think about what causes fruity smell on the mouth

What energy source is the main supplier of energy during starvation?

Answer 8

Ketone bodies and fatty acids

Question 9

What happens to pyruvate during anaerobic respiration?

Answer 9

Pyruvate can be reduced into lactase which produces NAD+ by LACTATE DEHYDROGENASE

Pyruvate + NADH + —-> Lactate + NAD+

Question 10

What parts of the body usually use lactate?

Answer 10

The liver - to make glucose
Muscle - to provide pyruvate for the Citric Acid cycle

Question 11

What is the primary effect of ischemia?

Answer 11

Reduced production of ATP
Reduced pH (due to lactic acid production)
Calcum accumulation
Potassium efflux
Increased permeability (myocyte swelling)
Free radicals

(Lactic acid, ATP, Calcium, Potassium)

Question 12

What occasions result in reduced oxygen availability?

Answer 12

Physical exercise, Severe lung disease, High altitude, Drowning, Severe anaemia, Carbon Monoxide poisoning (replaces oxygen in red blood cells), Cyanide poisoning

Question 13

Vitamins

What antioxidants mop up radicals?

Answer 13

Vitamin A, C and E
Enzymes - Catalase