Integration of the Cardiovascular System

Question 1

How does the Baroreceptor reflex help Haemorrhage?

Answer 1

The decrease in ABP, causes the BR increase heart rate, increase ventricular contractility as well as venous and arteriolar vasoconstriction

Question 2

How does the Volume Reflex help Haemorrrhage?

Answer 2

Increase in filtration fluid into capillaries from tissue spaces as well as retention of water and sodium by the kidneys

Question 3

What happens in very severe cases of haemorrhage?

Answer 3

Without a transfusion, the baroreceptor and volume reflex cannot correct ABP. Strong reflex in vasoconstriction within the kidneys and the GIT leads to renal failure and liver failure.
Blood flow to tissues becomes extremely low

Question 4

What are the effects of exercise in a healthy person?

Answer 4

• Increase in respiration maintains PaO2 and gets rid of carbon dioxide
• Increase in heart rate and contractility
• Vasoconstriction in sphlanchnic circulation and kidney
• Vasodilation in exercising and cardiac muscle
• Functional Hyperaemia

Question 5

What are the signs and symptoms of Heart Failure?

Answer 5

• Coughing
• Tiredness
• Shortness of breath
• Pleural effusion
• Pulmonary oedema
• Ascites
• Oedema in ankles and legs

Question 6

What are the two types of HF?

Answer 6

HFpEF

• Preserved ejection fraction
• Ejection fraction >50% (EDV-ESV)
• Diastolic dysfunction - ventricular wall stiff leads to limited filling

HFrEF

• Reduced ejection fraction
• Ejection fraction <50% (EDV-ESV)
• Systolic dysfunction - dilated ventricle leads to impaired contraction

Question 7

What is decompensation? (Heart Failure)

Answer 7

When compensatory responses worsen the primary condition (HF).

• More overfilling of the heart and veins
• Increased afterload (arteriolar constriction)
• Blunting of endothelium-dependent dilatation