Pathophysiology of heart and circulation – Chapter 1
The need for a circulatory system
All living cells require:
1. Metabolic substrates (e.g. oxygen, AA, glucose)
2. Mechanism to remove by products of metabolism (e.g. CO2, lactic acid)
Exchange between blood and the outside environment occurs in different organs:
lungs, GI, kidney and the skin
Blood passing through the intestine picks up glucose, AA, fatty acids and other
substances the blood then delivers these substances to the organs
The arrangement of the cardiovascular system
2 primary components + 1 other component:
1. The heart
a. Pulmonary circulation: lungs
b. Systemic circulation: full body
2. The blood vessels
3. Lymphatic system: does not contain blood but has an
important exchange function in conjunction (combinatie)
with blood vessels
Right atrium right ventricle pulmonary artery lungs pulmonary vein left
atrium left ventricle aorta large artery small artery arteriole
capillaries venule vein superior and inferior vena cava
As blood flows through organs some of the fluid leaves the
circulation and enters the tissue interstitium (fluid filtration). The
lymphatic vessels collects the excess fluid and transport it back
into the venous circulation by way of lymphatic ducts that empty
into large veins (subclavian veins)
The left and right part have an in-series relationship that requires:
1. That the output (volume of blood ejected per unit time) of each side
closely matches the output of the other side
2. That most of the major organ systems are in parallel
One exception is the liver: aorta GI hepatic portal system
liver OR aorta hepatic artery liver
Arrangement in parallel: blood flow in one organ has relatively little
influence on blood flow in another organ
Arrangement in series: blood flow changes in one vascular bed
significantly alter blood flow to the other vascular bed
The function of the heart and blood vessels
The heart
Heart receives blood from veins at a low pressure (near 0 mm Hg) and then eject the
blood into the arterial blood vessels with a high pressure (systolic pressure) (100-140
mm Hg)
The need for a circulatory system
All living cells require:
1. Metabolic substrates (e.g. oxygen, AA, glucose)
2. Mechanism to remove by products of metabolism (e.g. CO2, lactic acid)
Exchange between blood and the outside environment occurs in different organs:
lungs, GI, kidney and the skin
Blood passing through the intestine picks up glucose, AA, fatty acids and other
substances the blood then delivers these substances to the organs
The arrangement of the cardiovascular system
2 primary components + 1 other component:
1. The heart
a. Pulmonary circulation: lungs
b. Systemic circulation: full body
2. The blood vessels
3. Lymphatic system: does not contain blood but has an
important exchange function in conjunction (combinatie)
with blood vessels
Right atrium right ventricle pulmonary artery lungs pulmonary vein left
atrium left ventricle aorta large artery small artery arteriole
capillaries venule vein superior and inferior vena cava
As blood flows through organs some of the fluid leaves the
circulation and enters the tissue interstitium (fluid filtration). The
lymphatic vessels collects the excess fluid and transport it back
into the venous circulation by way of lymphatic ducts that empty
into large veins (subclavian veins)
The left and right part have an in-series relationship that requires:
1. That the output (volume of blood ejected per unit time) of each side
closely matches the output of the other side
2. That most of the major organ systems are in parallel
One exception is the liver: aorta GI hepatic portal system
liver OR aorta hepatic artery liver
Arrangement in parallel: blood flow in one organ has relatively little
influence on blood flow in another organ
Arrangement in series: blood flow changes in one vascular bed
significantly alter blood flow to the other vascular bed
The function of the heart and blood vessels
The heart
Heart receives blood from veins at a low pressure (near 0 mm Hg) and then eject the
blood into the arterial blood vessels with a high pressure (systolic pressure) (100-140
mm Hg)
