Chapter 2
2.1 A matter of the heart
The heart
The right side pumps blood to your lungs. The left-hand side pumps oxygen-rich blood
to all other organs in the body. This is why the left side of your heart has a thicker wall
of cardiac muscle tissue than the right side.
Your heart has 4 areas, called chambers:
● Left atrium (upper side)
● Right atrium (upper side)
● Left ventricle (lower side)
● Right ventricle (lower side)
Your heart beats by contracting and relaxing
its cardiac muscle tissue. During a single
heartbeat, both atria contract. When they
relax, both ventricles contract. This repeats
itself over and over.
Four heart valves
Blood flows in only 1 direction:
atria → ventricles → lungs and other organs
There is a 1-way valve between each atrium and each ventricle, these only open in 1
direction. The valve between the right atrium and the right ventricle is the tricuspid
valve (blue side). The valve between the left atrium and the left ventricle is called the
bicuspid valve (red side). The valve between the right ventricle and the luminary artery
is called the pulmonary valve. The valve between the left ventricle and the aorta is called
the aortic valve.
The left side of the heart is rich in oxygen (red side). The right side contains
oxygen-poor blood (blue side). A wall between the heart's left and right parts, the
septum separates these 2 types of blood. If these types mix your cells could not receive
the oxygen they need.
, 2.2 What goes around comes around
The pulmonary circulation
The blood flow from the heart to the lungs and back is called the pulmonary circulation.
It connects the heart with the lungs through blood vessels which are called veins and
arteries.
Veins → heart
Arteries ← heart
Your blood becomes oxygenated in the
lungs. Your blood then transports the
oxygen along your 2 pulmonary veins
towards the heart, where it enters the left
atrium. When the oxygen is delivered to the
cells of your body, your blood becomes
deoxygenated. This blood also contains a lot of waste such as CO2 made by your cells.
Your heart pumps this blood towards your 2 pulmonary arteries. Now the CO2 can
leave your body in the air you breathe out.
The systemic circulation
Oxygenated blood is transported to all of your other cells, tissues and organs utilising
systemic circulation.
Oxygenated blood is pumped away from the heart to the cells through arteries. The
main artery that transports blood directly from the heart is the aorta.
Deoxygenated blood is transported from the cells towards the heart through veins. The
main ones are called the superior vena cava and the inferior vena cava. both of these
collect blood from smaller veins such as the liver vein and renal vein.
The coronary circulation
The blood flow to and from the cardiac tissues is called the coronary circulation (in the
heart). A small portion of oxygenated blood from the aorta flows into the coronary
arteries to deliver oxygen to the cardiac tissues.
2.1 A matter of the heart
The heart
The right side pumps blood to your lungs. The left-hand side pumps oxygen-rich blood
to all other organs in the body. This is why the left side of your heart has a thicker wall
of cardiac muscle tissue than the right side.
Your heart has 4 areas, called chambers:
● Left atrium (upper side)
● Right atrium (upper side)
● Left ventricle (lower side)
● Right ventricle (lower side)
Your heart beats by contracting and relaxing
its cardiac muscle tissue. During a single
heartbeat, both atria contract. When they
relax, both ventricles contract. This repeats
itself over and over.
Four heart valves
Blood flows in only 1 direction:
atria → ventricles → lungs and other organs
There is a 1-way valve between each atrium and each ventricle, these only open in 1
direction. The valve between the right atrium and the right ventricle is the tricuspid
valve (blue side). The valve between the left atrium and the left ventricle is called the
bicuspid valve (red side). The valve between the right ventricle and the luminary artery
is called the pulmonary valve. The valve between the left ventricle and the aorta is called
the aortic valve.
The left side of the heart is rich in oxygen (red side). The right side contains
oxygen-poor blood (blue side). A wall between the heart's left and right parts, the
septum separates these 2 types of blood. If these types mix your cells could not receive
the oxygen they need.
, 2.2 What goes around comes around
The pulmonary circulation
The blood flow from the heart to the lungs and back is called the pulmonary circulation.
It connects the heart with the lungs through blood vessels which are called veins and
arteries.
Veins → heart
Arteries ← heart
Your blood becomes oxygenated in the
lungs. Your blood then transports the
oxygen along your 2 pulmonary veins
towards the heart, where it enters the left
atrium. When the oxygen is delivered to the
cells of your body, your blood becomes
deoxygenated. This blood also contains a lot of waste such as CO2 made by your cells.
Your heart pumps this blood towards your 2 pulmonary arteries. Now the CO2 can
leave your body in the air you breathe out.
The systemic circulation
Oxygenated blood is transported to all of your other cells, tissues and organs utilising
systemic circulation.
Oxygenated blood is pumped away from the heart to the cells through arteries. The
main artery that transports blood directly from the heart is the aorta.
Deoxygenated blood is transported from the cells towards the heart through veins. The
main ones are called the superior vena cava and the inferior vena cava. both of these
collect blood from smaller veins such as the liver vein and renal vein.
The coronary circulation
The blood flow to and from the cardiac tissues is called the coronary circulation (in the
heart). A small portion of oxygenated blood from the aorta flows into the coronary
arteries to deliver oxygen to the cardiac tissues.
