Cardiac anatomy

Question 1

What are the four chambers of the heart?

Answer 1

Left atrium, left ventricle, right atrium, right ventricle

Question 2

What are the great vessels?

Answer 2

• Into left atrium, there are the right and pulmonary veins (2 each) that bring oxygenated blood from respective lung to the heart
• Out of the left ventricle is the aorta
• Into the right atrium is the superior vena cava (brings deoxy blood from top organs) and the inferior vena cava (brings deoxy blood from bottom of the body)
• Out of the right ventricle are the right and left pulmonary arteries from the pulmonary trunk that bring deoxy blood to lungs to be oxygenated

Question 3

What are the boundaries of the atria and ventricles?

Answer 3

• There is an interatrial septum (separates blood of left and right atria)
• The inter-ventricular septum (thick and separates blood from left and right ventricles)
• The left ventricular free wall, very thick, pumps to whole body
• The right ventricular free wall, thinner, pumps just to lungs, smaller pressure is generated, DUH

Question 4

What are the different cardiac valves?

Answer 4

• Two atrioventricular valves (tricuspid/right and mitral or bicuspid/left) when the valves open, blood flows from the atrium to the ventricle and when they close, blood cannot flow backwards from the ventricle to the atrium
• There are also the vessel valves,the semilunar valves (pulmonary or pulmonic valve/right and the aortic valve/left) when the valves open, blood flows from the ventricle to the vessel and when they close, blood cannot flow backwards from the vessel into the ventricle

Question 5

Where in the heart are the valves?

Answer 5

• At the limits of the chambers and between the chambers and vessels HOWEVER specifically, they are on the fibrous ring (made up of connective tissue) which sits right between atrial muscle and ventricular muscle and acts as an electrical insulator (and where the valves sit)

Question 6

What are the individual parts of the pulmonary valve called?

Answer 6

They are leaflets/cusps which open and close

Question 7

What are chordae tendinae and papillary muscles?

Answer 7

Chordae tendinae are made up of fibrous tissue which is connective tissue, does not actively contract, one side is connected to the valve and the other side is connected to the papillary muscle
Papillary muscles are outgrowths upwards of cardiac muscle

Question 8

What is the role of chordae tendinae and papillary muscles?

Answer 8

When the ventricle contracts, the papillary muscles also contract and shorten pulling on the chordae tendinae, keeping the atrioventricular valves closed preventing backwards flow.

Question 9

What happens if the papillary muscle ruptures?

Answer 9

This will lead to mitral regurgitation and will require a mitral valve replacement to save the patient.

Question 10

What is the endocardium?

Answer 10

A thin layer of cells on the inside surface of the heart which is also found on the inside of each vessel. In the heart, it is the endocardium made up of endothelial cells.

Question 11

What is the pericardium? What is the pericardial fluid?

Answer 11

Consists of three layers: two stuck together on the outside and another one that is separated by the pericardial fluid in the pericardial space. This fluid is there because when the heart contracts it moves within the pericardial sack and the fluid serves as a form of lubrication. The pericardial sack is a very tough sack and this prevents the heart from overextending and protects it from the outside world.

Question 12

What is the circulation of the blood?

Answer 12

Left atrium, left AV valve, left ventricule, aortic valve, aorta, arteries, arterioles, capillaries, venules, veins, venae cavae, right atrium, right av valve, right ventricle, pulmonary valve, pulmonary trunk, pulmonary arteries, pulmonary arterioles, capillaries of lungs, pulmonary venules, pulmonary veins and we’re back at the left atrium