Anatomy of the heart

Question 1

Describe the location of the heart.

Answer 1

• In the region of the thoracic cavity called the mediastinum
• Medial to the lungs
• Anteriorly to the vertebrae
• Posteriorly to the sternum 2/3 of its bulk on the left side

Question 2

State the function of the valves in the heart.

Answer 2

The pulmonary semi - lunar valve - Prevents backflow of blood from the pulmonary trunk into the right ventricle

The aortic semi-lunar valve - Prevents backflow of blood from the aorta into the left ventricle

Question 3

State what cause the S1 heart sounds

Answer 3

First set = Atrioventricular valves (AV valves)
Between the atria and ventricles.
Right side the TRICUSPID
Left side the BICUSPID (MITRAL) valve.
Open and close together. On closure = 1st HS LUB (S1)

Question 4

State what cause the S2 heart sounds

Answer 4

Second set = Semilunar valves (SL valves)
Between the left ventricle and aorta = AORTIC VALVE
Right ventricle and pulmonary trunk = PULMONARY valve
Open and close together. On closure = 2nd HS Dub (S2)

Question 5

State the major arteries which attach to the heart

Answer 5

• Aorta (ascending aorta, arch of the aorta, descending aorta)
• Pulmonary trunk (left and right pulmonary arteries)
• Coronary arteries

Question 6

State the major veins which attach to the heart.

Answer 6

• Superior and inferior venae cavae
• Pulmonary veins
• Coronary sinus

Question 7

List the three layers of the heart AND describe their function

Answer 7

• Pericardium (the inner layer)
• Protects: Fibrous pericardium tough, very dense, non flexible connective tissue
• Anchors to surrounding structures
• Stops the heart from overfilling
• Myocardium (middle layer)
• Is a cardiac muscle which pumps blood, thickest layer of the heart
• Endocardium (outer layer)
• Minimises surface friction as blood flows through the heart