CVS 2 - Anatomy & Imaging

Question 1

What are the 3 layers of arterial and venous blood vessels and what are within these layer?

Answer 1

1) Tunica Intima - endothelium layer
2) Tunica media - smooth muscle + elastic fibres
3) Tunica externa - connective tissue layer

Question 2

Describe the route that blood takes from returning to the heart from capillary beds and back out into the arterial circulation

Answer 2

• From the capillary bed, into the venous system, into the right atrium
• From the right atrium into the right ventricle and out to the lungs via the pulmonary artery
• Blood now oxygenated, to the left atrium via the pulmonary vein
• Left atrium to left ventricle, out the aorta into the arterial circulation, and distributed to capillary beds

Question 3

How is cardiac output calculated and what is the normal value for a 70Kg male under resting conditions?
What are the normal values for the constituents of CO?
How, and to what value does CO increase during exercise?

Answer 3

• CO = HR x SV. 5L/min (4-6L/min range)
• HR = 60-90bpm. SV = 55-83ml/beat
• CO increases to 20-35L/min depending on conditioning
• HR increases to 150-200bpm, SV upto 200ml/beat

Question 4

What are the 3 layers of tissue in the wall of the heart?

What are they comprised of?

Answer 4

1) Epicardium (outer layer) - serous membrane with a smooth outer surface
2) Myocardium (middle layer) - composed of cardiac muscle cells responsibly for contractility of the heart
3) Endocardium (inner layer) - smooth inner surface

Question 5

Where are the pectinate muscles + trabeculae carnae found?

Answer 5

Pectinate muscles = muscular ridges in auricles and right atrial wall

Trabeculae carnae = muscular ridges and columns on inside walls of ventricles

Question 6

What is the pericardium?

Answer 6

A double-walled sac surrounding the heart and the roots of its great vessels - split into the visceral and parietal layers.

Question 7

What are the 4 valves of the heart and where are they located?

Answer 7

• 2 x AV valves (tricuspid and mitral). Tricuspid is between the right atrium and ventricle, and mitral is between the left atrium and left ventricle
• Aortic valve - between left ventricle and aorta
• Pulmonary valve - between right ventricle and pulmonary artery

Question 8

What are the main coronary arteries and which one quickly bifurcates?

Answer 8

• The right coronary artery (supplies blood to right side of heart)
• The left main coronary artery (supplies blood to left side of heart) - bifurcates into the 1) left anterior descending descending artery (supplies blood to front and left side of heart) and 2) circumflex artery (supplies blood to outer-side and back of heart)