PNB CIRCULATION 1 EXAM QUESTIONS
WITH 100% CORRECT ANSWERS
What did Galen propose about the vascular system? - Answer- It was open-ended (air
and blood in arteries; pores in heart).
What is the primary purpose of the coronary circulation? - Answer- To supply blood to
the heart muscle itself.
What percentage of the oxygen content in the coronary arteries does the coronary
circulation consume? - Answer- 75%.
From where do the left and right coronary arteries branch? - Answer- The aortic root.
What does the Right Coronary Artery (RCA) primarily supply? - Answer- The right
atrium and portions of the left ventricle.
What is the pressure in the aorta when the heart contracts known as? - Answer-
Systolic pressure.
What is the typical value for systolic pressure in the aorta? - Answer- Approximately 120
mmHg.
What is the pressure in the aorta between heartbeats during ventricular relaxation
known as? - Answer- Diastolic pressure.
What is the typical value for diastolic pressure in the aorta? - Answer- Approximately 80
mmHg.
Which vessels act as the 'pressure reservoirs' of the circulatory system? - Answer-
Arteries.
How do elastic arteries smooth out the surge in blood pressure during systole? -
Answer- They store kinetic energy in their walls by expanding.
What are the three mechanisms that mediate venous return in the absence of a pulse
pressure? - Answer- Skeletal muscle pump, respiratory pump, and sympathetic venous
innervation.
, What happens to intra-thoracic pressure during inhalation? - Answer- It decreases
(creating negative pressure).
What happens to intra-abdominal pressure during inhalation? - Answer- It increases.
How does sympathetic venous innervation facilitate venous return? - Answer- It causes
venous constriction, which increases the volume of blood returning to the heart.
What is the relationship between vessel radius (r) and resistance (R) according to
Poiseuille's law? - Answer- R ∝ 1/r^4.
Blood flow is directly proportional to the pressure gradient (ΔP) and inversely
proportional to what? - Answer- Resistance (R).
Where does the pulmonary circulation loop end? - Answer- Left ventricle.
Which segment of the systemic circulation supplies the head, neck, and arms? -
Answer- The aortic arch.
Which segment of the systemic circulation supplies the abdominal organs and legs? -
Answer- The abdominal aorta.
Which type of blood vessel has the highest proportion of elastic tissue? - Answer-
Arteries.
What are abnormal heart sounds known as murmurs primarily caused by? - Answer-
Valve narrowing or insufficiency (backflow).
What is the clinical term for the narrowing of a heart valve that produces a murmur? -
Answer- Stenosis.
During which phase of the cardiac cycle is the abnormal heart sound S3 produced? -
Answer- Ventricular filling.
What event produces the abnormal heart sound S4? - Answer- Atrial contraction.
What pathology typically causes abnormal heart sounds described as 'clicks'? - Answer-
Mitral valve prolapse.
During mitral valve prolapse, the valve leaflets bulge back into which heart chamber? -
Answer- The left atrium.
When does the heart sound S1 occur in the cardiac cycle? - Answer- At the beginning
of ventricular systole.
WITH 100% CORRECT ANSWERS
What did Galen propose about the vascular system? - Answer- It was open-ended (air
and blood in arteries; pores in heart).
What is the primary purpose of the coronary circulation? - Answer- To supply blood to
the heart muscle itself.
What percentage of the oxygen content in the coronary arteries does the coronary
circulation consume? - Answer- 75%.
From where do the left and right coronary arteries branch? - Answer- The aortic root.
What does the Right Coronary Artery (RCA) primarily supply? - Answer- The right
atrium and portions of the left ventricle.
What is the pressure in the aorta when the heart contracts known as? - Answer-
Systolic pressure.
What is the typical value for systolic pressure in the aorta? - Answer- Approximately 120
mmHg.
What is the pressure in the aorta between heartbeats during ventricular relaxation
known as? - Answer- Diastolic pressure.
What is the typical value for diastolic pressure in the aorta? - Answer- Approximately 80
mmHg.
Which vessels act as the 'pressure reservoirs' of the circulatory system? - Answer-
Arteries.
How do elastic arteries smooth out the surge in blood pressure during systole? -
Answer- They store kinetic energy in their walls by expanding.
What are the three mechanisms that mediate venous return in the absence of a pulse
pressure? - Answer- Skeletal muscle pump, respiratory pump, and sympathetic venous
innervation.
, What happens to intra-thoracic pressure during inhalation? - Answer- It decreases
(creating negative pressure).
What happens to intra-abdominal pressure during inhalation? - Answer- It increases.
How does sympathetic venous innervation facilitate venous return? - Answer- It causes
venous constriction, which increases the volume of blood returning to the heart.
What is the relationship between vessel radius (r) and resistance (R) according to
Poiseuille's law? - Answer- R ∝ 1/r^4.
Blood flow is directly proportional to the pressure gradient (ΔP) and inversely
proportional to what? - Answer- Resistance (R).
Where does the pulmonary circulation loop end? - Answer- Left ventricle.
Which segment of the systemic circulation supplies the head, neck, and arms? -
Answer- The aortic arch.
Which segment of the systemic circulation supplies the abdominal organs and legs? -
Answer- The abdominal aorta.
Which type of blood vessel has the highest proportion of elastic tissue? - Answer-
Arteries.
What are abnormal heart sounds known as murmurs primarily caused by? - Answer-
Valve narrowing or insufficiency (backflow).
What is the clinical term for the narrowing of a heart valve that produces a murmur? -
Answer- Stenosis.
During which phase of the cardiac cycle is the abnormal heart sound S3 produced? -
Answer- Ventricular filling.
What event produces the abnormal heart sound S4? - Answer- Atrial contraction.
What pathology typically causes abnormal heart sounds described as 'clicks'? - Answer-
Mitral valve prolapse.
During mitral valve prolapse, the valve leaflets bulge back into which heart chamber? -
Answer- The left atrium.
When does the heart sound S1 occur in the cardiac cycle? - Answer- At the beginning
of ventricular systole.
