BIOS255 WEEK3 EXAM 1
Question 41: The primary function of the coronary sinus is to:
Answers:
• A. regulate blood pressure in the heart
• B. initiate the heart rate and contraction of myocardium
• C. transport oxygen-rich blood to the myocardium
• D. drain deoxygenated blood from the myocardium
The correct answer is D. drain deoxygenated blood from the myocardium.
,Explanation
The coronary sinus is a large vein that collects deoxygenated (oxygen-poor) blood from the
veins of the heart muscle (myocardium) and empties it into the right atrium of the heart.
Options A and B describe functions primarily managed by the heart's electrical
conduction system (like the SA node) and the autonomic nervous system.
Option C describes the function of the coronary arteries.
Question 9:
Use the following values to calculate the Mean Arterial Pressure (MAP) of a client. You must
show your work and provide units. You may not need all of the values to calculate your answer.
Heart rate: 84 beats/min. Systolic pressure: 110 mL. End diastolic volume: 110 mL. End
systolic volume: 65 mL. (4 pts)
Analysis and Answer
Missing Information: The calculation for Mean Arterial Pressure (MAP) requires the Diastolic
,Blood Pressure (DBP), which is not provided in the list of values. The prompt lists "Systolic
pressure: 110 mL," which contains a typo (it should be in mmHg), but the critical piece of data,
Diastolic Pressure, is missing.
Assuming this is a flawed question where only the Systolic Pressure (SBP) is given as 110
mmHg and the DBP is unstated, the MAP cannot be calculated.
However, the other values can be used to calculate Cardiac Output (CO):
1. Calculate Stroke Volume (SV):
SV=End Diastolic Volume (EDV)−End Systolic Volume (ESV)
SV=110 mL−65 mL=45 mL
2. Calculate Cardiac Output (CO):
CO=SV×Heart Rate (HR)
CO=45 mL/beat×84 beats/min=3,780 mL/min
CO=3.78 L/min
If an estimate for MAP is required and a typical DBP for a healthy client with an SBP of 110 is
assumed (e.g., 70 mmHg), the calculation would be:
MAP=3(2×70)+110=3140+110=3250≈83.3 mmHg
, The partial pressure of oxygen in arterial blood is approximately ______ mmHg.
Answer Choices:
• A. 45
• B. 50
• C. 100
• D. 40
• E. 70
The Correct Answer:
• C. 100
Explanation: In a healthy individual, the partial pressure of oxygen (PO2) in systemic arterial
blood leaving the lungs is normally close to 100 mmHg. A value of 40 mmHg would typically
represent the PO2 in systemic venous blood.
Question 41: The primary function of the coronary sinus is to:
Answers:
• A. regulate blood pressure in the heart
• B. initiate the heart rate and contraction of myocardium
• C. transport oxygen-rich blood to the myocardium
• D. drain deoxygenated blood from the myocardium
The correct answer is D. drain deoxygenated blood from the myocardium.
,Explanation
The coronary sinus is a large vein that collects deoxygenated (oxygen-poor) blood from the
veins of the heart muscle (myocardium) and empties it into the right atrium of the heart.
Options A and B describe functions primarily managed by the heart's electrical
conduction system (like the SA node) and the autonomic nervous system.
Option C describes the function of the coronary arteries.
Question 9:
Use the following values to calculate the Mean Arterial Pressure (MAP) of a client. You must
show your work and provide units. You may not need all of the values to calculate your answer.
Heart rate: 84 beats/min. Systolic pressure: 110 mL. End diastolic volume: 110 mL. End
systolic volume: 65 mL. (4 pts)
Analysis and Answer
Missing Information: The calculation for Mean Arterial Pressure (MAP) requires the Diastolic
,Blood Pressure (DBP), which is not provided in the list of values. The prompt lists "Systolic
pressure: 110 mL," which contains a typo (it should be in mmHg), but the critical piece of data,
Diastolic Pressure, is missing.
Assuming this is a flawed question where only the Systolic Pressure (SBP) is given as 110
mmHg and the DBP is unstated, the MAP cannot be calculated.
However, the other values can be used to calculate Cardiac Output (CO):
1. Calculate Stroke Volume (SV):
SV=End Diastolic Volume (EDV)−End Systolic Volume (ESV)
SV=110 mL−65 mL=45 mL
2. Calculate Cardiac Output (CO):
CO=SV×Heart Rate (HR)
CO=45 mL/beat×84 beats/min=3,780 mL/min
CO=3.78 L/min
If an estimate for MAP is required and a typical DBP for a healthy client with an SBP of 110 is
assumed (e.g., 70 mmHg), the calculation would be:
MAP=3(2×70)+110=3140+110=3250≈83.3 mmHg
, The partial pressure of oxygen in arterial blood is approximately ______ mmHg.
Answer Choices:
• A. 45
• B. 50
• C. 100
• D. 40
• E. 70
The Correct Answer:
• C. 100
Explanation: In a healthy individual, the partial pressure of oxygen (PO2) in systemic arterial
blood leaving the lungs is normally close to 100 mmHg. A value of 40 mmHg would typically
represent the PO2 in systemic venous blood.
