Quiz 7

Which condition should show the highest overall mean arterial pressure (MAP) reading?

Blood pressure is affected by gravity. Since the standing position will be most affected by gravity, it should have the highest overall blood pressure as measured by MAP.

Lance Armstrong is one of the best trained endurance athletes in the world. His resting heart rate is under 30 beats per minute. His heart rate is referred to as

Bradycardia is a heart rate that is less than 60 beats per minute.

Which of the following vessels types is responsible for exchange?

Capillaries are the major sites of exchange in the cardiovascular system.

Given the following variables, calculate the cardiac output for a person who is exercising. The systolic blood pressure is 110 mmHg, the diastolic blood pressure is 80, the heart rate is 146 beats/min, the total peripheral resistance is 0.007 mmHg x min/ml, the stroke volume is 88.1 ml/beat. The cardiac output in ml/min is:

Cardiac output (Q) is calculated by the product of heart rate (HR) x stroke volume (SV). Thus, we just need to identify those and replace in the equation: Q = 146 beats/min x 88.1 ml/beat = 12,862.6 ml/min

Given a person who just had a heart attack and had a stroke volume (SV) of 30 ml/beat and an end systolic volume (ESV) of 90 ml/beat, then the ejection fraction would be 0.33.

Ejection fraction (EF) = stroke volume (SV) / end diastolic volume (EDV). It can be reported as a percentage or can appear as a decimal. If it is a percentage, you need to multiply by 100 at the end. The problem states that the stroke volume (SV) is 30 ml/beat and the end systolic volume (ESV) is 90 ml/beat. Since we need to have end diastolic volume (EDV), we can calculate it by adding SV and ESV together since EDV = SV + ESV. Thus, EDV = 30 ml/beat + 90 ml/beat = 120 ml/beat. Now we can calculate EF: EF = SV / EDV = 30 ml/beat / 120 ml/beat = 0.25. Thus, the ejection fraction (EF) is 0.25, not 0.33.

Given the following variables, what is the ejection fraction? HR=120 beats/min, ESV=30 ml, EDV=190 ml, TPR=0.005 min x mmHg/ml

Given all of the variables, we only need to use a few of them. We need to find SV and ESV since ejection fraction (EF) = stroke volume (SV) / end diastolic volume (EDV). SV = end diastolic volume (EDV) - end systolic volume (ESV). Since these are given: SV = 190 - 30 = 160 Now, just replace the numbers we have: EF = 160 / 190 = 0.842

A patient enters the hospital after a heart attack has destroyed only her sinoatrial node. Upon admission, her heart rate (bpm) is most likely

Given that the fastest intact nodal tissue becomes the pacemaker, since the SA node no longer functions, the AV node would take over. In that case, the heart rate would be around 50 as that is the inherent rate of the AV node.

Given the following data, calculate the NFP. IFHP = 0, IFOP = 5, BHP = 40, BCOP = 30. What is the NFP?

Given the following data, calculate the NFP. IFHP = 0, IFOP = 5, BHP = 40, BCOP = 30. What is the NFP? Since NFP (net filtration pressure) = (forces out) - (forces in). The forces out = BHP (blood hydrostatic pressure) + IFOP (interstitial fluid osmotic pressure). The forces in = BCOP (blood capillary osmotic pressure) + IFHP (interstitial fluid hydrostatic pressure). Thus, NFP = (BHP + IFOP) - (BCOP + IFHP) = (40 + 5) - (30 + 0) = +15

blood pressure measured at 146/76, determine if she has hypertension.

Hypertension is considered when the systolic pressure is 140 or above and/or the diastolic pressure is 90 or above. Since Annette's blood pressure reading is 146/76, she only makes the hypertension criteria in the systolic region.

Using Starlings forces in capillaries, where would you expect the blood colloid osmotic pressure (BCOP) to be the highest?

It is the venous end because normally fluid can leave the capillary, but the proteins generally do not exit. Thus, they are effectively more concentrated as you move further down the capillary towards the venous end as it loses fluid, but the proteins stay and become more concentrated. This will result in a higher value.

Given the following variables, what is the mean arterial pressure? HR=120 beats/min, ESV=30 ml, EDV=190 ml, TPR=0.005 min x mmHg/ml

MAP = HR x SV x TPR. We are given the HR and TPR, but we need to calculate the SV. SV = EDV - ESV, so: SV = 190 - 60 = 160, so: MAP = 120 x 160 x 0.005 = 96 mmHg

Given the following variables, calculate the mean arterial pressure for a person who is exercising. The systolic blood pressure is 122 mmHg, the heart rate is 161 beats/min, the total peripheral resistance is 0.006 mmHg x min/ml, the stroke volume is 93 ml/beat. The mean arterial pressure is:

Mean arterial pressure (MAP) can be calculated by a couple of different methods. You can use blood pressure readings, but we are only given the systolic blood pressure measurement, so we cannot calculate it that way. Thus we need to use this one: mean arterial pressure (MAP) = heart rate (HR) x stroke volume (SV) x total peripheral resistance (TPR) Thus, replacing the numbers into the equation: MAP = 161 beats/min x 93 ml/beat x 0.006 mmHg x min/ml = 89.8 mmHg

resting blood pressure measured as 114/76, what is the mean arterial pressure in mmHg?

Mean arterial pressure (MAP) is calculated by a variety of methods: MAP = 1/3 systolic pressure + 2/3 diastolic pressureMAP = 1/3 (114) + 2/3 (76) = 38 + 50.7 = 88.7 PP (pulse pressure) = systolic pressure - diastolic pressurePP = 114 - 76 = 38MAP = 1/3 pulse pressure (PP) + diastolic pressureMAP = 1/3 (38) + 76 = 12.7 + 76 = 88.7 So by either method, you get 88.7 mmHg.

During the ECG, which of the following best corresponds to atrial depolarization?

P = atrial depolarization QRS = atrial reploarization and ventricular depolarization T = ventricular reploarization Thus, P = atrial depolarization

resting blood pressure measured as 114/76, what is the pulse pressure (PP) in mmHg?

PP (pulse pressure) = systolic pressure - diastolic pressure PP = 114 - 76 = 38

In the human body, which of the following variables normally has the greatest effect on resistance.

Poisieulle's law quantifies the relationship between the various factors that affect resistance in the human body. Poisieulle's law states the following: Resistance (R) = 8L x n / r4 where L = length, n = viscosity, r = radius. Given that raising radius to the fourth power, small changes in radius can have large impacts on resistance and therefore, flow.

Diagnosed with polycythemia vera. What would happen to resistance with this condition?

Polycythemia vera is a condition where a person has an excessive number of red blood cells. This results in an increase in the viscosity of the fluid, so resistance to flow would go up as the blood is hicker and harder to push.

During ventricular ejection, how many total valves of the heart are open?

Since blood is being ejected out of both ventricles at this time, both the aortic semilunar valve and the pulmonic semilunar valve must be open. The artiocentricular valves are closed to prevent the backflow of blood, so there are two valves open at this point in time.

If there was a greater amount of blood in the left ventricle than normal, pressure in the left ventricle would

Since pressure in a closed chamber is proportional to volume, if any chamber of the heart (including the left ventricle) had more volume, it would exert a higher pressure. So the pressure would increase.

heart rate of 122 beats/min, what is the BEST estimate of his mean arterial pressure (MAP) given that the QT segment measured 0.25 seconds and the TQ segment measured 0.25 seconds ?

Since the QT and TQ segments are roughly equal in time it is best to use 1/2 and 1/2. The QT segment represents ventricular systole and the TQ segment represents ventricular diastole and given Joe is spending about half of his time in each, the mean arterial pressure (MAP) is best calculated as 1/2 systolic + 1/2 diastolic as it refers to the average blood pressure over time.

This septum prevents the wave of depolarization from passing directly to the ventricles from the atria.

The atrioventricular septum prevents the electrical activity from going directly from the atria to the ventricles, which helps the ventricles to contract from the bottom up, pushing blood out against less resistance.

A group looked at the blood pressure measurements for reclining, sitting and standing for two minutes. Their data followed expectations. Please indicate which one of the following trials was from the reclining position. A = 120/80, B = 110/90, C = 130/70 or D = 140/100.

The expectation would be that the reclining position would have the lowest overall blood pressure. In order to answer this question, we need to calculate the mean arterial pressure for each condition. You can either use the 1/3 systolic pressure + 2/3 diastolic pressure formula or the 1/3 pulse pressure + diastolic. So given those equations:, converting to MAP we get the following: A = 120/80, so MAP = 93.3 B = 110/90, so MAP = 96.7 C = 130/70, so MAP = 90.0 D = 140/100, so MAP = 113.3 Given condition C (130/70) has the lowest mean arterial pressure, it is the reclining position since the data followed expectations.

The area of the heart that generally receives blood from the systemic circuit is the

The right atrium receives blood from the systemic circulation.

Capillaries are considered to be the greatest site of resistance since they have the smallest total cross sectional area.

This is false as capillaries have extremely large total cross sectional diameters. It is the arterioles that have the smallest total cross sectional diameters and therefore, they are the greatest sites of resistance.

During atrial systole, the semilunar valves are open and the atrioventricular valves are closed.

This is false. During atrial systole, the atria are contracting and pushing blood into the ventricle. In order to do this, the AV valves must be open and the semilunar valves must be closed.

Generally, the cardiovascular system is made up of four parts, the heart, the vessels, the lungs and the blood.

This is false. The cardiovascular system has three major components - heart, vessels and blood.

Generally we measure pressure in units of mmHg. These units are also named in honor after the person who did a tremendous amount of research in the area. Who was this?

Torricelli was the first scientist to recognize that air had pressure, so the units of mmHg are sometimes named after him - Torr.

the difference between his right atrium and the point where his most prominent vein of the dorsal venous network on the back of his left hand collapsed to be 118 mm. What is the venous pressure in mmHg?

Venous pressure is calculated as the difference in mm between when the veins on the back of the hand collapse (the dorsal venous network) and the height of the right atrium as estimated by the anterior axillary line (top of the armpit). Then you need to divide this number by 13.6 to account for the density difference between blood and mercury to get to the units of mmHg. Thus, given the data: venous pressure = 118 mm/ 13.6 = 8.7 mmHg