BIOL 221 Lecture Notes - Lecture 2: Cardiac Output, Stroke Volume, Horse Length

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peachbeetle258

11 Feb 2020

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Volume of blood ejected from each ventricle per minute. Cardiac output is the volume of blood ejected from each ventricle during each minute. It averages around 5 liters per minute at rest. Cardiac output is calculated by multiplying the stroke volume in milliliters per beat by the heart rate in beats per minute. The stroke volume is the volume of blood ejected with each ventricular contraction. Cardiac reserve is the difference between a person"s resting cardiac output and maximum cardiac output. It is affected by cardiac health and training. Stroke volume is the difference between what is in the ventricle just before it contracts at the end of relaxation (end-diastolic volume) and the volume in the ventricle immediately after the heart finishes contracting (end-systolic volume). The average end-diastolic volume is 120 ml. Edv is related to venous return and filling time. Esv averages 50 ml and related to the ease with which blood is ejected.

Related Questions

Rest activity

min volume 19700ml air/min 43400 ml air /min

breathing rate 13breat/min 21

heartrate 72beats/min 112 beats/min

blood pressure 118/70 158/88

% O2 inhaled air 20.94% (.)2094ml O2/ml air) same

% O2 exhaled air 18.94% (.1894 ml O2/ml air) same

a) claculate Tidal volume [ml air/breath]
b) calculate Oxygen consumption (VO2) [ ml O2 consumed/min] -
c) calculate Oxygen content of arterial blood (CO2a) [ml O2/mlblood] -
d) calculate Oxygen content of venous blood (CO2v) [ml O2/ml blood]-
You need to know that there is 13.3 g hemoglobin/100 ml blood, and1.3
ml O2 binds to each gram of hemoglobin. Assume arterial blood is100%
saturated with oxygen, whereas mixed venous blood is 60%saturated
when the subject is resting.
e) caluclate Cardiac Output (CO) [ ml blood/min ] -
f) caulculate Stroke Volume (SV) [ ml blood/beat] -

g) Tidal volume [ml air/breath]
h) Oxygen consumption (VO2) [ ml O2 consumed/min]
i) Stroke Volume (SV) [ ml blood/beat]
Assume change in stroke volume is the same as the change inpulse
pressure when going from rest to exercise - s
j) Cardiac Output (CO) [ ml blood/min ] -
k) Oxygen content of arterial blood (CO2a) [ml O2/ml blood] = sameas when resting
l) Oxygen content of venous blood (CO2v) [ml O2/ml blood] -

Now answer these questions:

1. By what multiplication factor (e.g. 2 times, 3 times, etc.)did oxygen consumption
increase over resting when the person exercised?
2. a. Did minute volume increase by the same factor that oxygenconsumption
increased? If not, what made up the difference?
b. Did cardiac output increase by the same factor that oxygenconsumption
increased? If not, what made up the difference?
3. What was most responsible for the change in minute volume? i.e.compare the
factorial change in breathing rate with that of tidal volume.
4. What was most responsible for the change in cardiac output? i.e.compare the
factorial change in heart rate with that of stroke volume.
5. Calculate total peripheral resistance during rest and exercise(see pg 21). What
physiological changes led to the change in peripheral resistance?In what part of the
body did they occur, and why is this adaptive?

ivorymuskrat878

Potentially useful information: one mL = one cm³ = 10^-6 m³, one mmHg = 133.3 Pa (N/m²). SV = EDV â ESV. CO = HR X SV. Ejection Fraction = SV/EDV

Hints: calculate heart rate for each condition. Remember to calculate work for the entire volume of blood that is pressurized i.e., end diastolic volume (EDV). Therefore you will need to use the data provided to calculate the EDV to answer this question.

The work done by the heart is Pressure-Volume work. While both ventricles are doing work, in this problem you will just calculate the work done by the left (high pressure) ventricle. In lecture you saw that if both pressure and volume are expressed in SI units, their product is NÂ·m (work!) In this assignment you will calculate the work done by the left ventricle of the heart each minute to support a cardiac output of 5L/min.

1.)In a healthy person make the following assumptions: Stroke volume is 70mL and the Ejection Fraction is 58% (these are normal values). If systolic pressure is 120 mmHg, what is the work that the heart must perform each minute to produce a cardiac output of 5 L/min?

2.) Individuals with hypertension (high blood pressure) have a much greater resistance in their blood vessels and thus their heart not only has to produce greater pressure, it will have a much greater volume left following contractions (end systolic volume, ESV) Calculate the work the heart (for the identical cardiac output of 5L/min) in an individual with stage one hypertension for which these values apply: systolic blood pressure of 150 mmHg, an ejection fraction of 40% and a stroke volume of 60mL.

3.) 150mmHg is 25% greater than 120 mmHg. In this individual, how much greater is their cardiac work?

silverdinosaur935

Potentially useful information: one mL = one cm³ = 10^-6 m³, one mmHg = 133.3 Pa (N/m²). SV = EDV â ESV. CO = HR X SV. Ejection Fraction = SV/EDV

The work done by the heart is Pressure-Volume work. While both ventricles are doing work, in this problem you will just calculate the work done by the left (high pressure) ventricle. If both pressure and volume are expressed in SI units, their product is NÂ·m (work!) In this assignment you will calculate the work done by the left ventricle of the heart each minute to support a cardiac output of 5L/min.

B) Individuals with hypertension (high blood pressure) have a much greater resistance in their blood vessels and thus their heart not only has to produce greater pressure, it will have a much greater volume left following contractions (end systolic volume, ESV) Calculate the work the heart (for the identical cardiac output of 5L/min) in an individual with stage one hypertension for which these values apply: systolic blood pressure of 150 mmHg, an ejection fraction of 40% and a stroke volume of 60mL.

C) In this individual, how much greater is their cardiac work (@ blood pressure 150 mmHg) than a normal individual with normal blood pressure (120 mmHg)?

Please answer these questions COMPLETELY and I'll be sure to leave a "thumbs up"! Thank you!

mauveminnow262

BIOL 221 Lecture Notes - Lecture 2: Cardiac Output, Stroke Volume, Horse Length

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