🏷️ LIMITED TIME OFFER: GET 20% OFF GRADE+ YEARLY SUBSCRIPTION →
Log in
Biology
5
answers
0
watching
23
views
13 Dec 2019

8. With an increase in contractility of the left ventricle, all of the following left-ventricular parameters will increase EXCEPT

A end systolic volume.

B peak systolic pressure.

C rate of pressure increase (i.e., dP/dt) during systole.

D stroke volume.

Watch
5
answers
0
watching
23
views

For unlimited access to Homework Help, a Homework+ subscription is required.

Unlock all answers

Get 1 free homework help answer.
Get unlimited access
Already have an account? Log in
Share
Get unlimited access
Already have an account? Log in
Share
Get unlimited access
Already have an account? Log in
Share
Get unlimited access
Already have an account? Log in
Share
Tod Thiel
Tod ThielLv2
17 Dec 2019
Get unlimited access
Already have an account? Log in
Share

Related textbook solutions

Molecular Cell Biology
8 Edition,
Lodish
ISBN: 9781464183393
Biology: Science for Life with Physiology
6 Edition,
Belk
ISBN: 9780134555430
Concepts of Biology
OER Edition,
Openstax
ISBN: 9781938168116
Biology
2nd Edition, 2013
Openstax
ISBN: 9781947172517
Essentials of Biology
5 Edition,
Mader
ISBN: 9781259660269

Related questions

Hi, I was wondering if you could help me with all parts of my question. Thanks!

1a)When aortic pressure is lower than left ventricular pressure:
A The aortic semilunar valve is open and the left AV valve is closed.
B The aortic semilunar valve is closed and the left AV valve is closed.
C The aortic semilunar valve is open and the left AV valve is open.
DThe aortic semilunar valve is closed and the left AV valve is open.

b)Which of the following is true?
AEnd-diastolic volume is lower than end-systolic volume.
B When the left atrium is at its maximum pressure, the left AV valve is open.
C The left ventricle is at its maximum pressure at the beginning of systole.
DWhen the left ventricle is at its maximum pressure, the left AV valve is open.
E The aorta is at its maximum pressure at the beginning of diastole.

c)Which of the following is a change that would increase MAP over an acute timescale?
A Decreased end-diastolic volume.
B Increased secretion of a hormone promoting arteriolar vasoconstriction.
C Increased activity of parasympathetic nerves to the heart.
D Decreased blood volume (e.g., due to hemorrhage).

Potentially useful information: one mL = one cm3 = 10-6 m3, one mmHg = 133.3 Pa (N/m2). SV = EDV – 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 N·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?

Potentially useful information: one mL = one cm3 = 10-6 m3, one mmHg = 133.3 Pa (N/m2). SV = EDV – 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. If both pressure and volume are expressed in SI units, their product is N·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!

Weekly leaderboard

Home
Homework Help 3,900,000
Biology 460,000
Start filling in the gaps now
Log in