Cardiac output and its determination, Biology

Assignment Help:

The cardiac output is the volume of blood pumped from the heart every minute. It is obtained by the volume pumped with each beat (stroke volume) multiplied by the heart rate. The cardiac output increases during exercise and falls in the common type of heart failure. The stroke volume depends in part on the amount of blood in the ventricule at the end of diastole. This determines the degree of stretch of the myocardial fibre. The greater the stretch (within limits) the stronger the force of contraction and the greater the stroke volume (Starlings law of the heart).

Control of the heart rate depends on the ratio of the sympathetic (increases) and parasympathetic (decreases) impulses to the sino atrial node which  is the cardiac pacemaker. Receptors sensitive to pressure are located in the carotid sinus and the wall of the arch of the aorta.When the carotid sinus detects a sudden  rise in arterial pressure, impulses pass from the carotid baroreceptors to the cardiac control centre in the medulla and impulses sent through the parasympathetic system reduce the heart rate. Similar effects result from  the aortic baroreceptors as well. If the blood pressure drops the heart rate is reflexly increased. Various other reflexes from anger, fear, pain, temperature, etc. also increase the heart rate.


Related Discussions:- Cardiac output and its determination

What are energy allowance, Energy Allowance: Energy Allowance: The  p...

Energy Allowance: Energy Allowance: The  patient's requirement for  energy  varies with the physical activity and physiological condition. For instance, consider a person con

Define glycogenolysis, Define Glycogenolysis Glycogenolysis : degrad...

Define Glycogenolysis Glycogenolysis : degradation of glycogen.

Explain fluconazole, Fluconazole Fluconazole is active against most  Ca...

Fluconazole Fluconazole is active against most  Candida species other than C. krusei, which is intrinsically resistant, and many strains of C. glabrata, which are increasingly

Effect of temperature, Effect of Temperature Certain plants such as th...

Effect of Temperature Certain plants such as the winter rye (Secale cereale) and the biennial strain of henbane (Hyoscyamus Niger) require exposure to low temperature conditio

High energy fixation - nitrogen fixation, High energy fixation - Nitrogen F...

High energy fixation - Nitrogen Fixation Through cosmic radiations, lightning, volcanic activity and meteorite trails which provide the high energy needed to combine atmospher

What is atrial switch operation and rastelli in heart diease, What is Atria...

What is Atrial Switch operation and Rastelli in Heart dieases? Atrial Switch Operation: (Senning or Mustard procedures) By means of a baffle the systemic venous blood could b

Explain the queens college step test, Explain the Queens College Step Test?...

Explain the Queens College Step Test? This test can be administered to large groups or those who are incapable of doing a test up till exhaustion. For this test, a bench (41 c

Type of skull, what type of skull does amphibians possess in general?

what type of skull does amphibians possess in general?

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd