Cardiac output - circulation, Biology

Assignment Help:

Cardiac Output - Circulation

The cardiac output can be determined in a number of ways. The most common method is the Fick's principle. A. Fick a German physiologist in 1870 described a simple method of calculating cardiac output from measurement of oxygen consumption (or carbon dioxide production) and the difference between oxygen (or carbon dioxide) contents of blood entering and leaving the heart.

1961_Cardiac Output - Circulation 1.png

The volume of blood ejected by each beat of the heart is the stroke volume. The mean stroke volume is determined by dividing cardiac output by heart rate. In other words, cardiac output can be calculated if we know the values of heart rate and stroke volume. Therefore, cardiac output can be increased by increasing either the heart frequency or the stroke volume or both. However, in mammals there may be little change in stroke volume if cardiac output is to be altered, major adjustments are made in the heart rate. The distribution of blood to the various organs of the human body is given in Table You can see from the Table that kidneys, liver, heart and brain make up only 5% of the total body weight but receive more than half of the total cardiac output. Stroke volume can also be defined as the difference in volume of blood before and after contraction. Two factors influence stroke volume, one is the hormone adrenaline (epinephrine) which increases contractions thus forcing a larger volume of - blood out of the ventricles in a single stroke. The other is the amount of blood present in the ventricles before contraction.

1444_Cardiac Output - Circulation 2.png

If the returning venous blood to the heart is increased, then ventricles will be filled with more blood and following contraction more blood will be ejected out. This relationship between cardiac output and increased venous volume was discovered by the English physiologist Ernest H. Starling. This relationship will be further discussed when we talk of blood flow during exercise.


Related Discussions:- Cardiac output - circulation

Precautions to prevent from hiv , Precautions to prevent from HIV  To a...

Precautions to prevent from HIV  To avoid HIV infection one should practice safe sex (use of condoms). Besides a few simple precautions are given for protection against HIV inf

Taxonomy, A In taxonomy, what is a "KEY" ? List the different types of key...

A In taxonomy, what is a "KEY" ? List the different types of keys. How are they prepared and what are they used for ?sk question #Minimum 100 words accepted#

Genetic drift, It is generally believed that genetic drift occurs as a resu...

It is generally believed that genetic drift occurs as a result of sampling error. As we said earlier it occurs in small populations such as peripheral isolates. We may demonstrate

# FUNGAL NUTRITION, Write on spoilage of food products by fungi,nutrition,c...

Write on spoilage of food products by fungi,nutrition,condition for growth,consequencies and prevention.

Explain delavirdine, Explain Delavirdine Delavirdine (DLV, Rescriptor)...

Explain Delavirdine Delavirdine (DLV, Rescriptor) - Delavirdine is the least potent NNRTI. A study comparing delavirdine/zidovudine/didanosine, delavirdine plus either zidovud

What is genetic equilibrium, What is genetic equilibrium? The Genetic e...

What is genetic equilibrium? The Genetic equilibrium is the result of the Hardy-Weinberg law, a principle that affirms that under specific conditions the frequencies of the all

Classification based on digestive fate of carbohydrates, Explain Classifica...

Explain Classification Based on Digestive Fate of Carbohydrates? The digestive fate of carbohydrates depends on their inherent chemical nature (monosaccharide composition and t

Cartilage occur in a joint and what it its function, Where does cartilage o...

Where does cartilage occur in a joint and what it its function? Cartilage might be found covering the surface of bones where they meet in a movable joint. Cartilage decreases f

Respiration, what is the bet way to asses energy production in the body of ...

what is the bet way to asses energy production in the body of an athlete?

Mating and fertilisation, Mating and Fertilisation In all animals sper...

Mating and Fertilisation In all animals sperms are motile and have to move and seek the eggs to fertilise them. For this an aqueous environment is necessary. This need of a li

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