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

Explain alterations occurring in fruits and vegetables, Alterations occurri...

Alterations occurring in fruits and vegetables You may already be aware that fruits and vegetables vary greatly in their chemical composition. Though, some generalizations are

How is heart contraction triggered, Q. How is heart contraction triggered? ...

Q. How is heart contraction triggered? Heart contraction is independent from neuronal stimulus although it can be modulated by the autonomous nervous system in the heart there

Do sponges have circulatory system, Q. Do sponges have circulatory, nervous...

Q. Do sponges have circulatory, nervous and excretory systems? Sponges do not have a nervous system neither excretory system nor circulatory system.

Define functions of inorganic phosphorus, Define Functions of Inorganic Pho...

Define Functions of Inorganic Phosphorus? The major functions of inorganic phosphorus include: a) Structural component of bones and teeth: Phosphorus is a part of calcium ph

Determine major aspects of the mechanism of freeze drying, Determine Major ...

Determine Major Aspects of the Mechanism of Freeze Drying? The major aspects of the mechanism of freeze drying are:  (a) The removal of vapour from the subliming ice front w

Define the effect of dietary fibre on nutrient absorption, Define the effec...

Define the effect of dietary fibre on Nutrient Absorption? Nutrient Absorption: Inclusion of fibre has been shown to retard the absorption of some nutrients. The inclusion of v

Cryobiology, Cryobiology : This is the study of life at low temperature. Cr...

Cryobiology : This is the study of life at low temperature. Cryobiology is that branch of biology which studies the effects of low temperatures on living things. Cryobiology scienc

Locomotion in annelida, Locomotion in Annelida Before we discuss the ...

Locomotion in Annelida Before we discuss the details of locomotion in annelids, we have to recapitulate the major subdivisions of the phylum Annelida. Phylum Annelida contain

Population growth curve, Increase in population size is known as population...

Increase in population size is known as population growth. It depends upon number of persons added to the population and number of persons lost from the population. Addition in pop

Circulation - initiation of cpr, Circulation: If central pulses (femor...

Circulation: If central pulses (femoral  in infants and  carotid in  children) are not  palpable, begin chest compression without losing any time.  In  young infants, encircle

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