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

Define meat as a rich source of protein, Define Meat as a Rich Source of Pr...

Define Meat as a Rich Source of Protein? Skeletal or striated muscles are used for food purposes. Flesh of cattle, sheep and swine comprise most of the meat contents. Edible me

Neuroglia - organisation of nervous system, Neuroglia - Organisation of Ner...

Neuroglia - Organisation of Nervous System We may refer neuroglia as the connective tissue of the nervous system. It involves all elements of the nervous system other than ne

Postparturient haemoglobinuria, Post pa r turient haemoglobinuria It...

Post pa r turient haemoglobinuria It is also known as puerperal haemoglobinuria or nutritional haemoglobinurea and results in intravascular haemolysis, haemoglobinuria and a

Stage of meiosis, briefly describe the eggs and follicles, in rabbit

briefly describe the eggs and follicles, in rabbit

Left border of the heart, Connect point A and D by line which is convex to ...

Connect point A and D by line which is convex to the left. The left border is formed by the left ventricle except at its upper end which is formed by the left auricle where there i

Describe about acyanotic congenital heart disease, Describe about Acyanotic...

Describe about Acyanotic Congenital Heart Disease ? The following lesions will be discussed here: Left to right shunts: Atrial Septal Defect (ASD), Ventricular Septal Defect

Define basic function of secretin in the digestive process, Q. Where is it ...

Q. Where is it produced and what is the function of secretin in the digestive process? Secretin is made in the duodenum the chyme acidity causes the duodenum to release this ho

Botony, is a wheat plant a eustele or a siphonostele or a protostele?

is a wheat plant a eustele or a siphonostele or a protostele?

Define chronic fever and infection, Chronic fever and  infection Chron...

Chronic fever and  infection Chronic fever  and  infection are always supported will a long standing history of symptoms  or repeated episodes of infection. One of the commonl

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