Question

please 4 questions please

4. Understand the purpose (and advantages) of a double circulation ("2 pump” circulatory system) 5. Be able to describe all the events (steps) that occur during a cardiac cycle for mammals. This includes movement of blood through the heart, lungs and other tissues, as well as the opening and closing of all heart valves, and the signals arising from the SA and AV nodes. 6. How does hypertension develop, and how is it detrimental to health long-term? 7. Be familiar with the 3 physical conditions that can optimize rate of diffusion of a gas across a membrane (conceptualized in Fick's Law of Diffusion), and understand ways that animal respiratory systems have evolved in order to maximize the exchange of o and CO2 across their membranes.

Answer 1

Birds and mammals have a completely divided ventricle,therefore their heart is completely four chambered i.e.,they have two auricles and two ventricles.

Left auricle receives oxygenated blood from lungs and pours into left ventricle. And the left ventricle pumps it to the entire body through systematic circulation.

Right auricle receives deoxygenated blood which returns from the body and pour it into right ventricle which pumps it to lungs for reoxygenation. As there is two circulation (left and right), therefore this type of circulation is called double circulation.

Advantages of double circulation :

In double circulation, there is no mixing of oxygenated and deoxygenated blood at all.

This separation allows a highly efficient supply of oxygen to the body.

Blood can be pushed to the body at a higher pressure,therefore higher blood pressure is maintained.

There is a greater flow of blood to the tissues.