Question

1.  What are the two main circuits of the cardiovascular system? For each circuit identify the general structures found within the circuit and the status of the blood found throughout that circuit.

2.  For the condition of hypotension, identify 2 possible causes and the predicted effect on cardiac output. How would the body respond to this condition? Be sure to explain your answer in the context of a homeostatic feedback loop, and to identify if reactions are local or reflex control.

3.  For the condition of hypertension, identify 2 possible causes and the predicted effect on cardiac output. How would the body respond to this condition? Be sure to explain your answer in the context of a homeostatic feedback loop, and to identify if reactions are local or reflex control.

4.  What is the role of blood volume in the long term regulation of arterial pressure?

5. In the case of rapid blood loss, do you expect that heart rate to increase or decrease? Why?

Answer 1

1) Two main circuits are- systemic circuit and pulmonary circuit.

The general structure of systemic circuit= left ventricle - the aorta - systemic arteries - systemic capillaries - systemic vein - inferior and superior vena cava - right atrium.

The general structure of the pulmonary circuit= right ventricle - pulmonary artery - lung's capillaries - pulmonary vein - left atrium.

Blood status in systemic circuit= oxygenated blood from the left ventricle to systemic capillaries and deoxygenated blood from systemic capillaries to the right atrium.

Blood status in pulmonary circuit = deoxygenated blood from the right ventricle to the lung's capillaries and oxygenated blood from the lung's capillaries to the left atrium.

2) Hypotension means low blood pressure. Cause of hypotension can be dehydration because, in dehydration blood volume decrease and how blood volume put an effect on Bp, I already explained in 4th no question's answer.

Another reason can be a low concentration of sodium ion. A low concentration of sodium can also lead to a low volume of blood beacuse in this condition fluid enter into the cell from the vessels.

In the hypotension cardiac output decrease because in the hypotension blood volume decrease.

3) Hypertension means high blood pressure. Hypertension just the opposite of hypotension so the excess amount of water taking and an excess amount of sodium ion can lead to hypertension.

In the hypertension cardiac output increase due to an increase in blood volume.

4) Blood volume is very important for maintaining arterial blood pressure. If blood volume increases, more amount of blood will reach the heart. For this stroke volume will be ( AMOUNT OF BLOOD THAT IS PUMP BY THE HEART WITH EACH STROKE) increased and obviously, cardiac output will also increase and due to increased cardiac output arterial blood pressure will also increase. Similarly, if blood volume decreases, cardiac output will decrease and pressure on the arterial wall also decreases.

5) Rapidly blood loss will increase the heart rate. Because due to blood loss, arterial blood pressure decrease. and blood flow is also decreased to the organs. That is why the heart beats faster so that it can pump more amount of blood and the proper amount of blood can reach the organs.