Question

1)

Which of the following describes the pathway of the systemic circuit in bird and mammal circulation? Select one: heart> lungs> heart heart> body> heart body> lungs>heart body> heart> lungs> heart

2)

3) choices are( veins or arteries or capillaries )

Answer 1

1.ANS:B option

Because Birds and mammals having 4 chambered heart, and heart is having 2 seperate pumps The left side of heart pumps systemic circulation and right side of heart pulmonary circulation.

Systemic circulation: The flow blood away from heart to the Brain, liver, kidney and other organs and then the return of this blood to the heart.

Pulmonary circulation: The flow of blood away from heart through lungs where oxygenated occurs and then returns to heart again.

Here in the question they are asking about systemic circulation.

2.Option A

Artery(Few)-Arteiole(More)- capillary(Most)

The rate of blood flow in vessels is inversely proportional to Total surface area, Reduced diameter of the blood vessel lumen that accounts for the increased frictional resistance so reduced rate of blood in capilaries.

3.Arteries is being pushed round by heart ventricular contraction, the hrdrostatic pressure force exerted by a blood pushes against the inside of the artery walls, this pushing is your blood pressure.opening and closing arteries affect the blood pressure,the more narrow in arteries less space to blood flow and harder it pushes against the artery walls.

4. veins carry blood vessel that carry blood towards heart ,they have thin non elastic muscular walls, valves are present to prevent back flow against gravity,Veins operate a low blood pressure, they carry blood forward when pushed and veins have less mucular activity than arteries.