Question

What is false about closed circulatory system? (a) Blood pressure is high and regular (b) Amount of blood is limited (c) Blood circulates through arteries, veins and capillaries (d) Blood pressure is low and irregular

Short answer

The false statement about the closed circulatory system is (d) - Blood pressure is low and irregular.

Step-by-step solution

Analyze Option (a)

Firstly, check the statement (a): 'Blood pressure is high and regular'. In a closed circulatory system, the blood is under pressure because it is pumped by the heart and the blood pressure tends to be high and regular. Therefore, this statement is true.

Analyze Option (b)

Look at the statement (b): 'Amount of blood is limited'. This is true, because the blood in a closed system is contained within a network of blood vessels, and the volume of blood that can be contained within these vessels is finite. Therefore, this statement is correct.

Analyze Option (c)

Now move on to statement (c): 'Blood circulates through arteries, veins and capillaries'. This statement is indeed accurate for a closed circulatory system where blood is always enclosed in blood vessels like arteries, veins, and capillaries. So, this statement is true.

Analyze Option (d)

Finally, consider statement (d): 'Blood pressure is low and irregular'. In a closed circulatory system, due to the pumping of the heart, blood pressure is typically high and regular, making this statement false.

Key concepts

blood pressure

Blood pressure is the force that the circulating blood exerts on the walls of blood vessels. It is an essential aspect of the closed circulatory system because it ensures that blood reaches various parts of the body efficiently. Without adequate pressure, oxygen and nutrients cannot be delivered effectively.
In a closed circulatory system, the heart plays a crucial role in maintaining high and regular blood pressure by continuously pumping blood through arteries. This consistency allows the body to function properly, supporting active tissues and organs.

• High blood pressure: Key for delivering nutrients and oxygen.
• Regular blood pressure: Vital for overall body homeostasis.

When blood pressure is too low or irregular, it can lead to impaired circulation and diminished organ function. This is why a stable blood pressure is a hallmark of a healthy closed circulatory system.

arteries, veins, capillaries

Arteries, veins, and capillaries form the complex network of blood vessels within a closed circulatory system. These vessels are responsible for the transport of blood to and from the heart and different parts of the body.

• Arteries: Thick-walled vessels that carry oxygen-rich blood away from the heart under high pressure. They are strong and elastic to accommodate and maintain blood pressure.
• Veins: These carry deoxygenated blood back to the heart at a lower pressure. They have thinner walls than arteries and often contain valves to prevent backflow of blood.
• Capillaries: Tiny blood vessels where the exchange of oxygen and nutrients for waste materials occurs. Their thin walls allow for this vital exchange at the cellular level.

Together, these vessels ensure that blood circulates efficiently throughout the body. This network is crucial for maintaining the high pressure needed in a closed circulatory system.

heart pumping

The heart is the powerhouse of the closed circulatory system, responsible for the continual movement of blood through the vessels. It consists of chambers that rhythmically contract to push blood, creating the driving force for circulation.
The heart works in a cycle. With each contraction, it pumps blood into arteries, setting the blood in motion under pressure. This consistent action maintains the regular flow of blood and thus regular blood pressure.

• Pumping mechanism: Heart contracts (systole) to push blood and relaxes (diastole) to fill with blood, ensuring a steady heartbeat.
• Role in blood pressure: Through constant pumping, the heart maintains the high blood pressure that is essential for efficient circulation.

The heart's predictable pumping supports the eventual distribution of oxygen and nutrients to tissues, highlighting its integral role in the closed circulatory system.