Question

A major advantage of a double circulation is that a. blood can be pumped to the upper portions of the body by one circuit and to the lower portions of the body by the other circuit. b. each circuit can pump blood with differing pressures to optimize the function of each. c. the oxygenated blood can mix with the deoxygenated blood before being pumped to the tissues of the body. d. less energy is required to provide nutrients and oxygen to the tissues of the body. e. All of the above are advantages of a double circulation.

Short answer

The correct answer is option B. Each circuit in a double circulation can pump blood with differing pressures to optimize the function of each circuit.

Step-by-step solution

Analyze the Options

To answer this question, each option should be looked at critically. The key to understanding this is the advantage that a double circulatory system provides over a single circuit.

Evaluate Option A

The first option suggests that one circuit is responsible for upper body and the other for the lower body. However, that's incorrect as both circuits supply blood to the entire body but differ in the type of blood they carry.

Evaluate Option B

The second option states that each circuit can pump blood with differing pressures to optimize the function of each. This is indeed a characteristic of a double circulatory system. The pulmonary circulation carries deoxygenated blood at lower pressure to the lungs where it picks up oxygen. The systemic circulation carries oxygenated blood at high pressure to supply the entire body.

Evaluate Option C

The option that oxygenated blood can mix with deoxygenated blood is not true. A primary function of the double circuit is to separate these two to increase the efficiency of oxygen delivery to the body.

Evaluate Option D

Option D suggests that a double circulatory system requires less energy, which is incorrect. The heart works harder in a double circulatory system to pump blood, hence requires more energy.

Evaluate Option E

Option E suggests that all of the above options are correct. Since Options A, C, and D are incorrect, this can't be correct either.

Key concepts

Circulatory System Function

The circulatory system, an essential part of human physiology, plays a fundamental role in maintaining life. At its core, its main function is to transport blood throughout the body, ensuring that oxygen, nutrients, and hormones reach the cells, and that waste products are carried away.

This biological system is akin to a highway network, where blood vessels act like roads, and the blood that flows within is like the active traffic, tasked with delivery and exchange. The heart, acting as a powerful pump, drives this entire system, pushing blood through the network of vessels to facilitate the exchanges needed for cellular processes.

Double circulation, an advanced feature in mammals, including humans, enhances the efficiency and effectiveness of this transportation. By employing two distinct circuits - the pulmonary and systemic - the system gains the ability to deliver oxygenated blood more efficiently and manage blood pressure according to the specific needs of the lungs and the rest of the body.

Pulmonary Circulation

Pulmonary circulation is one of the two loops in the double circulatory system that addresses the critical task of gas exchange. Starting at the heart, deoxygenated blood is ushered to the lungs via the pulmonary arteries. Here's where the magic of respiration takes a new breath - literally!

In the vast network of the lungs' capillaries, the blood releases carbon dioxide and eagerly absorbs oxygen - a pivotal process ensuring that every cell receives this vital element. Upon saturation with oxygen, blood transforms - it's now oxygenated, and it peacefully returns to the heart through the pulmonary veins, ready for the systemic circuit to take over and deliver this freshly oxygenated blood to the awaiting tissues and organs of the body.

Systemic Circulation

Systemic circulation is the second loop in the double circulatory system, where the main event is the delivery of oxygen-rich blood to the body's myriad of cells. This segment of the circulatory system commences from the left side of the heart, propelling oxygenated blood into the aorta, the largest artery, which then branches out into a tree of smaller vessels reaching the body's furthest corners.

As this nutrient-packed blood trickles through the vast web of capillaries, the cells take up oxygen and nutrients, replacing them with waste such as carbon dioxide. This trade is the lifeline of each cell, ensuring that they can function and contribute to the bigger picture - keeping the body healthy and alive. Once depleted of oxygen, the deoxygenated blood is directed back to the heart through the veins, completing the circuit and ready to embark again on the route to the lungs for a new load of oxygen.

Oxygenated and Deoxygenated Blood Separation

The separation of oxygenated and deoxygenated blood is the hallmark of the double circulatory system, which distinctly enhances the efficiency of vertebrates, especially mammals and birds. This clever biological design ensures that the body's tissues always get a fresh supply of oxygen, rather than a mix of oxygen-rich and oxygen-poor blood.

Intriguingly, this separation is maintained by sophisticated chambers and valves within the heart, which ensure a one-way traffic of blood - preventing the mix-up that could potentially undermine the system's efficiency. The right side of the heart is devoted to receiving deoxygenated blood and pumping it towards the lungs for oxygenation, while the left side exclusively handles oxygenated blood, sending it forth to nourish cells throughout the body. This clear segregation allows for optimal oxygenation of tissues and positions the double circulatory system as a pinnacle of evolutionary enhancements.