Question

Systemic heart refers to
a. the heart that contracts under stimulation from the nervous system.
b. left auricle and left ventricle in higher vertebrates.
c. entire heart in lower vertebrates.
d. the two ventricles together in humans.

Answer 1

The circulatory system consists of the heart and the blood vessels that transport blood throughout the body. The vertebrates exhibit double circulation of blood namely systemic and pulmonary circulation.

Complete answer:
Circulatory system- The circulatory system is constituted by the heart and the blood vessels. They convey blood throughout the body. Blood carries oxygen from the air we breathe into cells throughout the body. Types of Circulation: Pulmonary Circulation and Systemic Circulation
During pulmonary circulation, blood moves between the heart and the lungs. The deoxygenated blood is transported to the lungs to intake oxygen and release carbon dioxide. The oxygenated blood returns to the heart. Between the heart and the rest of the body, blood is transported by the Systemic circulation. It sends oxygenated blood to the cells and returns deoxygenated blood to the heart. The circulatory and respiratory systems work together to sustain the body with oxygen and to get rid of carbon dioxide. Pulmonary circulation facilitates the method of external respiration.
Deoxygenated blood flows into the lungs. It absorbs oxygen with the help of the alveoli and exhales carbon dioxide. Systemic circulation facilitates internal respiration since oxygenated blood flows into capillaries. The blood diffuses respiratory gas as oxygen into cells and absorbs out carbon dioxide from it. In the pulmonary circulation, deoxygenated blood exits the right ventricle of the heart and reaches the lungs for purification. The pulmonary veins transport oxygenated blood to the left atrium. The pulmonary arteries are the sole arteries that carry deoxygenated blood, and the pulmonary veins are the sole veins that carry oxygenated blood. In the systemic loop, oxygenated blood is pumped from the left ventricle of the heart through the aorta, the largest artery within the body. In veins, arterioles, oxygen and nutrients are released and carbon dioxide and other waste substances are absorbed. The systemic veins feed into the inferior and superior venae cavae, the largest veins within the body.

So, the correct answer is (B) left auricle and left ventricle in higher vertebrates.

Note: Systemic circulation begins with the heart pumping oxygenated blood out of the left ventricle and into the aorta. After the blood supply to cells with oxygen and nutrients, it returns deoxygenated blood to the right atrium of the heart. The deoxygenated blood returns from the right atrium to the right ventricle. The heart then pumps it out of the right ventricle and into the pulmonary arteries to start pulmonary circulation. The blood moves to the lungs, exchanges carbon dioxide for oxygen, and returns to the left atrium of the heart. The oxygenated blood transports from the left atrium of the heart to the left ventricle below, to start systemic circulation again.