CIRCULATORY SYSTEM QUIZ

1. What is circulation?

Circulation is the movement of substances like nutrients and gases within blood vessels and cavities throughout the organism.

What are the two types of circulatory systems?

The circulatory systems can be classified into open circulatory system and closedcirculatory system.

What is an open circulatory system?

Open circulatory system is the one in which blood does not circulate only inside blood vessels but it also falls in cavities that irrigate tissues. In the open circulatory system the blood pressure is low and generally the blood (called hemolymph) has low cellularity.

Arthropods, molluscs (the cephalopods are exception) and protochordates have open circulatory system.

What is a closed circulatory system?

A closed circulatory system is one in which blood circulates only inside blood vessels. For this reason the blood pressure is higher in animals with closed circulatory system. The cellularity of the blood is also higher with many specific blood cells.

The closed circulatory system is a feature of annelids, cephalopod molluscs and vertebrates.

What are the advantages of the closed circulatory system over the open circulatory system?

The closed circulatory system is more efficient. Since blood circulates only inside blood vessels it can do it with more pressure reaching farther distance.

What are the typical components of a closed circulatory system?

The typical components of the closed circulatory system are the blood vessels within which blood circulates (arteries, veins and capillaries), a pumping organ (heart) and the blood or bloodlike fluid.

What is the difference between systole and diastole

Systole and diastole are the two stages into which the cardiac cycle is divided. Systole is the stage when the contraction of ventricular muscle fibers occurs and the ventricles are emptied. Diastole is the stage of the cardiac cycle when the ventricular muscle fibers distend and the ventricles are filled with blood.

What are arterial vessels, arteries and arterioles?

Arterial vessels are every blood vessel that carries blood from the heart to the tissues. Arteries and arterioles are arterial vessels. Arterioles are thin arteries that end in capillarie.

What are venous vessels, veins and venules?

Venous vessels are every blood vessel that carries blood from the tissues to the heart. Veins and venules are venous vessels. Venules are thin veins that are continuous to capillaries.

What are the capillaries of the vascular system?

Capillaries are small blood vessels that perform exchange of substances between the blood and the body tissues. Capillaries are neither arteries nor are they veins since they have distinct features.

In capillaries the wall is made of a single layer of endothelial cells through which substances are exchanged. These vessels receive blood from the arterioles and drain to the venules.

What are the valves of the venous system? What is their function?

The valves of the venous system are structures inside the veins that permit blood to flow only in the normal way (from the tissues to the heart) and forbid it to return in the reverse way in favor of gravity.

What are varices?

Varix means abnormal enlargement of veins. Varices occur when excessive pressure against the normal blood flux creates enlargement of the vein and thus insufficient functioning of its valves (venous insufficiency).

What is the lymphatic system?

The lymphatic system is a network of specialized valved vessels that drain interstitial fluid (lymph). The lymphatic system is also responsible for the transport of chylomicrons (vesicles that contain lipids) made after the absorption of fats by the intestinal epithelium.

Which are the heart chambers respectively where the entrance and the exit of blood occur

The heart chambers through which blood enters the heart are the atria. There are the right atrium and the left atrium.

The heart chambers through which the blood exits the heart are the ventricles. There are the right ventricle and the left ventricle.

Concerning the thickness of their walls how different are the heart chambers?

The left ventricle is more muscular than the right ventricle because pumping blood to the lungs (the right ventricle task) is easier (needs less pressure) than pumping blood to the other tissues of the body (the left ventricle task).

What is vena cava? Which type of blood circulates within the vena cava?

The vena cava are either of two large veins that debouch into the right atrium. The superior vena cava drains all blood that comes from the head, the superior limbs, the neck and the superior portion of the trunk. The inferior vena cava carries blood drained from the inferior portion of the trunk and the inferior limbs.