Circulatory System: Mollusca
Most animals within the Mollusca Phylum have an open circulatory system. Cephalopods have a closed circulatory system. Within a open circulatory system blood is not restricted to circulating within the blood vessels. Open circulatory systems which have evolved through species such as crustaceans, insects, mollusks, and other invertebrates, pump blood into a hemocel with the blood extending back to the circulatory system betweens the various cells. Blood within a open circualtory system is pumped by a heart into the body cavities, where tissues are surrounded by blood. There are various animlas that fit the requirments of the Mollusa Phylum.
One animal within the Mollusa Phylum is a Snail. A Snail has an open circulatory system which means that blood is not restricted from travelling within the blood vessels. The heart of the snail is found on the left side of the body and is made up of one auricle and one ventricle. The ventricle pumps blood through an aortic trunk to all parts of the body through a group of arteries and capillaries. From the capillaries the blood flows into various spaces in the tissues called the hemocoel. From the hemocoel blood passes into the veins and back to the auricle. The blood present in snails contains a fused compound known as hemocyanin which purpose is to transports oxygen. Hemocyanin is similar to hemoglobin which is found in human blood.
Another animinal within the Mollusca Phylum is a Slug. Slug's and Snail's have a very similar circulatory system. The fluid that is transported through the circulatory system of a Slug is called hemolymph. Hemolymph is a fluid in the circulatory system and is similar to the fluids and cells making up both blood and interstitial fluid including water, proteins, and fats. Hemocyanin is present in the hemolymph as the respiratory pigment within the circulatory system of a Slug. Hemocyanins are respiratory proteins in the form of metalloproteins containing two copper atoms that reversibly bind a single oxygen molecule.
A third animal within the Mollusa Phylym is a Chiton. A Chiton is a small ovular species with eight plates on its dorsal side, and an open ciculatory system. The artery takes the blood to the tissue, where it returns to the heart via a vein. In advanced animals, like humans, the blood goes from the heart to an artery, to a capillary (the name for a very small blood vessel) to the cells and back to the heart through a vein. This is important because as a rule, creatures with open circulatory systems aren't all that large.
One animal within the Mollusa Phylum is a Snail. A Snail has an open circulatory system which means that blood is not restricted from travelling within the blood vessels. The heart of the snail is found on the left side of the body and is made up of one auricle and one ventricle. The ventricle pumps blood through an aortic trunk to all parts of the body through a group of arteries and capillaries. From the capillaries the blood flows into various spaces in the tissues called the hemocoel. From the hemocoel blood passes into the veins and back to the auricle. The blood present in snails contains a fused compound known as hemocyanin which purpose is to transports oxygen. Hemocyanin is similar to hemoglobin which is found in human blood.
Another animinal within the Mollusca Phylum is a Slug. Slug's and Snail's have a very similar circulatory system. The fluid that is transported through the circulatory system of a Slug is called hemolymph. Hemolymph is a fluid in the circulatory system and is similar to the fluids and cells making up both blood and interstitial fluid including water, proteins, and fats. Hemocyanin is present in the hemolymph as the respiratory pigment within the circulatory system of a Slug. Hemocyanins are respiratory proteins in the form of metalloproteins containing two copper atoms that reversibly bind a single oxygen molecule.
A third animal within the Mollusa Phylym is a Chiton. A Chiton is a small ovular species with eight plates on its dorsal side, and an open ciculatory system. The artery takes the blood to the tissue, where it returns to the heart via a vein. In advanced animals, like humans, the blood goes from the heart to an artery, to a capillary (the name for a very small blood vessel) to the cells and back to the heart through a vein. This is important because as a rule, creatures with open circulatory systems aren't all that large.