Annelida
The Annelida phylum is made up of animals with a closed circulatory system. Annelida animals have blood that only circulates within the blood vessels and through the heart. There are over 17,000 modern species in the Annelida phylum. Most Annelida animals are marine animals; they are generally from tidal zones to hydrothermal vents, in fresh water and in moist. Most Annelida animals have a closed circulatory system. Animals within the Annelida phylum have different, varying characteristics. The blood of Annelida animals generally are composed of hemoglobin, a red oxygen-carrying pigments. Some Annelida animals have a green oxygen-carrying pigment, and others have unpigmented blood. Some of the lateral vessels are contractile and serve as hearts. The hearts and the dorsal vessel have valves that prevent back-flow.
An example of an Annelida animal is a leech. Annelida animals have low-pressure phases. In these phases, contractions occur, which are responsible for continuing the blood supply to the capillary networks of the organs and the body wall, with the possible exception of the intestine. The high pressure phases of contractions cause a forward bloodflow within the lateral vessel. The dorsal and ventral vessels are longitudinal vessels. The dorsal vessel takes blood from the capillary networks of the organs and releases it into both the intestinal capillaries and the caudal laterodorsal vessels. Two lateral vessels also run along the entire length of the animal.
The Ragworm is also an Annelida animal. The Ragworm has a closed circulatory system. They have blood vessels which the blood flows. There are two longitudinal blood vessels: dorsal and ventral. These vessels contain muscles on their perimeter. These muscles can contract to keep blood circulating across the body. Blood flows across the entire body in the ventral vessel and returns in the dorsal vessel. In each segment, a number of smaller vessels branch off from the main vessels to supply the sections of that segment with the necessary blood.
Another Annelida animal is the Lugworm. Lugworms are a type of segmented worm. The lugworm is also referred to as the "sandworm" because they live under the sand. Generally, they don't go above ground. Lugworms contain a closed circulatory system. The Lugworm receives its oxygen from the sand. Similarly, earthworms receive their oxygen from the soil.
An example of an Annelida animal is a leech. Annelida animals have low-pressure phases. In these phases, contractions occur, which are responsible for continuing the blood supply to the capillary networks of the organs and the body wall, with the possible exception of the intestine. The high pressure phases of contractions cause a forward bloodflow within the lateral vessel. The dorsal and ventral vessels are longitudinal vessels. The dorsal vessel takes blood from the capillary networks of the organs and releases it into both the intestinal capillaries and the caudal laterodorsal vessels. Two lateral vessels also run along the entire length of the animal.
The Ragworm is also an Annelida animal. The Ragworm has a closed circulatory system. They have blood vessels which the blood flows. There are two longitudinal blood vessels: dorsal and ventral. These vessels contain muscles on their perimeter. These muscles can contract to keep blood circulating across the body. Blood flows across the entire body in the ventral vessel and returns in the dorsal vessel. In each segment, a number of smaller vessels branch off from the main vessels to supply the sections of that segment with the necessary blood.
Another Annelida animal is the Lugworm. Lugworms are a type of segmented worm. The lugworm is also referred to as the "sandworm" because they live under the sand. Generally, they don't go above ground. Lugworms contain a closed circulatory system. The Lugworm receives its oxygen from the sand. Similarly, earthworms receive their oxygen from the soil.