Question

What are some examples of open circulatory systems? How does the open circulatory system work?

Answer 1

Open circulatory system:

1. The open circulatory system has blood and interstitial fluid mixed called hemolymph that flows freely within the body cavity called hemocoel.
2. Approximately 90% of the hemolymph is composed of amino acids, sugars, proteins, inorganic ions, etc., and 10% contains hemocytes.
3. It is important to note that the tracheal system and not the circulatory system is involved in the delivery of oxygen.
4. The open circulatory system is found in arthropods such as insects and mollusks such as snails and octopuses.

Working of the open circulatory system:

1. The dorsal vessel, also known as the heart, is divided into chambers separated by Ostia.
2. The alary muscles attached laterally to each chamber contract to push the hemolymph from one chamber to the other.
3. When the alary muscles relax, the Ostia opens to allow the entry of hemolymph from the hemocoel.

Functions of the open circulatory system:

1. It is responsible for transporting nutrients, hormones, etc. to different parts of the body and also removing waste from the body.
2. Hemocytes aid in clotting that helps to heal wounds, and phagocytose pathogens.
3. Blood helps in thermoregulation.
4. The hydrostatic pressure of blood during muscle contraction helps in processes such as hatching, molting, and reproduction.