EVERYDAY SCIENCE

Detailed explanation-1: -Fish have a closed circulatory system with a heart that pumps blood around the body in a single loop-from the heart to the gills, from the gills to the rest of the body, and then back to the heart. The fishes heart consist of four parts: the sinus venosus, atrium, ventricle, and the bulbus arteriosus.

Detailed explanation-2: -All fishes have closed circulatory system. They also possess a two chambered heart that helps in circulation of blood.

Detailed explanation-3: -Because blood only passes through the heart once in a complete circuit around the body, fishes are said to have a single circulation. One disadvantage is that the narrow gill capillaries slow blood flow, resulting in low blood pressure in the body.

Detailed explanation-4: -A closed circulatory system can have a single or double circulatory pattern. Fish have a single circulatory pattern, wherein the blood passes through the heart only once during each complete circuit. Oxygen-deprived blood from the body tissues comes to the heart, from where it is pumped to the gills.

Detailed explanation-5: -Examples of animals with a closed circulatory system are annelids and vertebrates (including humans). Humans have a cardiovascular system comprised of heart and blood vessels that circulate blood throughout the body and another system for circulating lymph called lymphatic system.