What Is Meant By Open Type Of Circulatory System?
Open circulatory system.In this system, blood flows in spaces for much of the time. Blood does not remain enclosed in the blood vessels and come in direct contact with other body cells and bathes them.There are no typical arteries, veins and capillaries and for much of the time the blood flows in the cavities or sinuses of body cavity (heamocoel) around the viscera (perivisceral sinus) and around the nerve cord (perineural sinus). Exchange of nutrients and waste products between the blood directly baths the tissues. This system does not transport gases. No respiratory pigment and blood is colorless in which nucleated white blood cell float.This is regarded as primitive have lesser efficiency and does not maintain blood pressure. In cockroaches the heart is 13-chambered tubular vessel present in the pericardial sinus and placed in mid dorsal region below terga in abdominal region. The portion of tubular dorsal vessel, which extends in the thoracic and head region I called the “aorta”. I
