INSECT CIRCULATORY SYSTEM DORSAL VESSELS(SALUR DARAH) HEMOCOEL HEMOLYMPH OPEN CIRCULATORY SYSTEM The organ sits in open cavity (haemocoel) filled with insect blood called ‘HAEMOLYMPH’ No arteries, veins or capillaries

The function of circulatory system Transport nutrients to various cells, tissues and organs To carry waste products to the excretory system (malphigian tubules) Provide immunity to harmful organism that enters insect body DOEST NOT TRANSPORT OXYGEN

HEMOLYMPH Consists of: 1) 90% PLASMA: a watery fluid: usually clear, sometimes greenish or yellowish high concentrations of amino acids, proteins, sugars, and inorganic ions.   1) 10% HEMOCYTES: various cell types involved in the clotting reaction, phagocytosis, and/or encapsulation of foreign bodies.   does NOT contain hemoglobin (or red blood cells).   Oxygen is delivered by the tracheal system, not the circulatory system.

MECHANISM OF HEMOLYMPH FLOWS

DORSAL VESSELS (SALUR DARAH) HEART divided segmentally into chambers that are separated by valves (ostia) to ensure one-way flow of hemolymph.   A pair of alary muscles are attached laterally to the walls of each chamber.   Peristalsis: these muscles force the hemolymph forward from chamber to chamber AORTA In front of the heart, lacks valves or muscle.   continues forward to the head and empties near the brain.   Hemolymph bathes the organs and muscles of the head as it emerges from the aorta then back over the alimentary canal,through the body until it reaches the abdomen and re-enters the heart.

CIRCULATORY PATH HAEMOLYMPH FROM BODYENTER OSTIA ( HEART MUSCLE RELAX) PERISTALSIS BATHES HEAD AND ALL ORGANS & BACK TO ABDOMEN AORTA (LACK MUSCLES & VALVE) MOVE FORWARD CHAMBERS (MUSCLE COTRACT)

REMEMBER!!!! DOES NOT CARRY OXYGEN!!! So blood flow is not critical like us human

INSECT CIRCULATORY SYSTEM CLICK THE YELLOW BOX The roles hemolymph Open circulatory system hemocoel Dorsal vessel aorta Heart ostia