Internal Flúids and Respiration

• Sponges, Cnidarians, and Flatworms do not have circulatory system because their body wall is very thin.
• Cells in invertebrates are either part of an external layer, or they line the gastrovascular cavity
• Each cell lining the external layer gastrovascular cavity is exposed to water and can independently exchange gases and rid itself of wastes.
• The circulatory system transports oxygen and nutrients, such as glucose and amino acids, to the cells.
• Transport in invertebrates with circulatory system has Open Circulatory system. consists hemolymph, blood vessels and open spaces
• in open circulatory system. The heart pumps hemolymph via vessels into tissue spaces, then hemolymph drains back to the heart.
• In the open circulatory system in grasshopper, the dorsal tubular heart pumps hemolymph into a dorsal aorta, which empties into the hemocoel.
• The hemolymph of a grasshopper is colorless because it does not contain hemoglobin or any other respiratory pigment. It carries nutrients but no oxygen.
• Oxygen is taken to cells, and carbon dioxide is removed from them by way of air tubes called tracheae
• tracheae are found throughout the body. It also provide efficient transport and delivery of respiratory gases. Air enters their body via spiracles.
• Closed circulatory System consists blood and blood vessels. examples are squid, octopus, earthworms.
• in closed circulatory system. The blood is pumped by the heart into a system of blood vessels. Valves prevent the backward flow of blood.
• in closed circulatory system. Both gas exchange and nutrient-for-waste exchange occur across the capillary walls.
• in closed circulatory system. After leaving a capillary, blood moves from small veins into the dorsal blood vessel (a vein). This dorsal blood vessel returns blood to the heart for repumping.
• The earthworm has red blood that contains the respiratory pigments hemoglobin. It has no specialized organ, such as lungs, for gas exchange with the external environment.
• the gas exchange in earthworms takes place across the body wall, which must always remain moist for this purpose.
• transport in Vertebrates. All vertebrate animals have closed circulatory system, It is called cardiovascular system.
• Cardiovascular system consists of a strong, muscular heart in which the atria (sing. atrium) receive blood and the muscular ventricles pump blood through the blood vessels.
• three kinds of blood vessels in vertebrates are arteries, capillaries, and veins.
• arteries - carry blood away from the heart
• Capillaries - exchange materials with tissue fluid
• veins - return blood to the heart
• Circulatory pathways in Fish. One-circuit/single-loop circulatory pathway. the pumping action of the ventricle sends blood under pressure to the gills, where gas exchange occurs.
• two-circuit/double-loop circulatory pathway. The heart pumps blood to the tissues, called a systemic circuit, and also pumps blood to the lungs called pulmonary circuit. This double pumping action is an adaptation to breathing air on land.
• In amphibians, the heart has two atria and a single ventricle. The sinus venosus collects 02-poor blood returning via the veins and pumps it to the right atrium
• In all birds and mammals, as well as crocodilians, the heart is divided into left and right halves.
• The heart of all birds, mammals, and crocodilians have right ventricle (pumps blood to the lungs) and left ventricle (pumps blood to the rest of the body)
• The arrangement of circulatory pathways in vertebrates provides adequate blood pressure for both the pulmonary and systemic circuits.
• The earthworm have 5 hearts and it's called aortic arches
• Oxygen poor blood. The blood is already used by the body
• Oxygen rich blood. The blood fresh from lungs and is carrying an oxygen.
• Blue = veins = oxygen poor blood
• red = aorta = oxygen rich blood
• when heart contracts, opening called ostia is closed. When heart is relaxed, hemolymph is sucked back into the heart