Transport in Animals

• A transport system is a means by which materials (O_2, CO_2, glucose, amino acids, vitamins, minerals, heat, hormones, plasma proteins, white blood cells and platelets) are moved from an exchange surface to cells located in the organism
• Good transport system: Medium to carry nutrients around the body, pump to push it around, exchange surface to enable O_2 to enter/exit the blood, vessels to carry it by mass flow and two circuits, one to pick up O_2 and the other to deliver it
• There are three main factors that affect the need for a transport system in an organism:

  • Surface area to volume ratio
  • Size
  • Activity level
• Closed Circulatory System - The fluid is always contained within vessels
• Double Circulatory System - A separate systemic and pulmonary circulation; blood passes through the heart twice per circuit of the body
• Haemolymph - A fluid, analogous to the blood in vertebrates, that circulate in the interior of an arthropod (invertebrate) body, remaining in direct contact with the animal’s tissues
• Open Circulatory System - Fluid (haemolymph in arthropods) flows through a body cavity
• Pulmonary Circulation - A blood circuit that flows from the heart to the lungs and back to the heart
• Single Circulatory System - Circulatory system with a combined systematic and exchange surface circulation blood flows once through the heart per circuit of the body
• Systemic Circulation - A blood circuit that flow from the heart to the rest of the body and back to the heart