BIO310H5 Study Guide - Circulatory System, Vasoconstriction, Bradykinin
Document Summary
Transport of: nutrients, oxygen, wastes (e. g. co2, nitrogenous waste, hormones. Homeostasis involved in the regulation of: inorganic substances and fluid balance, body temperature. Arterial system- distributes blood throughout body and acts as pressure reservoir. Capillaries- transfer of materials between blood and tissue. Venous system- returns blood to heart and acts as blood reservoir. Blood vessels empty into hemocoel (20-40% of body volume: hemolymph bathes tissues directly. Blood flows in a continuous circuit of tubes (systemic & pulmonary) Blood volume in closed circulation is 5-10% of body volume, but same extracellular space as hemocoel in invertebrates. Vessels in peripheral circulation are adapted for the functions they serve. Arterial system acts as a conduit and a pressure reservoir: If cardiac output increases, arterial blood pressure increases. If capillary flow increases, arterial blood pressure will fall. Conduit pressure reservoir damping oscillation control of flow distribution. There is considerable variation in extent in which pulmonary and systemic circuits are separated in air breathing vertebrates.
