Transport In Animals Flashcards
Open Circulatory System
. Blood pumped into body cavity . Don’t have a capillary System . Tissue surrounded by blood . Doesn’t transport gas . Can’t control volume of blood . Slow blood flow
Closed circulatory System
. Blood pumped by heart through vessels . Have a capillary System . Blood not directly in contact with tissue . Transports gases . Blood volume controlled by vessels . Rapid blood flow
Role of arteries
Carrying oxygenated blood away from the heart to the rest of the body (under high pressure)
Structure of arteries
. Lumen surrounded by endothelium (smooth allows blood to flow in a straight line)
. 2nd Layer contains smooth muscle and elastic fibres ( M=Gives Structure and allows vasoconstriction, E=Allows artery to expand and recoil)
Role of capillaries
Where exchange between cells and the circulatory system takes place. Need to be good at diffusion
Structure of capillaries
. 1 cell thick (short diffusion distance)
. Large SA (large cross section)
. Lumen 1 RBC thick (inc chance of exchange)
Hydrostatic pressure
Pressure within the blood from the from the beating heart pushing substances out of the capillary into the tissue fluid
Oncotic Pressure
Pressure pushing/pulling substances. Caused by the presence of protein inside capillaries which give the inside of the capillary a negative WP meaning water will move in
Pressures arterial end
Hydrostatic=High (As heart comes in direct contact to heart and blood so blood under HP)
Oncotic Pressure= Low (As the water has not yet moved out of the capillary and there are the same number of proteins)
Pressure Venous End
Low Hydrostatic Pressure (Pressure in veins isn’t high so substances are not being pushed out of the capillary
High Onocotic Pressure (As water in the tissue fluid is attracted to proteins in the capillary, this causes water to move form the tissue fluid into the capillary)
