TRANSPORTATION OF MATERIAL IN LIVING THINGS

2.4.0 Transport of materials in living things

2.4.1 Concept of transport of materials

(Not found in any exams)

2.4.2 Diffusion, osmosis and mass-flow

Osmosis - Passage of molecules through a semi-permeable membrane from a weak to a strong solution Diffusion - The movement of molecules of liquids or gases in regions where they are highly concentrated

until they are equally distributed

Osmotic Potential - The pressure which molecules could diffuse from a solution if it were separated from another solution by a semi-permeable membrane

Concentration Gradient - Represents the difference in concentration of a substance between two places Plasmolysis - The shrinking of a cells cytoplasm due to the loss of water by osmosis

Mass Flow - The movement of fluids through a vessel or tube without passing through a membrane Difference between osmosis and diffusion - Osmosis involves the movement of water molecules from a

low concentration to a highly concentrated region, whereas diffusion is the movement of molecules of from a highly concentrated region to a lowly concentrated one

Hypertonic Solution - A solution which has more solute in concentration and less water molecules Effects on a cell - It will lose water by osmosis and as a result will undergo flaccidity

Hypotonic Solution - A solution which has more concentration of water molecules and less solute Effects on a cell - The solution is more diluted, so it will absorb water from its surrounding resulting in

the cell undergoing turgidity

2.4.3 Transport of materials in mammals

2.4.3.1 Structure of the mammalian heart

Aorta - The largest artery in the body which originates from the left ventricle and extends down the

abdomen distributing oxygenated blood to all parts of the body Coronary Artery - Maintain blood flow in the heart muscle

Diastolic Blood Pressure - Causes blood from contracting auricles to flow into ventricles

Inferior (Posterior) Vena Cava - A large vein which carries deoxygenated blood from the posterior half of

the body to the right atrium of the heart

Pulmonary Artery - Arteries which carry blood from the heart to the lungs Pulmonary Vein - A large blood vessel which

carries blood from the lungs to the left atrium of the heart

Semi-lunar Valve - Pocket like valves in the main arteries at the point where they leave the heart whose purpose is to stop blood from flowing back into the ventricles

Superior Vena Cava - The vein which carries deoxygenated blood from the upper half of the body to the right atrium of the heart

Systolic Blood Pressure - Causes blood from contracting ventricles to flow into pulmonary arteries and the aorta

Vena Cava - The main vein of the body Ventricle - One of the large thick walled lower

chambers of the heart that pumps blood into arteries

Four chambers of the heart - Left atrium, right

atrium, left ventricle, right ventricle

Right Atrium - Receives deoxygenated blood from the superior and inferior vena cava and pumps it into the right ventricle through the tricuspid valve

Left Atrium - Receives oxygenated blood from the pulmonary veins and pumps it into the left ventricle Left Ventricle - Receives oxygenated blood from the left atrium vial the bicuspid (mitral) valve and

pumps it into the aorta via the aortic valve

Right Ventricle - Receives deoxygenated blood from the right atrium via the tricuspid valve and pumps it into the pulmonary artery via the pulmonary valve

Types of heart valves - Atrioventricular (AV) valves, semilunar (SL) valves Atrioventricular Valves - Valves between the atria and the ventricles

Types of Atrioventricular Valves - Bicuspid (mitral), tricuspid

Tricuspid Valve - A valve on the right side of the heart between the right atrium and right ventricle

Bicuspid (Mitral) Valve - A dual-flap valve in the heart which lies between the left atrium and

the left ventricle

Semi-lunar (Heart) Valve - Allows blood to flow through in one direction leaving the heart Types of Semi-lunar Valves - Aortic valve, pulmonary valve

Aortic Valve - The valve which lies between the left ventricle and the aorta

Pulmonary Valve - The valve which lies between the right ventricle and the pulmonary artery Heart Attack - A sudden stoppage of the heart beat which is commonly caused by a blockage of a coronary

artery due to thrombosis