Mass transport

• Left Atrium

  The chamber of the heart that holds oxygenated blood from the pulmonary vein

  
• Left Ventricle

  The chamber of the heart that holds oxygenated blood that is forced in from the atrium

  
• Right Atrium

  The chamber of the heart that holds deoxygenated blood from both vena cava

  
• Right Ventricle

  The chamber of the heart that holds deoxygenated blood that is forced in from the atrium

  
• Atrioventricular Valves

  The valves that separate the atria from the ventricles

  
• Semi-Lunar Valves

  The valves that separate the ventricles from the arteries

  
• Aorta

  The artery that transports blood from the ventricle to the entire body

  
• Pulmonary Vein

  The vein that carries oxygenated blood to the heart

  
• Pulmonary Artery

  The artery that carries deoxygenated blood to the lungs

  
• Vena Cava

  The vein that carries deoxygenated blood to the heart

  
• Diastole

  Complete relaxation of the heart. This lowers the pressure in the heart which allows for blood to flow into the atria and partially trickle into the ventricles (due to relaxed atrioventricular valves)
• Sinoatrial Node

  The electrical impulse that is sent across the atria of the heart, stimulating atrial systole
• Atrial Systole

  The process where the atria contract, this decreases the volume of the atria and increases the blood pressure in the atria, forcing the atrioventricular valves open. This allows blood to flow into the ventricles, where the pressure is lower
• Atrioventricular Node

  The electrical impulse that is sent down the centre of the heart, across the bundle of his and to the purkinje fibres of the heart, stimulating ventricular systole
• Ventricular Systole

  The process where the ventricles contract, this decreases the volume of the ventricles and increases the blood pressure in the ventricles, forcing the semi-lunar valves open. This allows blood to flow into the main arteries, where the pressure is lower
• Closing of Valves

  The process that occurs when there is higher pressure in the ventricles or the arteries to prevent any back flow of blood
• Myogenic

  Muscle contraction that is normal for the body and unaffected by chemicals in the brain
• Blood Pressure


  A measurement showing the ratio of systolic pressure to that of diastolic pressure

  
• Systolic Pressure

  When measuring blood pressure, the numerator represents this type of pressure

  
• Diastolic Pressure

  When measuring blood pressure, the denominator represents this type of pressure. The higher this value is, the higher the overall blood pressure

  
• Cardiac Output

  Heart rate x Stroke volume

  Can be measured using graphs like the one shown

  
• ECG

  Electro-cardiogram. This measures the electrical activity of the heart to ensure that everything is working appropriately

  
• P

  The point of the graph which represents atrial systole

  
• QRS Complex


  The point on the graph which represents ventricular systole

  
• T

  The point on the graph which represents ventricular re-polarisation - the recovery of ventricular walls where neurons revert to their original charges

  
• QT Interval

  The point on the graph which represents the contraction time of the ventricles

  
• Myocardial Infarction


  A heart attack, can be due to platelets sticking to ruptured artery plaque
• Coronary Heart Disease

  A disease where the coronary artery is more likely to be blocked, causing myocardial infarction
• Double Circulatory System

  A system where blood is confined to blood vessels and pass through the heart twice, to maintain blood pressure in large animals
• Single Circulatory System

  A system where blood is not confined to blood vessels and only passes through the heart once, smaller animals have this system
• Mass Transport System

  This system exists when organisms have:

  - A large surface area to volume ratio (simple diffusion cannot accommodate for the organisms)

  - A large activity of the organism (require more substances at one time than smaller organisms)
• Arteries

  Vessels that carry blood away from the heart and to arterioles at a high pressure. Most layers are thick so that they can function correctly and efficiently
• Arterioles

  Vessels that control blood flow from arteries to capillaries. Layers are thinner than arteries due to lower blood pressure
• Capillaries

  Tiny vessels that link arterioles to veins. These have branched networks to allow for a larger total surface area across the body, as they are so thin but have a vast network, no cell is too far away from one
• Veins


  Vessels that carry blood towards the heart from capillaries. Layers are very thin with a large lumen to ensure pressure is very low
• Fluid in Circulatory System

  These are all associated with the circulatory system:

  1) Blood

  2) Tissue fluid

  3) Lymph
• Tissue Fluid

  A fluid that allows cells to receive the contents of blood and utilise these products to stay alive and functioning. It is formed due to hydrostatic pressure and osmosis
• Capillary Network

  Where tissue fluid is formed
• Hydrostatic Pressure

  The pressure of the blood as the heart beats. This forces fluid and nutrients from the capillaries. A small amount of this pressure forces some fluid back into the network. But the net movement is out of the capillary network
• Osmotic Pressure

  The pressure that occurs due to sudden changes in water potential, moving water back into the capillary network via osmosis, where the water potential is lower