Mass transport and transport systems

• 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

  
• Bicuspid Valve

  The valve that separates the two chambers responsible for oxygenated blood

  
• Tricuspid Valve

  The valve that separates the two chambers responsible for deoxygenated blood

  
• 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)
• What does the Sinoatrial Nodedo?

  Release 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
• Pressure Gradient


  To allow for heart contraction, there needs to be one condition maintained within the heart at all times
• 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. This is blood pressure when the heart contracts.

  
• 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

  
• TP Interval


  The point on the graph which represents diastole - the "filling time" of the heart

  
• Blood Cholesterol

  Low density lipoproteins increase this in the arteries. These lipoproteins transport plaque from the liver to the tissues. High density lipoproteins reduce this as they do the opposite of low density lipoproteins
• Diet


  A factor increasing the risk of heart disease, if you have high saturated fats. The fats cannot be broken down so remain for a while which increases the likelihood of myocardial infarction
• Smoking


  A factor increasing the risk of heart disease. Carbon monoxide binds to red blood cells, which is irreversible for around 24 hours, which decreases the amount of oxygen getting to the heart, which can cause heart cells to die. Nicotine also increases heart rate and blood pressure
• High Blood Pressure

  A factor increasing the risk of heart disease. An increased heart rate increases the amount of adrenaline in the blood, making platelets more sticky and more likely to stick to artery wall, causing a blockage and hence myocardial infarction
• Thrombosis


  A blood clot
• 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