Animal Transport

• The fluid involved in an open circulatory system is haemolymph
• When the heart contracts, haemolymph enters the body cavity and bathes tissues, when the heart relaxes it is sucked back into pores by negative pressure gradients
• the benefits of a double circulatory system are that blood can move faster around the body as it is pumped twice so doesnt lose speed at the lungs
• The tissues in capilliaries are a single thin layer of smooth endothelium
• Capillaries one cell thick and small for a short diffusion pathway and only one blood cell can travel through at a time slowing down blood flow for greater diffusion time
• Arteries have smooth muscle for contraction of artery, elastic fibres to stretch for accommodating pressure changes, collagen to prevent bursting, smooth endothelium for less friction
• Veins have a thin layer of elastin and muscle for stretch and contraction, smooth endothelium to reduce friction, collagen to prevent bursting, valves to prevent backflow
• Arterioles are narrower, arterioles have more muscle fibres for contraction, arterioles have less elastic tissue
• Venules are smaller, venules have no muscle fibres for vasodilation and vasoconstriction
• Capillaries have a large surface area with a capillary bed, very thin walls with small pores for permeability, there is a narrow lumen for slowed diffusion
• Myocardium is the cardiac tissue
• coronary arteries supply the heart
• The vena cava takes blood from the body to the right atrium
• The pulmonary artery takes blood to the lungs from the heart
• The pulmonary vein takes blood from the lungs to the left atrium
• The aorta takes blood to the body from the left ventricle
• The superior vena cava carries blood from the brain to the heart
• The inferior vena cava carries blood from the body to the heart
• The first stage of the heart beat is ventricular and atrial diastole
• In diastole, blood enters the atria passively from the vena cava and pulmonary vein, the atria and ventricles are both relaxed
• In atrial systole, the blood entering the atria puts pressure on the AV valves causing them to open, the atria will contract, decreasing their volume and increasing pressure, this forces blood into the ventricles
• Ventricular systole is when blood entering the ventricles causes a higher pressure in the ventricles than the atria, closing the AV valve, the ventricles contract, increasing pressure and decreasing volume, the pressure in the ventricles is higher than in the arteries so the semilunar valves open,
• COCO C - AV valves close O - semilunar valves open C - semilunar valves close O - AV valves open
• equation for cariac output is cardiac output = heart rate x volume of blood leaving left ventricle
• Tissue fluid includes glucose, amino acids, ions, oxygen, water, fatty acids
• The intercellular fluid involved in bathing tissues is called tissue fluid
• Tissues fluid formation starts at the arteriole end, there is a higher hydrostatic pressure than osmotic pressure, water containing glucose, amino acids and dissolved ions is forced out of the capilliary, this fluid bathes the tissues and glucose and ion uptake occurs, proteins remain in the capilliary reducing water potential, hydrostatic pressure is reduced toward the venule so osmotic pressure becomes greater by comparison, some water reenters the capilliary, the rest of the water returns to circulation via the lymphatic system
• A lymph node is a small sac containing white blood cell that traps pathogens
• Lymphatic vessels have valves
• Lymph fluids are transported by muscle contractions through the body
• The risk factors for cardiac disease include smoking, high blood cholesterol, diet, age, gender, race, family history
• Antioxidants prevent artery damage
• Higher pressure exerted on the arteries can cause damage and strain on the heart as it has to pump harder, arteries tend to thicken to withstand pressure
• A low density lipoprotein takes cholesterol from the liver to tissues causing damage
• A high density lipoprotein takes cholesterol from the tissues to the liver
• Haemoglobin is a globular protein with 4 peptide chains and 4 iron haem groups
• High oxygen affinity is where haemoglobin is likely to take up oxygen
• Low oxygen affinity is where haemoglobin is unlikely to take up oxygen
• After one oxygen binds to a haemoglobin forming oxyhaemoglobin, it is more likely for another oxygen to bind due to conformational shape change, however, the last oxygen to bind is difficult due to less available space on the protein
• Oxygen associates in the lungs