Transport in Humans

• The circulatory system is a network of blood vessels that carries blood throughout the body

  
• The heart is the main organ of the circulatory system, pumping blood through the blood vessels
• Arteries carry blood away from the heart, while veins carry blood back to the heart
• Capillaries are small blood vessels that connect the arteries to the veins, allowing for the exchange of nutrients and waste products between the blood and the surrounding tissues
• In the human circulatory system, red arrows indicate oxygenated blood flowing from the lungs to the heart and then to the rest of the body, while blue arrows indicate deoxygenated blood flowing from the body to the heart and then to the lungs

  
• A diagram of a human heart shows the four chambers, valves that control blood flow, and major blood vessels entering and leaving the heart

  
• The cardiac cycle is the sequence of events during one heartbeat, starting with atrial muscles contracting to push blood into the ventricles, followed by ventricles contracting to pump blood out of the heart and into the body

  
• A diagram of the aortic valve opening and blood being forced out of the heart and into the aorta

  
• The circulatory system consists of the heart and blood vessels that circulate blood around the body, transporting nutrients, oxygen, hormones, fighting diseases, and removing waste products
• The structures of the heart and its associated blood vessels facilitate the transport of blood around the body
• The structure of red blood cells enables the efficient transport of oxygen around the body
• Components of blood include red blood cells, plasma, white blood cells, and platelets, each with specific roles in transport and defense
• Red blood cells contain haemoglobin for oxygen transport, plasma transports various substances, white blood cells perform phagocytosis and antibody formation, while platelets help in blood clotting
• The heart functions through muscular contraction and the working of valves
• Coronary heart disease involves the occlusion of coronary arteries, with possible causes like an unhealthy diet, sedentary lifestyle, and smoking; preventative measures include lifestyle changes and medication
• Arteries have thick, muscular, and elastic walls to withstand high blood pressure, while veins have less muscle and elasticity, relying on skeletal muscle contractions to move blood along
• Capillaries are microscopic blood vessels found between tissue cells, allowing for the exchange of substances between blood and tissues
• Capillary walls are partially permeable, facilitating the exchange of nutrients and waste products between blood and tissues
• Substances are exchanged between capillaries and tissue fluid through diffusion, allowing for the movement of oxygen and nutrients into cells
• The circulatory system is essential for transporting substances, fighting diseases, and removing waste products in the body
• The human circulatory system is also known as the transport system, consisting of blood, blood vessels, and the heart
• The circulatory system includes two pathways of circulation: pulmonary circulation and systemic circulation
• The circulatory system is crucial for providing nourishment to cells, fighting diseases, and removing waste products from the body
• The circulatory system is vital for transporting oxygen, nutrients, and hormones around the body
• The circulatory system is essential for the efficient transport of substances from one part of the body to another, which simple diffusion cannot achieve
• The circulatory system is made up of blood, blood vessels, and the heart, working together to circulate blood and transport substances throughout the body
• The circulatory system is crucial for the exchange of nutrients and waste products between the blood and surrounding tissues
• The human circulatory system is a network of blood vessels that carries blood throughout the body

  
• Arteries carry blood away from the heart, veins carry blood back to the heart, and capillaries connect arteries to veins

  
• Capillaries are the smallest blood vessels, consisting of a single layer of endothelial cells, allowing for the exchange of nutrients and waste products between blood and tissues

  
• In the human circulatory system, red arrows indicate oxygenated blood flowing from the lungs to the heart and then to the body, while blue arrows show deoxygenated blood flowing from the body to the heart and then to the lungs

  
• The human heart has four chambers: two atria and two ventricles

  
• The atria receive blood from veins and have thinner walls than ventricles, while ventricles have thick muscular walls
• The left ventricle is thicker than the right to exert high pressure to pump blood around the body
• The heart's median septum separates the right and left sides, preventing the mixing of deoxygenated and oxygenated blood
• Valves in the heart, like tricuspid and bicuspid valves, prevent backflow of blood between chambers
• Blood flow through the heart: deoxygenated blood returns to the right atrium, passes through the tricuspid valve to the right ventricle, then to the lungs via pulmonary arteries
• The cardiac cycle is the sequence of events in one heartbeat, involving atrial and ventricular muscle contractions and relaxation, and valve openings and closings
• Coronary heart disease involves the occlusion of coronary arteries due to fatty deposits, leading to heart muscle damage and potential heart attacks
• Risk factors for heart disease include smoking, unhealthy diet, sedentary lifestyle, genetic factors, age, stress, and gender