Circulatory System CIRCULATORY SYSTEM The circulatory system is a network consisting of blood, blood vessels, and the heart. This network supplies tissues in the body with oxygen and other nutrients, transports hormones, and removes unnecessary waste products. FUNCTIONS ● Helps the body maintain a normal body temperature ● Fights off disease ● Provides the right chemical balance to provide the body’s homeostasis, or state of balance, among all its systems Oxygen enters the bloodstream through tiny membranes in the lungs that absorb oxygen as it is inhaled. AMAZING FACTS ABOUT THE CIRCULATORY SYSTEM ● ● ● Capillaries are quite tiny and are about 8 microns in diameter, and quite interestingly, red blood cells are almost of the same size as the capillaries. Other cells in your body have nuclei, but your red blood cells are different, because they contain no nuclei and that's why they can carry more oxygen. There is no such thing as A "broken heart" after an emotional setback. This experience is known as "broken heart syndrome" which is characterized by a sudden, temporary weakening of the muscle of your heart. Main Circulatory System Organs 1.The Heart ● It is made of specialized cardiac muscle tissue that allows it to act as a pump within the circulatory system ● It is divided into four chambers wherein it is composed of 2 auricles (top chambers which receives blood from the veins) and 2 ventricles (bottom chambers which pump blood into arteries). Main Circulatory System Organs 1.The Heart ● As blood leaves each chamber of the heart, it passes through valves guarded by flaps or cusps. ● Four heart valves, namely the mitral valve, tricuspid valve, aortic valve, and pulmonary valve, work to prevent blood from flowing in the wrong direction. ● The valves open in one direction like trapdoors to let blood pass through. Then they close, so blood cannot flow backwards into auricles. Aorta ● The largest artery in the body ● It begins at the top of the left ventricle, the heart’s muscular pumping chamber. ● The heart pumps blood from the left ventricle into the aorta through the aortic valve. ● Three leaflets on the aortic valve open and close with each heartbeat to allow one-way flow of blood. Pulmonary Trunk ● ● ● A major vessel of the human heart that originates from the right ventricle. It branches into right and left pulmonary arteries which leads to the lungs. The function of these vessels is to transmit oxygendepleted, carbon dioxide-rich blood from the right ventricle to the lungs. Superior Vena Cava ● The superior of two venae cavae, the great venous trunks that return deoxygenated blood from the systemic circulation to the right atrium of the heart. ● It is a vein that is short and has a large diameter (24mm) that receives venous return from the upper half of the body, above the diaphragm ● It is located in the anterior right superior mediastinum Inferior Vena Cava ● It is also known as the posterior vena cava ● It is a large diameter vein that is located posterior to the abdominal cavity and runs along the right side (thus making it a retroperitoneal structure), with the aorta lying laterally on the left of the IVC. ● It is the result of two major leg veins coming together. The iliac veins come together at the small of the back, at the fifth lumbar vertebra. Once the iliac veins have merged, the inferior vena cava begins to transport blood to the heart. Atrium ● ● ● It is the upper chamber through which blood enters the heart. It receives blood, and when the heart muscle contracts they pump blood to the ventricles. There are two atria in the human heart – the left atrium connected to the lungs, and the right atrium connected to the venous circulation. Ventricle ● ● ● It is one of two large chambers toward the bottom of the heart that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. Right ventricle: Receives blood from the right atrium and pumps it to the main pulmonary artery. Left ventricle: Receives blood from the left atrium and pumps it to the aorta. Blood returning to the heart from the lungs enters the left atrium and passes through the mitral valve to the left ventricle. Pulmonary Veins ● ● ● ● It is responsible for carrying oxygenated blood from the lungs back to the left atrium of the heart. This differentiates the pulmonary veins from other veins in the body, which are used to carry deoxygenated blood from the rest of the body back to the heart. Humans have four pulmonary veins in total, two from each lung. Each pulmonary vein is linked to a network of capillaries (small blood vessels) in the alveoli of each lung. COMMON MISCONCEPTIONS Arteries carry oxygenated blood and veins carry deoxygenated blood. Pulmonary veins carry oxygenated blood towards the heart and the pulmonary arteries carry deoxygenated blood away from the heart. Blood is always red. Veins can appear blue as we see them through our skin, leading some people to believe that deoxygenated blood is blue. However, Blood only appears blue because of the way tissues absorb light and our eyes see color. Although oxygen does have an effect on the brightness of the blood (more oxygen makes a brighter red, less makes it darker), blood is never actually blue. Main Circulatory System Organs 2. The Blood and the Blood Vessels ● Blood from the heart is pumped throughout the body using blood vessels. ● Blood vessels allow blood to flow quickly from one region to another and then allows it to come back to your heart. ● Blood vessels have a hollow area that allows for easy flow of blood and it's called lumen. Red Blood Cells These cells take oxygen from your lungs and transport it to the rest of your body cells. After delivering the oxygen, it gathers up the carbon dioxide and delivers it back to your lungs. White Blood Cells These blood cells play a role in fighting off germs and protect you from diseases. Your body produces more white blood cells to deal with an infection in your body. Platelets When you cut yourself, platelets start accumulating at the opening and plug up the hole brought about by a wound to stop bleeding. Once platelets start sticking to the opening of a damaged blood vessel, they start attracting more fibers, platelets and other blood cells to prevent excessive bleeding. Plasma The plasma transports your blood cells, nutrients, hormones, and many other components throughout your body Three Basic Types of Blood Vessels ● Arteries take oxygen-rich blood away from your heart. ● Veins take blood back toward your heart. ● Capillaries are very tiny blood vessels that form a connection between arteries and veins. The capillary walls facilitate the transfer of oxygen, nutrients and wastes in and out of your body. The Lungs ● The lungs provide oxygen for the body. ● It sends oxygen-rich blood to the left side of your heart and your heart then uses blood vessels and arteries to transfer it to the rest of your body. CIRCULATIONS The human circulatory system consists of 3 major circuits: ● The pulmonary circuit provides blood flow between the heart and lungs. ● The systemic circuit allows blood to flow to and from the rest of the body. ● The coronary circuit provides blood to the heart. strictly Pulmonary Circulation It carries deoxygenated blood away from the right ventricle of the heart, to the lungs and returns oxygenated blood to the left atrium and ventricles of the heart. Systemic Circulation The systemic circulation provides the functional blood supply to all body tissue. It carries oxygen and nutrients to the cells and picks up carbon dioxide and waste products. Systemic circulation carries oxygenated blood from the left ventricle, through the arteries, to the capillaries in the tissues of the body. From the tissue capillaries, the deoxygenated blood returns through a system of veins to the right atrium of the heart. Coronary Circulation It supplies blood to and provides drainage from the tissue of the heart. Deoxygenated blood is returned to the chambers of the heart via coronary veins. DISEASES OF THE CIRCULATORY SYSTEM Arteriosclerosis ● A general term for hardening and suffering of arteries and arterioles. ● The fatty deposits in the arteries causes the walls to stiffen and it increases the blood pressure when the arteries of the kidney are partially or completely blocked and thicken the walls. Hypertension Commonly called “high blood pressure” It causes the heart to work harder which leads to such complications: ● Stroke ● Kidney Failure ● Heart Stroke Aortic Aneurysm It occurs when the aorta is damaged and start to bulge or tear. Causes: ● Severe internal bleeding ● Obesity ● High blood pressure Peripheral Arterial Disease (PAD) ➔ It involves areas of narrowing or blockage within an artery. ➔ It has narrowed arteries that reduce blood flow to the limbs. ➔ It build up fatty deposits in the arteries ➔ It restricts blood supply to legs KEY TERMS: A SUMMARY Cardiac - related to the heart Pulmonary - related to the lungs Artery - a blood vessel that moves blood away from the heart Vein - a blood vessel that moves blood toward the heart Aorta - major artery that carries blood to the systemic circulatory system Capillary - small blood vessel that allows nutrient exchange Atrium - upper chamber of the heart Ventricle - lower chamber of the heart 3 Types of Circulation 1. 2. 3. Matching Type 4. Take oxygen-rich blood away from your heart. 5. Take blood back toward your heart. 6. Are very tiny blood vessels that form a connection between arteries and veins. 7. It prevents excessive bleeding. Choices: Red Blood Cells, Capillaries, Arteries, Ventricle, Plasma, White Blood Cells, Veins, Platelets Matching Type 8. It transports your blood cells, nutrients, hormones, and many other components throughout your body. 9. These cells take oxygen from your lungs and transport it to the rest of your body cells. 10. These blood cells play a role in fighting off germs and protect you from diseases. Choices: Red Blood Cells, Capillaries, Arteries, Ventricle, Plasma, White Blood Cells, Veins, Platelets TRUE or FALSE 11. The circulatory system is a network consisting of blood, blood vessels, and the heart. 12. Pulmonary Trunk is the major vessel of the human heart that originates from the left ventricle. 13. Atrium is the lower chamber through which blood enters the heart. 14. Pulmonary Veins is responsible for carrying deoxygenated blood from the lungs back to the left atrium of the heart. 15. Aorta is the largest artery in the body. 16.Oxygen enters the bloodstream through tiny membranes in the lungs that absorb oxygen as it is inhaled. 17. It is made of specialized cardiac muscle tissue that allows it to act as a pump within the circulatory system. 18. Blood vessels have a hollow area that allows for easy flow of blood and it's called lumen. 19. Peripheral Arterial Disease occurs when the arterial is damaged and start to bulge or tear. 20. Aortis Aneurysm cause the heart to work harder which leads to such comlications like Stroke. ANSWER KEY 3 Types of Circulation 1. Coronary Circulation 2. Pulmonary Circulation 3. Systemic Circulation 4. Take oxygen-rich blood away from your heart. Arteries 5. Take blood back toward your heart. Veins 6. Are very tiny blood vessels that form a connection between arteries and veins. Capillaries 7. It prevents excessive bleeding. Platelets 8. It transports your blood cells, nutrients, hormones, and many other components throughout your body. Plasma 9. These cells take oxygen from your lungs and transport it to the rest of your body cells. Red Blood Cells 10. These blood cells play a role in fighting off germs and protect you from diseases. White Blood Cells 11. The circulatory system is a network consisting of blood, blood vessels, and the heart. TRUE 12. Pulmonary Trunk is the major vessel of the human heart that originates from the left (right) ventricle. FALSE 13. Atrium is the lower (upper) chamber through which blood enters the heart. FALSE 14. Pulmonary Veins is responsible for carrying deoxygenated (oxygenated) blood from the lungs back to the left atrium of the heart. FALSE 15. Aorta is the largest artery in the body. TRUE 16.Oxygen enters the bloodstream through tiny membranes in the lungs that absorb oxygen as it is inhaled. TRUE 17. It is made of specialized cardiac muscle tissue that allows it to act as a pump within the circulatory system. TRUE 18. Blood vessels have a hollow area that allows for easy flow of blood and it's called lumen. TRUE 19. Peripheral Arterial Disease (Aortic Aneurysm) occurs when the arterial is damaged and start to bulge or tear. FALSE 20. Aortis Aneurysm (Hypertension) cause the heart to work harder which leads to such comlications like Stroke. FALSE References: https://www.healthline.com/human-body-maps/circulatory-system#1 https://biologydictionary.net/circulatory-system/ https://www.wisegeek.com/what-are-the-parts-of-the-circulatory-system.htm https://www.khanacademy.org/science/high-school-biology https://www.kenhub.com/ https://www.livescience.com/22486-circulatorysystem.html?fbclid=IwAR2_VuyIjWMrUlSYZVkqjV41W9MYXcRl2b4iRu50JpRXpwy0UNUIQ6b9Vg4