Soc15: The Structure of the Heart Flashcards
Vasodilation
When veins swell up or dilate; widening of the internal diameter (lumen) of the blood vessel to allow increased blood flow.
Vasoconstriction
when veins shrink down; narrowing of the internal diameter of the blood vessel to decrease blood flow.
What are the 3 main three functions of the cardiovascular system?
Transports oxygen, carbon dioxide and nutrients. It helps clot blood. It controls the bodys temperature.
Cardio-respiratory system
The interaction of the heart and lungs to supply oxygen to muscles during exercise.
Vascular shunting
Your muscles need more blood for movement and so move away from the organs to the muscles. Your heart starts to beat faster and your blood vessels constrict into order to divert the blood to the muscles. Your reflexes get faster and your muscles may tense up.
The 4 characteristics of Arteries
Arteries take blood away from the heart Arteries have thick walls and are more elastic than veins as they carry blood which is at a higher pressure than veins as they carry oxygenated blood. The channel the blood flows through, called the lumen, can widen to allow more blood through when you so that it can reach the working muscles. The pulmonary artery is different from other arteries as it carries deoxygenated blood from the heart to the lungs
The 4 characteristics of Veins
Veins carry blood into the heart. Veins have much thinner walls, are less elastic and carry blood at a lower pressure. Veins contain many valves which helps deoxygenated blood flow to the heart. The pulmonary vein is different to other veins as it carries oxygenated blood from the lungs back to the heart.
The 4 characteristics of Capillaries
Capillaries are microscopic vessels - just one cell thick. At one end, capillaries carry oxygenated blood which transfers oxygen and nutrients to the muscles. At the other end, they carry deoxygenated blood into the veins, picking up waste products and taking them around the body to dispose of them. Capillaries are where gaseous exchange takes place
What is the role of the pulmonary vein?
The pulmonary vein takes oxygenated blood from the lungs to the left atrium
What is the role of the pulmonary artery?
The pulmonary artery takes deoxygenated blood from the right ventricle to the lungs
What is the role of the Vena Cava?
The Vena Cava allows deoxygenated blood into the right atrium
What is the role of Aorta?
The Aorta allows oxygenated blood from the left ventricle around the body
Red blood cells
Red blood cells transport oxygen from the lungs to the body cell, and carbon dioxide from the cells to the lungs. They contain haemoglobin which stores carbon dioxide and oxygen.
Platelets
Blood platelets are formed in the bone marrow Tiny fragments that clump together to help blood clot and stop bleeding Blood is the first line of defence in the repair of a wound When a blood vessel is out, platelets rush to the area and swell into irregular shapes, they become sticky and act as a plug
Plasma
The main role of plasma is to take nutrients hormones and proteins to the parts of the body that need it. Cells also put their waste products into the plasma. The plasma then helps remove this waste from the body.
