Circulatory system

• what is the circulatory system?

  a network of organs and vessels which enables the flow of blood and transport of oxygen, carbon dioxide, nutrients and other molecules around the body.
• blood?


  body fluid which serves as a transport medium for nutrients and molecules around the body.
• four main components of blood?

  • red blood cells, white blood cells, plasma, platelets
• function - red blood cells?

  • Transport oxygen from the lungs to tissues
• white blood cells - function?

  • Phagocytes engulf and destroy pathogens ● Lymphocytes produce antibodies
• plasma - function?

  • Pale-yellow liquid portion of the blood that transports proteins, nutrients, waste products, hormones, antibodies, etc.
• function - platelets?

  • role in blood clotting
• how are red blood cells adapted to their function?

  Biconcave disk gives a large surface-area-to-volume ratio, Small and flexible
• how are phagocytes adapted to their function?

  • Can change shape, Flexible membrane, Contain enzymes that digest pathogens
• double circulatory system?


  Mammals have a double circulatory system where blood flows through the heart in two circuits: pulmonary circuit and systemic circuit.
• pulmonary circuit?

  • Involves right side of heart, Deoxygenated blood transported to lungs, Gaseous exchange occurs between alveoli and capillaries, Oxygenated blood returns to left side of heart
• systemic system?

  • Involves left side of heart, Oxygenated blood pumped to tissues and organs around body, Exchange of materials occurs at tissues, Deoxygenated blood returns to right side of heart
• structure of heart?

  • a muscular pump that pushes blood around the body. It consists of four chambers (left atrium, left ventricle, right atrium and right ventricle) and associated blood vessels.
• structure of heart

  here is

  
• The blood flow of the heart?

  • Pulmonary vein → Left atrium → Left ventricle → Aorta → Body → Vena cava → Right atrium → Right ventricle → Pulmonary artery → Lungs
• what are valves?

  • Valves prevent backflow of blood. They ensure that blood flow occurs in one direction only
• what are the 2 types of valves?

  • semilunar & Atrioventricular
• Atrioventricular - bicuspid/tricuspid location of valve?

  bicuspid - Between left atrium and left ventricle & tricuspid - Between right atrium and right ventricle
• function of bicuspid/tricuspid valve?

  • stop blood flowing backwards from the ventricles into the atria
• location of semilunar valve?

  • between ventricles and arteries
• Function of semilunar valves?

  • Ensure that after leaving the heart, blood is not drawn back into the ventricles
• what are the 3 types of blood vessels?

  arteries, veins, and capillaries
• Arteries?

  • carry blood away from the heart under high pressure
• veins?

  • carry blood towards the heart under low pressure
• capillaries?

  • enable the exchange of materials at tissues
• function of artery?

  • Narrow lumen maintains high pressure, thick wall, thick layer of smooth muscle, thick layer of elastic fibre, smooth inner lining
• function of vein?
• function of vein?

  • large lumen, thin wall, valves prevent backflow of blood, thin layer of smooth muscle & elastic fibre
• function capillary?

  • large network, one cell thick, walls permeable, narrow lumen
• cardiovascular disease?


  Cardiovascular disease is a group of diseases affecting the heart or blood vessels
• what can lead to heart attack & strokes?

  A build up of fatty deposits on the walls of the arteries. reduce blood flow to muscle tissue. Blood clots may form, blocking the arteries and stopping blood flow completely.
• risk factors of CVD?

  high blood pressure, smoking, obesity, lack of exercise, poor diet
• three methods for treating CVD?

  Improving diet and lifestyle, Medication, Angioplasty