The cardiovascular system, diabetes and obesity

Overview This topic looks at the structure and function of the cardiovascular system with an emphasis on diabetes, obesity and their effects on the system. There are 4 areas of study The structure and function of arteries, capillaries and veins The structure and function of the heart The pathology of cardiovascular disease Blood glucose levels and obesity

The structure and function of arteries, capillaries and veins What do you know already? Label the diagrams provided and write any notes What you need to know? Structure of all 3 types of blood vessel Flow of blood in the vessels including pressure changes The exchange of materials between blood vessels and tissues How the lymph system works with the circulation

Overview

Overview

Overview Heart pumps blood 2 circulations (lungs/body) Arteries Capillaries Veins Blood variety of reds Diagrams Oxygenated blood (red) Diagrams Deoxygenated blood (blue) Diagrams arteries red except pulmonary artery Diagrams veins blue except pulmonary vein Arteries blood away from heart Veins blood towards the heart Arteries>arterioles>capillaries>venules>veins Pressure changes from high to low

Arteries

Arteries Outer layer of connective tissue with elastic fibres Middle layer with smooth muscle and elastic fibres Inner lining is the endothelium Lumen (channel) is relatively narrow Elastic walls stretch and recoil with surge of blood Smooth circular muscle can contract (vasoconstriction) Smooth circular muscle can relax (vasodilation) Blood flow can be controlled Pressure higher than capillaries and veins

Capillaries Link arteries to vein Allow exchange of substances with tissues Endothelium 1 cell thick Close to all cells O2, dissolved food, ions CO2, metabolic waste

Tissue fluid Fluid is squeezed out of the blood from capillaries Difference in pressure between capillary and tissue cells causes fluid to leave capillaries (plasma) Tissue fluid contains glucose, amino acids, respiratory gases and ions Tissue fluid contains very little or no protein, it is too big to be passed out of the capillaries

Veins

Veins Outer layer of connective tissue with elastic fibres Middle layer with smooth muscle Elastic fibres and muscle wall much thinner than arteries Not very elastic Wider lumen (channel) than arteries Lower pressure than arteries Valves prevent backflow of blood Surrounding muscle tissue helps move blood by contractions Pressure lower than capillaries and arteries

Lymphatic system and circulation Some excess fluid enters the lymphatic vessels Lymph fluid is moved by muscles compressing lymph vessels Lymph fluid is returned to veins in the arms via lymphatic ducts

What do you know? What are the 3 types of blood vessel? Describe them (diagram and label) Describe their function and relate to structure Describe and explain pressure changes in system What is vasoconstriction? What is vasodilation? Why do veins have valves? What is tissue fluid? What is lymph? What does the lymphatic system do?