Presentation on theme: "P5/ M2. The Heart Muscular pump, about the size of a clenched fist – Made up of a special muscle called Myocardium This can contract continuously without."— Presentation transcript:
The Heart Muscular pump, about the size of a clenched fist – Made up of a special muscle called Myocardium This can contract continuously without getting tired Main purpose is to drive blood through the arteries – This delivers blood to the working muscles and other tissues.
The Heart continued The Heart sits in a twin layered sac known as the Pericardium – Filled with pericardial fluid Prevents friction as your heart beats.
The Heart continued
Atria/ Atrium Upper chambers of the heart Receive blood. Right Atrium – receives deoxygenated blood from the body (Via the Vena Cava) Left Atrium – receives oxygenated blood from the lungs (Via the pulmonary Vein) Ventricles – Lower chambers of the heart – They have thicker walls and are stronger – Job is to pump the blood – Right Ventricle pumps blood to the lungs (pulmonary circulation) – Left ventricle pumps blood to the body (systemic circulation)
Valves Tricuspid Valve Bicuspid Valve – Also known as the mitral valve Aortic Valve Pulmonary Valve – All valves make sure that the blood flows in one direction, and there is no back flow Chordae Tendineae – Cord like tendons that connect to the tricuspid and bicuspid valves Ensure the valves stay the right way round and keep the blood flowing in the same direction.
Aorta and Vena Cava The largest Artery is the Aorta – Carries oxygenated blood directly out of the heart to the body tissues – Superior vena cava – brings blood from the upper body – Inferior Vena Cava – Brings blood from the lower body. The largest vein is the Vena Cava – Carries blood directly into the heart from the body
Pulmonary Circulation Pulmonary Artery – Carries deoxygenated blood from the heart to the lungs. It is the only artery that carries deoxygenated blood Pulmonary Vein – Carries oxygenated blood from the lungs to the heart It is the only vein that carries oxygenated blood.
The Heart = Double pump To describe the flow of blood around the heart and the body, you will need to mention that the heart is made up of two pumps – Pulmonary circulation Pumps blood to and from the lungs – Systemic circulation Pumps blood around the body
Passage of blood flow Blood flows into and out of the heart and around the body in one direction. The heart is split into two distinct pumps by the Septum. This makes sure that the oxygenated and deoxygenated blood don’t mix. When describing the passage of blood flow around the heart, it is best to use a diagram and start on the right side of the heart.
The right ventricle contracts and the blood is pushed out of the heart through the semi lunar or pulmonary valve and into the pulmonary artery The pulmonary artery carries the blood to the lungs The heart relaxes and the valves close to stop back flow of the blood In the lungs, the blood becomes oxygenated, and begins it’s journey back to the heart. Blood enters the heart (when it is relaxed) via the vena cavae, It goes into the right atrium The right atrium contracts and the blood goes through the tricuspid valve and into the right ventricle
The heart is relaxed, and this allows blood to enter the left side of the heart from the pulmonary vein It enters the left atrium The left atrium contracts and pushes blood through the bicuspid valve and into the left ventricle The left ventricle has a very strong muscular wall and contracts very strongly. This closes the bicuspid valve to prevent backflow, and pushes the blood through the aortic valve and into the aorta. This is the largest artery and splits taking the blood to different areas of the body The heart contracts and the aortic valve closes, preventing back flow of the blood.
Terminology Heart rate (H.R.) – The amount of times the heart beats in a minute. Usually measured in beats per minute (b.p.m.) Stroke Volume (S.V.) – The amount of blood leaving the left ventricle in one beat. Normally measure in mililitres Cardiac Output – The amount of blood leaving the heart in one minute Normally measured in litres/minute Cardiac Output = Stroke Volume x Heart Rate
The Blood Vessels Introduction We have a variety of different vessels within the cardiovascular system to deliver and remove nutrients and waste products. Blood in the arteries is bright red, as it is carrying oxygen. It drops off the oxygen and picks up carbon dioxide as it moves through the capillaries. By the time it reaches the veins and venules it is a much darker blue/red colour.
5 main blood vessels Arteries – Arterioles Capillaries – Venules Veins Carry blood away from the heart Where gas exchange takes place Carry blood back to the heart
Arteries & Arterioles Arteries are large blood vessels, that carry blood away from the heart. Carry Oxygenated blood – Apart from the pulmonary artery, which carries deoxygenated blood to the lungs to get Oxygen
Arteries & Arterioles Small round lumen Operate under high pressure Arteries don’t contain valves, as the blood is moving quickly under high pressure, so there is no chance of backflow. Aorta – Main artery leaving the heart It soon splits into smaller vessels – Arterioles – Arterioles deliver the blood to the capillaries
Capillaries Very thin walls – Allows oxygen and other nutrients to diffuse through the cell walls. Blood flows very slowly through the capillaries so that this can happen – Effectively in the capillaries, the blood unloads the Oxygen and picks up carbon dioxide and lactic acid (the waste products of metabolism) Smallest blood vessels – Found in all cells of the body Just one cell thick
Veins & Venules
Carry blood back to the heart – Generally working against gravity Particularly blood that is going back to the heart from the legs or arms, as it is below the heart. – Valves To prevent the blood from flowing back once the smooth muscle relaxes. Prevents pooling, particularly in the legs Deoxygenated blood – Apart from pulmonary vein which carries oxygenated blood from the lungs back to the heart.
Task… You are going to outline the function and characteristics of each of the 5 types of Blood Vessels that serve the circulatory system… Including: -Physical characteristics that classify each blood vessel. -What their function is within the CIRCULATORY system? -What do they transport? Followed by a description/ explanation of the composition of BLOOD
Blood It is the medium in which all the cells are carried to transport nutrients and Oxygen (O2) to the cells of the body. It carries: Oxygen, Glucose, Proteins, Fats, Vitamins, Hormones, Enzymes, Platelets, Carbon Dioxide and Electrolytes. - Oxygen, Glucose, Proteins, Fats, Vitamins, Hormones, Enzymes, Platelets, Carbon Dioxide and Electrolytes. Made up of 4 components: -Red blood cells -White blood cells -Platelets -Plasma Plasma Plasma: straw coloured liquid that all solids are carried within.
Red blood cells make up 99% of the population of the blood cells in the body They are RED in colour due to the presence of a protein called HAEMOGLOBIN and absolutely loves Oxygen (massive attraction!)
They are colourless and transparent and fewer in number to red blood cells (1:700) They destroy bacteria and other dangerous organisms… thus fighting potential infection.
They become sticky when in contact with air to form the initial stage of repair to the damaged tissue… They act by stopping blood loss through clotting Yet platelets need a substance called x-Factor 8 to enable them to become active and do their job/clot.
Describe the Structure and Function of the cardiovascular system Examine the cardiovascular system and explain how it works and how each part of the system is designed to meet its function Structure of the cardiovascular system (which you have to find pictures/ label and describe): Heart: Atria, Ventricles, Bicuspid valve, Tricuspid valve, Aortic valve, Pulmonary valve, Aorta, Vena cava – (superior and inferior), Pulmonary vein, Pulmonary artery Blood vessels: Arteries, Arterioles, Capillaries, Veins, Venuoles Function of the cardiovascular system: 1.Delivery of oxygen and nutrients 2.Removal of waste products 3.Thermoregulation (vasodilation and vasoconstriction of vessels); 4.Function of blood (oxygen transport, clotting, fighting infection)