click below
click below
Normal Size Small Size show me how
Heart+Circulation
Question | Answer |
---|---|
What is the definition of the heart? | The pump that generates blood flow around the system. |
What is the definition of the arterial system? | The conductance vessels that carry the blood around the body. |
What is the definition of microcirculation? | Where transfer of nutrients, waste and water occurs. |
What is the definition of the venous system? | The capacity vessels, that store and return blood to the heart. |
Where is the heart located? | Lies centrally in the chest, between the lungs and pleura, in the middle mediastinum. |
What is the heart surrounded by? | The pericardial sac of fibrous tissue, that is lined by a serous, slippery membrane that secretes a miniscule amount of lubricating fluid. |
Describe the chambering system of the heart. | The heart has 4 chambers that contract in synchrony, as a single unit or syncytium to pump blood. |
The heart must be muscular, but... | ...be able to transmit waves of conduction and contraction. |
It must beat continually... | ...at variable rates, from slow to fast, but never tire. |
How is blood flow direction controlled? | Blood flow must only flow in one direction and is controlled by valves. |
What is the ideal space for the heart? | It must lie within a lubricated, potential space to allow expansion and contraction. |
Define auricle. | A small pouch in the wall of each atrium of the heart. |
What is the bottom surface of the heart called? | Diaphragmatic surface. |
What is the anterior surface of the heart called? | Sternocostal. |
What forms the inferior diaphragmatic surface? | The left ventricle. |
What does the left atrium form and where does it lie? | It forms the base of the heart and lies posteriorly. |
What is the circulatory system of the BODY called? | The systemic circulation. |
Where in the heart does blood return to from the systemic system? | The right atrium. |
Which valve links the right atrium to the right ventricle? | The tricuspid valve. |
Where does the right ventricle pump blood to? | The pulmonary trunk. |
What does the pulmonary trunk divide into? | The left and right pulmonary arteries. |
What is the process of making deoxygenated blood oxygenated called? | Pulmonary circulation. |
What does oxygenated blood return to the left atrium in? | The left and right, superior and inferior pulmonary veins. |
Which valve connects the left atrium to the left ventricle? | The mitral valve. |
What does the left ventricle pump blood into? | The aorta, which "conducts" it into the body (systemic circulation). |
How many litres of blood are there in the body? | 5 litres. |
What are all blood cells lined by? | Endothelial cells. |
What takes blood into the right atrium? | Superior vena cava, Inferior vena cava and Coronary sinus. |
What takes blood out of the right atrium? | The tricuspid valve. |
What is the coronary sinus? | A collection of veins joined together to form a large vessel that collects blood from the heart muscle (myocardium). |
What is the fossa ovalis? | The site of what was the foramen ovale in the embryo. |
What is the foramen ovale? | An opening from right to the left atrium that allowed oxygenated blood coming from the mother to by-pass the non-functioning foetal lungs. |
What forms the cardiac conduction system? | The sinoatrial and atrioventricular node. |
What does the left atrium receive blood from? | The 4 pulmonary veins that bring oxygenated blood from the lungs. The superior and inferior, left and right pulmonary veins. |
What is the function of the papillary muscles? | They send tendinous cords to the edges of the valve cusps. |
What opens and closes the tricuspid and mitral valves? | The pressure of the blood. |
What does LAB RAT stand for? | Left atrium bicuspid, Right atrium tricuspid. |
What do the papillary muscles and tendinous cords prevent? | Cusp eversion into the atrium during ventricular contraction. |
What happens to the surface of the ventricle walls near the outflow? | It becomes smooth to create laminar blood flow into the pulmonary trunk and aorta. |
What type of cusps do the pulmonary and aortic valves have? | Semilunar "watch-pocket" cusps. |
What happens to the cusps during systole? | Blood passes through the valve, forcing the cusps against the vessel wall. |
What happens to the cusps during diastole? | Elastic recoil in the pulmonary trunk and aorta forces blood between the cusps and the vessel wall forcing the cusps to meet in the centre of each vessel. |
Where do the left and right coronary arteries arise from? | The aortic sinuses just above the valve cusps. |
What is the function of the sinoatrial node? | (The pacemaker) can be sped up or slowed down by the autonomic nervous system. |
After it leaves the SAN, where does the wave of conduction pass to? | The atrioventricular node. |
What is the only route by which conduction may pass after it leaves the AVN? | The bundle of His. |
What happens to the wave of conduction after reaching the Bundle of His? | It continues into the left and right bundle branches that spread the conduction through each ventricle. |
What does the coronary conductive system ensure. | Synchronous contraction, in the correct sequence, toward the outflow of each chamber. |