Cardiovascular Flashcards
Difference between veins and arteries
Arteries carry blood away from heart
Veins carry blood towards heart
What is the covering of the heart
Percardium: a double-walled sac
- Parietal pericardium is the outside layer that lines inner surface of fibrous pericardium
- Visceral pericardium is next to the heart, also known as the epicardium
Serous fluid fills the space between the parietal and visceral pericardium
Name and explain the 3 layers of the heart wall
Epicardium: outside layer made of connective tissue (visceral pericardium)
Myocardium: middle layer that mostly contains cardiac muscle
Endocardium: inner layer known as endothelium
What are the 4 chambers of the heart and what separates them
Left atrium, left ventricle, right atrium, right ventricle. Interventricular septum and interatrial septum
What are the 4 heart valves and their functions
AV Valves: bicuspid/mitral valve and tricuspid valve. They open during heart relaxation and close during ventricular contraction
Semilunar valves: aortic and pulmonary semilunar valves. They open during ventricular contraction and close during heart relaxation
What is the cycle of the pulmonary circulation
- Blood leaves the right ventricle
- Flows towards the pulmonary semilunar valve
- Flows towards the pulmonary trunk
- Flows to the left and right pulmonary arteries
- Flows to the respiratory capillaries (alveoli) where gas exchange takes place
- Flows to the right and left pulmonary veins
- Flows into left atrium
Cycle of systemic circulation
- Blood leaves the left ventricle
- Flows into the aortic semilunar valve
- Flows into the ascending aorta and aortic arch
- Flows into the arteries
- Flows into the numerous branches and capillary beds in the tissues
- Flows into the systemic veins
- Flows into the superior and inferior venae cavae and coronary sinus
- Flows back into the right atrium
What is the operation of the AV valves
- Blood returning to the atria puts pressure against the AV valves, forcing it open
- As ventricles fill, AV valves hang limply into the ventricles as the atria contracts, forcing additional blood into the ventricles
- Ventricles contract, forcing blood against AV valve flaps, making it close.
- Chordae tendinae tighten, preventing the AV valves from everting into the atria.
What is the operation of semilunar valves
- As ventricles contract, intraventricular pressure increases, and blood is pushed up against the aortic and pulmonary semilunar valves, and they are forced open.
- As ventricles relax, intraventricular pressure decreases, and blood flows back from the arteries, filling the leaflets of the semilunar valves, forcing them to close.
What are the components and functions of the coronary circulation?
Coronary arteries branch from the aorta to supply the heart muscle with oxygenated blood
Coronary veins drain the myocardium of blood
Coronary sinus is a large vein on the posterior of the heart that receives blood from the cardiac veins
Blood empties into the right atrium via coronary sinus
State the components of the conducting system of the heart
Sinoatrial node
Atrioventricular node
AV Bundle
Bundle branches
Purkinje fibres
Name all the blood vessels that supply blood to the heart muscles
Left and right coronary artery
Anterior interventricular artery
Posterior interventricular artery
Left and right marginal arrtery
Left circumflex artery
Explain the stimulus of contraction by the conduction system
SA node starts the heartbeat as impulse spreads to the AV node and atria contract.
At the AV node, impulse passes through AV bundle, bundle branches, and Purkinje fibers.
Blood is ejected from ventricles to aorta and pulmonary trunk as ventricles contract
What are the different waves of the heart rhythm?
P wave - depolarisation (atrial contraction, generated at SA node)
QRS wave - depolarisation (represents ventricular contraction)
T wave - represents ventricular relaxation (repolarisation)
What is cardiac output and the formula?
Cardiac output is the amount of blood pumped by each ventricle in one minute.
CO(ml/L per min) = HR x SV
Stroke Volume (SV) = EDV - ESV
