Cardiovascular Flashcards
A hollow, muscular organ located in the center of the thorax, where it occupies the space between the lungs and rests on the diaphragm
Heart
How much does the heart weigh?
300 g (10.6 oz)
The chambers of the heart become smaller as the blood is ejected
Systole (contraction of the muscle)
The heart chambers fill with blood in preparation for the subsequent ejection
Diastole (relaxation of the muscle)
Normal resting adult heart beat/rate
60- 80 bpm
On average, how much blood does each ventricle eject per beat?
70 mL per beat
How much blood does each ventricle eject per minute?
5 L per minute
Four major functions of the cardiovascular system
- To transport nutrients, gases, waste products
- To protect the body from infection and blood loss
- Thermoregulation
- To mainatain fluid balance
Three layers of the heart
Endocardium
Myocardium
Epicardium
The inner layer of the heart; consists of endothelial tissue and lines the inside of the heart and valves
Endocardium
The middle layer of the heart; made up of muscle fibers and responsible for the pumping action
Myocardium
Outer layer of the heart; visceral layer of the serous pericardium, made up of mesothelial cells
Epicardium
A thin, fibrous sac where the heart is enclosed
Pericardium
Two layers of the pericardium
Visceral and parietal
Layer of pericardium that is closest to the heart
Visceral pericardium
Layer of the pericardium that is a tough, fibrous tissue that attaches to the great vessels, diaphragm, sternum, and vertebral column and supports the heart in the mediastinum
Parietal pericardium
What are the 4 chambers of the heart
Right and left atrium
Right and left ventricle
2 chambers of the heart that distributes venous blood (deoxygenated blood) to the lungs via the pulmonary artery for oxygenation
Right atrium and right ventricle
Receives blood returning from the superior vena cava, inferior vena cava, and coronary sinus
Right atrium
2 chambers of the heart that distributes oxygenated blood to the remainder of the body via the aorta
Left atrium and left ventricle
Receives oxygenated blood from the pulmonary circulation via the pulmonary veins
Left atrium
What are the 2 types of valves?
Atrioventricular and semilunar
How many valves are there and what are those?
Four; Tricuspid valve, Bicuspid valve, Pulmonic valve, Aortic valve
The valves that separate the atria from the ventricles
Atrioventricular valves
Separates the right atrium from the right ventricle
Tricuspid valve
Lies between the left atrium and the left ventricle
Mitral/Bicuspid valve
Valve between the right ventricle and the pulmonary artery
Pulmonic valve
The valve between the left ventricle and the aorta
Aortic valve
Details about the cardiac muscle
Microscopically, myocardial muscles look like skeletal muscles, but it functions like a smooth muscle because its contraction is involuntary
The interconnected manner of arrangement of the myocardial muscle fibers
Syncytium
3 physiologic characteristics of the cardiac conduction cells
Automaticity
Conductivity
Excitability
Ability to initiate an electrical impulse
Automaticity
Ability to respond to an electrical impulse
Excitability
Ability to transmit an electrical impulse from one cell to another
Conductivity
The pacemaker of the heart
Sinoatrial node/ SA node
2 nodes of the heart
Sinoatrial and atrioventricular
The boundary between the right atrium and left ventricle, where the electrical signal cannot pass through
Atrioventricular septum
Specialized tissue which transmit the electrical charge to the heart muscle from the ventricles
Purkinje fibers
Explain the conduction system
SA node–AV node–Bundle of His–Right and Left bundle branch–Purkinje fibers
The blood circulates into the body’s systems, bringing oxygen to all it’s organs and collecting carbon dioxide
Systemic loop
The blood circulates to and from the lungs to release the carbon dioxide and pick up new oxygen
Pulmonary loop
Explain how the blood circulates
–
The amount of blood that is pumped by each ventricle per minute
Cardiac output
Degree of stretch of the cardiac muscle fibers at the end of the diastole
Preload
The period when filling volume in the ventricles is the highest and the degree of stretch is greatest
End of diastole
The stress in the wall of the left ventricle during ejection or the amount of resistance to ejection of blood to the ventricle
Afterload
Resistance of the systemic BP to left ventricular ejection
Systemic vascular resistance
The resistance of the pulmonary BP to right ventricular ejection
Pulmonary vascular resistance
The force generated by the contracting myocardium under any given condition, represents the innate ability of the heart muscle to contract
Contractility
TRUE OR FALSE. Contractility is enhanced by circulating catecholamine’s, sympathetic neuronal activity, and certain medications
TRUE
TRUE OR FALSE. Increased contractility results in increased stroke volume
TRUE
