Cardiology Lecture 1 Flashcards
Components of the Cardiovascular System
- blood (fluid)
- blood vessels (pipes or container)
- heart (pump)
Components of Blood
- 45% red blood cells (erythrocytes): hemoglobin and oxygen
- plateletes (thrombocytes): clotting
- white blood cells (leukocytes): monocytes, basophils, eosinophils, neutrophils
- 54% plasma: transport medium
Blood Volume for an Adult
average 4-6 liters for an adult
Perfusion
flow of oxygenated blood throughout the body and to the cells
Blood Distribution at Any Given Moment
- 30% of the blood in your systemic circulation will be found in the arteries
- 5% in the capillaries
- 65% in the vein
Arteries
carry blood from the heart to all body tissues
Arterioles
smallest branches of arteries leading to the vast network of capillaries
Coronary Arteries
blood vessels that carry blood and nutrients to the heart
Veins
carry blood from the tissues to the heart
Venules
smallest branches of veins leading to the vast network of capillaries
Superior vena cava
carries blood returning from the head, neck, shoulders, and upper extremities
Inferior vena cava
carries blood returning from he abdoment, pelvis, and lower extremities
Valves
prevent backflow
* when AV valves open, semulinar valves close
* when semilunar valves open, AV valves close
Semilunar valves
located at the right and left ventricle
* aortic valve
* pulmonic valve
Artioventricular (AV) valves:
located at the right and left atrium
* mitral valve (bicuspid)
* tricuspid valve
Capillaries
small blood vessels that connect arterioles and venules; various substances pass through capillary walls, into and out of interstitial fluid, and then on to the cells
Diastole
the relaxation, or period of relaxation, of the heart, especially the ventricles
Systole
the contraction, or period of contraction of the heart, especially that of ventricles
Circumflex artery
one of two branches of your left main coronary artery that delivers oxygenated blood to the back and side of the heart’s left chambers
Left anterior descending artery
largest coronary artery that delivers oxygenated blood to the front of the heart’s left chambers
Left coronary artery
supplies blood to the left side of the heart muscle
Right coronary artery
supplies blood to the right side of the heart muscle
Preload
volume of blood in ventricles at end of diastole (end diastolic pressure)
Increase in Preload
- hypervolemia
- regurgitation of cardiac valves
- heart failure
Afterload
resistance left ventricle must overcome to circulate blood
Increased in afterload
- hypertension
- vasoconstriction
Parasympathetic
decreases heart rate, relaxes heart
Sympathetic
increases heart rate, induces heart
Automaticity
cells can contract without nerve impulses, the heart itself can conduct
Baroreceptors
receptors that detect pressure
Sinoatrial (SA) node
inherent rate of 60-100/min
Atrioventrikular (AV) node
inherent rate of 40-60/min
Purkinje fibers
inherent rate of 20-40/min
Stroke volume
amount of blood ejected by the heart in one cardiac cycle (50-100 mL)
Cardiac output (CO)
amount of blood pumped by the heart in one minute (stroke volume X heart rate)
Peripheral vascular resistance (PVR)
resistance to blood flow due to the peripheral blood vessels (blood pressure = cardiac output X peripheral vascular resistance)
Dysrythmia
inadequate heart rate
Tachycardia
fast heart rate
Bradychardia
slow heart rate
Atherosclerosis
cholesterol and calcium build up inside the walls of the blood vessels, forming plaque, which eventually leads to a partial or complete blockage of flow
Ischemia
a lack of oxygen that deprives tissues of necessary nutrients, resulting from partial or complete blockage of blood flow; potentially reversible because permanent injury has not yet occurred
Infarction
death of a body tissue, usually caused by interruption of its bloody supply
