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Understanding EKGs-1
Based on the book by Beasley, 2nd Edition
Question | Answer |
---|---|
Why is a thorough understanding of the structure of the heart necessary for EKGs? | Students need a foundation upon which to build the knowledge of basic dysrhythmia for interpretation. |
What is the most important muscle in the human body? | The heart |
Why is the heart a two-sided pump? | Because the heart is divided by the left and right sides with each side having a pump. |
What is located in the upper chambers of the heart? | The atrium (plural = atria) |
What is located in the lower chambers of the heart? | The ventricles |
How many hollow chambers exist in the heart? | Four (4) |
What separates the upper chambers? | The interatrial septum |
What separates the lower (or inferior) chambers? | The interventricular septum |
How are the atria and ventricles divided on the exterior of the heart? | By the atrioventricular grooves |
How are the ventricles separated externally? | By the anterior and posterior interventricular grooves |
True or False - The muscle fibers of the ventricles and atria are continuous. | True |
Why is the location of the heart an important aspect of anatomy? | To perform CPR and the placement of electrodes |
What is the central section of the thorax (chest cavity)? | Mediastinum |
What is in front of the spinal column, behind the sternum and between the lungs? | Mediastinum |
What part of the heart lies above the diaphram? | Apex |
What part of the heart lies below the third (3rd) rib? | Base |
Although the average heart is 5 x 3 inches or 12 x 7.5 centimeters, what determines the size of the heart in a human? | The size of the individual, as well as their athletic ability, fat content, and genetic make up. |
How can an EKG Technician determine the approximate size of an individuals heart? | By the size of the owners fist. |
Describe the coronary sinus? (Hint - 3 main features) | 1. Short trunk2. Receives deoxygenated blood from the veins of the myocardium3. Empties into the right atrium |
What is another name for the coronary sinus? | The GREAT cardiac vein |
Where is the base of the heart? | At the top of the heart muscle |
Where is the apex of the heart? | At the bottom of the heart muscle |
What is the serous "watery" membrane enveloping the lungs and lining the walls of the pleural cavity? | The pleaura of the heart |
What has direct contact with the pleura? | The outer layer of the pariental pericardium |
What is the pleural cavity? | The pleural cavity is a tough, inelastic fibrous connective tissue. |
What is the closed, two-layered sac that surrounds the heart? | The pericardium |
What is the thin, serous "watery" inner layer of the pericardium and is contiguous with the epicardium? | The visceral pericardium |
What is inflammation of the serous pericardium? | Pericarditis |
Although the cause is unknown, what may cause pericarditis? | Infection or disease of the connective tissue |
What can cause severe pain and may be confused with the pain of a myocardial infarction (MI)? | Pericarditis |
How many Primary layers of tissue compose the heart wall? | Three (3) |
What is the smooth outer surface of the heart? | Epicardium |
What is the name of the thick middle layer of the heart? | Myocardium |
Which layer of the heart is the thickest of the three layers of the heart wall? | Myocardium |
What is the myocardium composed of? | Cardiac muscle cells |
What is the purpose of the myocardium? | The myocardium is responsible for the heart's ability to contract. |
What is the name of the innermost layer of the heart? | Endocardium |
The endocardium is composed of what kind of connective tissue? | Thin connective tissue |
What is the purpose of the endocardium? | The endocardium, smooth inner surface of the heart and heart valves, allows blood to flow more easily throughout the heart. |
How many valves of the heart allow blood to flow in only one (1) direction? | Four (4)Atrioventricular valves are tricuspid and bicuspid (mital) valvesSemilunar valves are the pulmonic and aortic valves. |
How many sets of valves are they and what are they called? | There are two (2) set of heart valves:1. Atrioventricular valves2. Semilunar valves |
Which valve has three cusps and is located between the right atrium and right ventricle? | Tricuspid valve |
What does diastole mean? | dilation |
What fine chords of dense connective tissue are attached to papillary muscles in the wall of the ventricles? | Chordae tendineae |
Which valve is similar in structure to the Tricuspid valve, but only has two cusps and is located between the left atrium and left ventricle? | Mitral or Bicuspid Valve |
How do the chordae tendineae and papillary muscles work together? | The chordae tendineae and papillary muscles prevent the cusps from fluttering back into the atrium and disrupting blood flow through the heart. |
What is the purpose of the semilunar valves? | The semilunar valves prevent backflow of blood into the ventricles. |
How did the semilunar valves get their name? | Each semilunar valve contains three semilunar (or moon-shaped) cusps. |
What is the semilunar valve located between the right ventricle and the pulmonary artery? | Pulmonary valve |
What is the semilunar valve located between the left ventricle and the aorta? | Aortic valve |
What causes the opening and closing of the semilunar valves? | Chamber pressure |
What happens during ventricular systole (contraction of the ventricles)? | The atrioventricular valves close and the semilunar valves open. |
What happens during ventricular diastole (relaxation of the ventricles)? | The aortic and pulmonic valuves are closed and the mitral and tricuspid valves are open. |
What happens to the coronary arteries during ventricular diasole? | The passive filling of the coronary arteries |
What are the three blood vessels or vasculature? | Arteries, veins, and capillaries |
What blood vessel is thick-walled and muscular? | Arteries |
Why are arteries thick-walled and muscular? | Arteries function under high pressure in order to convey blood from the heart out to the rest of the body. |
What blood vessels branch off of arteries into smaller blood vessels? | Arterioles |
With the exception of pulmonary and umbilical arteries, what do arteries carry? | Oxygenated blood |
How do arteries regulate blood pressure? | Through functional changes in peripheral vascular resistance |
What are the three (3) layers of an artery that are sometimes called tunics (coats or coverings)? | 1. Intima2. Media3. Adventitia |
What is the purpose of arteries? | Arteries convey blood from the heart out to the rest of the body. |
What is the innermost layer of an artery and consists of endothelium and inner elastic membrane? | Tunica intima |
What is the middle layer of an artery and consists of smooth muscle cells? | Tunica media |
How is the blood flow regulated in the tunica media? | In the tunica media, the middle layer, the blood flow through the vessel is regulated by constriction or dilation. |
What is a decrease in the diameter of the blood vessel, which produces a decrease in blood flow? | Vasoconstriction |
What is an increase in the diameter of the blood vessel, which produces an increase in blood flow? | Vasodilation |
What is the outermost layer of a blood vessel, which is composed of various connective tissues? | Tunica adventitia |
What arises from the trunk of the aorta and functions to carry oxygenated blood throughout the myocardium? | The right and left coronary arteries |
What is called the GREAT cardiac vein? | The coronary sinus |
The ________ _________ is a short trunk that serves to receive deoxygenated blood from the veins of the myocardium & empties into the right atrium. | coronary sinus |
What blood vessels drain blood directly from the capillary beds and unite to form a vein. | Venules |
Which blood vessels have 3 layers? | Veins and arteries have 3 layers. |
What blood vessels carry blood back to the heart? | Veins |
Which blood vessels operate under low pressure, are thin walled, and have one-way valves? | Veins |
Which vein does NOT convey deoxygenated blood? | Pulmonary vein |
Which veins of the body empty into the two largest veins, the superior and inferior vena cava? | Large veins |
Which veins empty deoxygenated blood into the heart's right atrium? | Superior and inferior vena cava |
Which have the thinnest of all blood vessels? | Capillaries |
Which blood vessel is the most numerous? | Capillaries |
Which blood vessel are so tiny that red blood vessels must "march through in single file" | Capillaries |
Blood flows from the __________ into the capillaries. | Arterioles |
Where is the vast majority of gas exchanged occur in the body? | Capillaries |
What transports oxygenated blood into the capillaries? | Arterioles |
Capillaries allow for the exchange of __________, _____________, and ___________ _______ between the blood and body tissues. | Oxygen, nutrients, and waste products |
Which blood vessel is viewed as "connectors" between arteries and veins. | Capillaries |
What receives the deoxygenated blood, which travels back to the heart via the venous system? Hint: It is the smallest of veins. | Venules |
What is the definition of circulation? | Circulation is the movement through a course (in the body) which leads back to the initial point (the heart). |
Which two (2) major components compose the circulatory system? | 1. Pulmonary circulation2. Systemic circulation |
Which cycle is this? The blood leaves the heart through the right ventricle and travels into the pulmonary artery to the lungs and back through the pulmonary veins to the left atrium. | Pulmonary circulation |
What is critical to the pulmonary circulation? | Tissue perfusion is based on adequate gas exhange within the alveolar capillary membranes in the lungs. |
Which cycle is this? The blood leaves the left ventricle and travels through the arteries, capillaries, and veins of the entire body system and back to the primary receptacle of the heart (the right atrium). | Systemic circulation |
How are the tissues in our body maintained? | By both the pulmonary and systemic circulations. |
Describe systemic circulation, starting from the left side of the heart. | (Heart, left side) → Aorta → Arteries → Arterioles → Capillaries → Venules → Veins → Vena cava → (Heart, right side) |
Describe pulmonary circulation, starting from the right side of the heart. | (Heart, right side) → Pulmonary arteries → (Lungs) → Pulmonary vein → (Heart, left side) |