Chapter 18 -- The Heart Flashcards
What part of the body is the heart found?
The mediastinum of the thoracic cavity.
Where is the base and apex found on the heart?
The base is the superior part of the heart.
The apex is the inferior part of the heart.
What is the pericardium?
The double-layer closed sac that surrounds the heart
What are the two main layers of the pericardium?
Fibrous Pericardium: Tough outer layer.
Serous Pericardium: Thin transparent inner layer.
What are the two sub layers of the serous pericardium?
Parietal Pericardium: Lines the fibrous layer.
Visceral Pericardium: Covers heart surface.
What is the pericardial cavity?
The space between the parietal and visceral pericardium that is filled with pericardial fluid.
What are the three layers of the heart tissue?
Epicardium
Myocardium
Endocardium
Describe the epicardium
Smooth outer surface of the heart. Protects against friction during the hearts beating.
Describe the myocardium
Thick middle layer. Only place that contains cardiac muscle. Responsible for contraction and pumping of heart.
Describe the endocardium
Innermost layer of heart. Reduces friction as blood passes through the heart.
What is coronary circulation?
Circulation of blood that only supplies the heart muscle itself.
Describe the right coronary artery
Smaller of the two coronary arteries. Supplies blood to posterior and inferior part of the heart.
Describe the left coronary artery
Major part of this artery called Anterior Interventricular Artery. Supplies blood to most of the anterior part of the heart.
What is the function of the coronary veins?
They drain deoxygenated blood from the heart muscle.
What are the two coronary veins?
Great Cardiac Vein: Found in left heart.
Small Cardiac Vein: Found in Right Heart.
What part of the heart does the coronary veins bring their blood to?
Coronary Sinus, which then empties into the Right Atrium
What are the two atrium’s of the heart?
Two upper chambers of heart.
Right Atrium: Receives Deoxygenated blood to heart from body.
Left Atrium: Receive blood from pulmonary veins, receives oxygenated blood from the lungs.
What are the three major openings of the right atrium that receive blood?
Superior Vena Cava: Receives deoxygenated blood from upper body.
Inferior Vena Cava: Receives deoxygenated blood from lower body.
Coronary Sinus: Receives deoxygenated blood from the heart only.
What are the two ventricles of the heart?
Two Lower Chambers of Heart
Right Ventricle: carries deoxygenated blood to the lungs.
Left Ventricle: Carries oxygenated blood to the aorta which supplies body.
What the tissue that separates the two atriums?
Interatrial Septum. Contains the depression called the fossa ovalis which is the remenant of a gap that was present during time as a fetus.
What is the tissue that separates the two ventricles?
Interventricular Septum
What type of blood is found in the right side of the heart (right atrium & right ventricle)?
Deoxygenated blood that is low in O2 and high in CO2
What type of blood is found in the left side of the heart (left atrium & left ventricle)?
Oxygenated blood that is high in O2 and low in CO2
What is the function of arteries?
Carry blood away from the heart to the body.
What is the function of veins?
Carry blood toward the heart from the body.
What is the function of capillaries?
Small blood vessels throughout the body where gases, nutrients, and cell waste enter the blood.
What part of the heart is the hardest working?
The left ventricle because it has to have the strongest contractions in order to get blood to travel throughout the whole body. This is why the wall of the left ventricle is thicker.
Describe the AV Valves?
AV valves prevent backflow of blood back into the atria. This valve separate the atrium and ventricles.
What are the two AV Valves found in the heart?
Tricuspid Valve: Separate R Atrium from R Ventricle.
Bicuspid Valve: Separate L Atrium from L Ventricle.
Describe semilunar Valves?
Halfmoon valves that prevent bloodflow from major vessels back into the ventricles.
What are the two semilunar valves?
Aortic Valve: Seperates Aorta from the Left Ventricle
Pulmonary Valve: Separates pulmonary trunk from right ventricle.
What are the functions of the conduction system of the heart?
Conduct action potential that contracts the heart muscle.
Where is the SA Node and what is its function?
Found in the right atria near the entrance to the superior vena cava.
It functions as the natural pacemaker of the heart. It generates action potential and causes the atria of the heart to contract.
What is the AV Node and what is its function?
Found below the SA node close to the right AV Valve.
Allows for the completion of the atrial contraction then after begins contraction of the ventricle.
What are the three areas of the extention of the AV Node?
AV Bundle: Reaches through the interventricular septum.
Right and Left Bundle Branches: Extend through each side of the septum to the R&L Ventricles.
Purkinje Fibers: Thin extensions off of the R&L Bundle Branches that extend into ventricular muscle cells.
What factors lead to depolarization?
Calcium ions move through voltage-gated channels into cell.
Sodium ions move through non-gated channels into cells.
Potassium ions are trapped inside cells.
What is depolarization?
Contraction of heart muscle.
What ion has the leading role in the process of depolarization?
Calcium
Describe repolarization
Occurs when calcium channels close and potassium is able to leave the cell.
Describe the P wave of the electrocardiogram
First portion of wave where depolarization of the atria happens, causing atrial contraction.
Describe the QRS wave of the electrocardiogram
Second large portion of wave that depicts ventricular depolarization, causing ventricular contraction.
Describe the T wave of the electrocardiogram
Third long portion of wave that depicts repolarization of ventricles, causing relaxation of ventricles.
What is systole in the cardiac cycle?
When the heart rhythmically contracts
What is diastole in the cardiac cycle?
When the heart relaxes.
Describe the two sounds of the heartbeat?
First heart sound: Closure of AV valves when the ventricle contracts.
Second heart sound: Closure of SL valves when blood gets into main vessel.
What is the word for listening to the internal sounds of the body using a stethoscope?
Auscultation
What are the three types of arteries?
Elastic: Large diameter arteries
Muscular: Medium diameter arteries
Arterioles: Small diameter arteries.
What are the smallest size vessels that is the site of gas exchange?
Capillaries
What are the three types of veins?
Venules: Smallest size veins
Small Veins
Medium/ Large Veins
This type of capillary has no gaps between the endothelial cells, and contains no fenestrae.
Continuous Capillaries
This type of capillary has small gaps or fenestrae and is highly permeable. And what are the two types of this capillary?
Fenestrated Capillaries
Fenestrated with diaphragm, fenestrated without a diaphragm.
This type of capillary has large diameter fenestrae.
Sinusoidal Capillaries
What is the innermost layer of vessel tissue?
Tunica Intima
Contains connective tissue layer, internal elastic membrane.
What is the middle layer of vessel tissue?
Tunica Media
Smooth muscle cells which contribute to vasoconstriction and vasodilation. External elastic membrane.
What is the outermost layer of vessel tissue called?
Tunica Externa
Dense connective tissue.
Describe Arteriosclerosis
General term for degeneration in arteries making them less elastic.
Describe Atherosclerosis
Deposition of plaque on walls
