cardiovascular system: the heart dr. michael p. gillespie
TRANSCRIPT
![Page 1: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/1.jpg)
Cardiovascular System: The Heart
Dr. Michael P. Gillespie
![Page 2: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/2.jpg)
Cardiovascular System
Blood Heart Blood vessels
![Page 3: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/3.jpg)
Heart
Propels the blood through the blood vessels to reach all of cells of the body.
It circulates the blood through an estimated 100,000 km (60,000 miles) of blood vessels.
![Page 4: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/4.jpg)
Heart
It beats 100,000 times every day (35 million beats / year).
It pumps about 5 liters (5.3 qt) each minute and 14,000 liters (3,600 gal) each day.
Cardiology – the study of the normal heart and diseases associated with it.
![Page 5: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/5.jpg)
Size And Shape
About the size of a closed fist. Cone-shaped. 12cm (5 in.) Long, 9cm (3.5 in.) Wide, and
6cm (2.5 in.) Thick. 250g (8 oz) in adult females and 300g (10
oz) in adult males.
![Page 6: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/6.jpg)
Location
Lies in the mediastinum (a mass of tissue between the sternum and the vertebral column).
2/3 of the mass is left of midline. A cone lying on its side.
![Page 7: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/7.jpg)
Anatomical Landmarks
The apex (pointed end) is directed anteriorly, inferiorly, and to the left.
The base (broad portion) is directed posteriorly, superiorly, and to the right.
Anterior surface – deep to sternum & ribs.
![Page 8: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/8.jpg)
Anatomical Landmarks
Inferior surface – rests upon diaphragm. Right border – faces the right lung. Left border (pulmonary border) – faces the
left lung.
![Page 9: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/9.jpg)
![Page 10: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/10.jpg)
Cardiopulmonary Resuscitation (CPR)
External pressure (compression) can be used to force blood out of the heart and into the circulation.
CPR is utilized when the heart suddenly stops beating.
Cardiac compressions with artificial ventilation of the lungs keeps oxygenated blood circulating until the heart can be restarted.
Self CPR (coughing).
![Page 11: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/11.jpg)
Pericardium
Pericardium – membrane that surrounds and protects the heart. Fibrous pericardium – tough, inelastic, dense irregular
CT. Prevents overstretching of the heart. Serous pericardium – thinner, more delicate layer.
Parietal layer. Visceral layer (epicardium) – adheres to the heart. Pericardial fluid lies in between these two layers in the
pericardial cavity.
![Page 12: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/12.jpg)
Layers Of The Heart Wall
Epicardium (visceral layer of the serous pericardium).
Myocardium – cardiac muscle tissue. Endocardium – smooth lining of the
chambers of the heart and valves (continuous with blood vessels).
![Page 13: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/13.jpg)
![Page 14: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/14.jpg)
Chambers Of The Heart
Atria – superior chambers. Auricle – pouchlike structure.
Ventricles – inferior chambers. Sulci – grooves on the surface of the heart
that contain blood vessels.
![Page 15: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/15.jpg)
Chambers Of The Heart
Right atrium – receives blood from three veins: superior vena cava, inferior vena cava, and coronary sinus. Tricuspid valve. Pectinate muscles. Interatrial septum. Fossa ovalis – depression (remnant of foramen
ovale).
![Page 16: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/16.jpg)
Chambers Of The Heart
Right ventricle – receives blood from right atrium. Trabeculae carneae – bundles of cardiac muscle tissue. Chordae tendineae – connects to the cusps of the
tricuspid valve which are connected to papillary muscles. Interventricular septum. Pulmonary valve into pulmonary arteries.
![Page 17: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/17.jpg)
Chambers Of The Heart
Left atrium – receives blood from the lungs through the pulmonary veins. Bicuspid (mitral) valve.
Left ventricle – receives blood from left atrium. Trabeculae carneae – bundles of cardiac muscle tissue. Chordae tendineae – connects to the cusps of the
bicuspid valve which are connected to papillary muscles. Aortic valve into the ascending aorta (largest artery).
![Page 18: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/18.jpg)
![Page 19: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/19.jpg)
![Page 20: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/20.jpg)
Myocardial Thickness
The function of the individual chambers determines their thickness.
The atria pump blood a short distance and consequently have thinner walls than the ventricles.
The left ventricle pumps blood a greater distance than the right at higher pressures and has a thicker wall.
![Page 21: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/21.jpg)
Fibrous Skeleton Of The Heart
Dense CT rings that surround the valves and prevent overstretching.
Provides insertion points for bundles of cardiac muscle fibers.
![Page 22: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/22.jpg)
![Page 23: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/23.jpg)
Atrioventricular (AV) Valves
Tricuspid and bicuspid valves. When the valve is open, the pointed cusps
point into the ventricle.
![Page 24: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/24.jpg)
Atrioventricular (AV) Valves
When atrial pressure is higher than ventricular pressure the valves open (the papillary muscles are relaxed and the chordae tendinae is slack.
When the ventricles contract the pressure forces the AV valves closed. The papillary muscles close concurrently.
Damaged valves allow regurgitation (flow back).
![Page 25: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/25.jpg)
![Page 26: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/26.jpg)
Semilunar (SL) Valves
The aortic and pulmonary valves. The SL valves open when the pressure in the
ventricles exceeds the pressure in the arteries.
![Page 27: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/27.jpg)
![Page 28: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/28.jpg)
Heart Valve Disorders
Stenosis (narrowing) – failure of the heart valve to open fully.
Insufficiency (incompetence) – failure of a valve to close fully.
Mitral stenosis – due to scar formation of a congenital defect.
![Page 29: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/29.jpg)
Heart Valve Disorders
Mitral insufficiency – backflow of blood from the left ventricle to the left atrium. Mitral valve prolapse (MVP) – one or both cusps
protrude into the left atrium during ventricular contraction.
Aortic stenosis – the aortic valve is narrowed.
![Page 30: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/30.jpg)
Heart Valve Disorders
Aortic insufficiency – backflow of blood from the aorta into the left ventricle.
Rheumatic fever – an acute systemic inflammatory disease. Antibodies produced to destroy the bacteria attack and inflame the CT of joints, heart valves and other organs.
![Page 31: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/31.jpg)
Systemic And Pulmonary Circulations
Two closed systems. The output of one becomes the input of
another with each beat of the heart.
![Page 32: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/32.jpg)
![Page 33: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/33.jpg)
![Page 34: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/34.jpg)
Coronary Circulation
The myocardium has its own blood vessels, the coronary circulation.
The coronary arteries branch from the ascending aorta and encircle the heart.
When the heart is contracting the coronary arteries are squeezed shut.
When the heart is relaxed, the high pressure from the aorta pushes blood into the coronary arteries and from the arteries to the coronary veins.
![Page 35: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/35.jpg)
Coronary Arteries
Two coronary arteries, right and left coronary arteries, branch from the ascending aorta and supply oxygenated blood to the myocardium.
![Page 36: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/36.jpg)
Coronary Arteries
Left coronary artery branches into: Anterior interventricular or left anterior
descending LAD (supplies ventricle walls). Circumflex branches (supplies left ventricle and
left atrium).
![Page 37: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/37.jpg)
Coronary Arteries
Right coronary artery branches into: Atrial branches (supplies right atrium). Posterior interventricular branch (supplies the
two ventricles). Right marginal branch (supplies the right
ventricle).
![Page 38: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/38.jpg)
Coronary Veins
The great cardiac vein (anterior) and the middle cardiac vein (posterior) drain into the coronary sinus.
Coronary Sinus – a large bascular sinus on the posterior surface of the heart.
![Page 39: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/39.jpg)
![Page 40: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/40.jpg)
Reperfusion Damage
Reperfusion is reestablishing the blood flow to the heart muscle after a blockage of a coronary artery.
Reperfusion damages the tissue further due to the formation of oxygen free radicals from the reintroduced oxygen.
![Page 41: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/41.jpg)
Histology Of Cardiac Muscle Tissue
Cardiac muscle fibers are shorter in length and less circular than skeletal muscle fibers.
Cardiac muscle fibers exhibit branching.
![Page 42: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/42.jpg)
Histology Of Cardiac Muscle Tissue
Usually one centrally located nucleus is present, although it may occasionally have two nuclei.
Intercalated disc connect neighboring fibers. The discs contain desmosomes, which hold the fibers
together. Mitochondria are larger and more numerous in
cardiac muscle fiber. Gap junctions allow for propagation of action
potentials.
![Page 43: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/43.jpg)
![Page 44: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/44.jpg)
Regeneration Of Heart Cells
Infarcted (dead) cardiac muscle tissue is replaced with non-contractile fibrous scar tissue.
A lack of stem cells limits the ability of the heart to repair damage.
Some stem cells from the blood migrate into the heart tissues and differentiate into functional muscle cells and endothelial cells.
![Page 45: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/45.jpg)
Autorhythmic Fibers: The Conduction System
Autorhythmic fibers are self-excitable and maintain the heart’s continuous beating. Act as a pacemaker, setting the rhythm of
electrical excitation that causes contraction of a heart.
Form a conduction system, that provides a path for the cycle of cardiac excitation through the heart.
![Page 46: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/46.jpg)
Sequence Of Cardiac Conduction
Sinoatrial (SA) node – undergo spontaneous depolarization (pacemaker potential) – propagates through the atria through gap junctions.
Atrioventricular (AV) node (bundle of his) – site where action potentials are conducted from the atria to the ventricles.
![Page 47: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/47.jpg)
Sequence Of Cardiac Conduction
Right and left bundle branches – propagate action potentials through the ventricles and the interventricular septum to the apex of the heart.
Purkinje fibers – conduct the action potentials from the apex, through the remainder of the ventricles stimulating contraction.
![Page 48: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/48.jpg)
Pacemaker
The SA node regulates the pace of the heart. At rest, it contracts approximately 100 time
per minute. Nerve impulses from the ANS and blood
born hormones (epinephrine) modify the timing and strength of each heartbeat.
![Page 49: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/49.jpg)
Pacemaker
Acetylcholine from the ANS slows the heart rate to about 75 bpm.
If the SA node becomes damaged, the AV node can pick up the job; However, at a slower rate (40 – 60 bpm).
If both nodes are damaged, an artificial pacemaker sends out electrical currents to stimulate the heart to contract.
![Page 50: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/50.jpg)
![Page 51: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/51.jpg)
Ectopic Pacemaker
If a site other than the SA node becomes self-excitable, it becomes an ectopic pacemaker.
It make operate occasionally, producing extra beats, or for a period of time.
Triggers: Caffeine, nicotine, electrolyte imbalances,
hypoxia, and toxic reactions to drugs.
![Page 52: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/52.jpg)
![Page 53: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/53.jpg)
Refractory Period
In cardiac muscle tissue, the refractory period lasts longer than the contraction period.
This prevents tetanus (maintained contraction).
![Page 54: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/54.jpg)
Electrocardiogram (ECG or EKG)
As action potentials propagate through the heart, they generate electrical currents that can be detected on the surface of the body.
An electrocardiogram is a recording of these signals.
An electrocardiograph is the instrument used to record the signals.
![Page 55: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/55.jpg)
Electrocardiogram (ECG or EKG)
Electrodes are positioned on the arms and legs (limb leads) and at six positions on the chest (chest leads).
12 different tracings are produced from different combinations of leads.
![Page 56: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/56.jpg)
Electrocardiogram (ECG or EKG)
If these tracings are compared to one another and to a normal tracing, it is possible to determine the following: If the conducting pathway is abnormal. If the heart is enlarged. If certain regions of the heart are damaged.
![Page 57: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/57.jpg)
Typical Lead II Record
Three clearly recognizable waves appear with each heartbeat.
P wave – atrial depolarization. QRS complex – rapid ventricular
depolarization. T wave – ventricular repolarization.
![Page 58: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/58.jpg)
![Page 59: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/59.jpg)
Changes In Wave Size
Large P waves – enlargement of the atrium. Large Q waves – myocardial infarction. Large R waves – enlarged ventricles. Flat T wave – insufficient oxygen. Large T wave – hyperkalemia (high blood
K+ levels).
![Page 60: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/60.jpg)
Stress Electrocardiogram (Stress Test)
Elevate the heart’s response to stress. Narrowed coronary arteries may carry
adequate blood supply at rest, but not during exercise.
![Page 61: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/61.jpg)
Changes In Time Span Between Waves
Time spans between waves are called intervals or segments.
P-Q interval – time between the beginning of the P wave and the beginning of the QRS complex.
The P-Q interval represents the time required for an action potential to travel through the atria, AV node and remaining fibers of the conduction system.
![Page 62: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/62.jpg)
Changes In Time Span Between Waves
The P-Q interval lengthens when the action potentials must travel around scar tissue from rheumatic fever.
The S-T segement is elevated in acute myocardial infarction and depressed when the heart receives insufficient oxygen.
The Q-T interval may be lengthened by myocardial damage, myocardial ischemia, or conduction abnormalities.
![Page 63: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/63.jpg)
Terminology
Systole – the phase of contraction. Diastole – the phase of relaxation. Cardiac cycle – all of the events associated
with one heartbeat (systole and diastole of the atria and systole and diastole of the ventricles).
![Page 64: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/64.jpg)
Heart Sounds
Auscultation – listening to sounds within the body (performed with a stethoscope).
During each cardiac cycle there are 4 heart sounds, but in a normal heart, only the first and second heart sounds (S1 and S2) are loud enough to be heard with a stethoscope.
![Page 65: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/65.jpg)
Heart Sounds
The first sound (S1), described as a lubb sound, is louder and longer than the second. Caused by closure of the AV valves after
ventricular systole begins. The second sound (S2), described as dupp
sound, is shorter and not as loud as S1. Caused by closure of the semilunar valves as
ventricular diastole begins.
![Page 66: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/66.jpg)
Heart Sounds
S3 is due to blood turbulence from rapid ventricular filling.
S4 is due to blood turbulence during atrial systole.
S3 and S4 are not normally heard.
![Page 67: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/67.jpg)
Heart Murmurs
A heart murmur is an abnormal sound consisting of a clicking, rushing, or gurgling noise that is heard before, between, or after the normal heart sounds. It can also mask the normal heart sounds.
Some heart murmurs are “innocent”; However, they usually represent a valve disorder.
![Page 68: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/68.jpg)
Congestive Heart Failure
In CHF, the heart is a failing pump. Causes include coronary artery disease,
congenital defects, long-term high blood pressure (increases afterload), myocardial infarctions, valve disorders. Pulmonary edema – left ventricle fails first. Peripheral edema – right ventricle fails first.
![Page 69: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/69.jpg)
Regulation Of Heart Rate
Autonomic regulation of heart rate. Proprioceptors, chemoreceptors, baroreceptors. Cardiac accelerator nerves.
Chemical regulation of heart rate. Hormones (epinephrine, norepinephrine, and
thyroid hormones) accelerate the heart rate. Cations.
![Page 70: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/70.jpg)
Terminology
Tachycardia – elevated resting heart rate. Bradycardia – a resting heart rate under 60
bpm. Hypothermia – lowering of the body
temperature, which slows the heart rate.
![Page 71: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/71.jpg)
![Page 72: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/72.jpg)
Disorders Of The Heart
Coronary artery disease (CAD). Arteriosclerosis and atherosclerosis.
![Page 73: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/73.jpg)
Disorders Of The Heart
Myocardial ischemia and infarction. Hypoxia. Angina pectoris.
![Page 74: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/74.jpg)
Disorders Of The Heart
Congenital defects. Coarctation of the aorta. Patent ductus arteriosus. Septal defect.
Atrial and ventricular. Tetralogy of Fallot.
![Page 75: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/75.jpg)
Disorders Of The Heart
Arrhythmias – irregularity of the heart rhythm. Heart block. Flutter and fibrillation. Ventricular premature contraction.
![Page 76: Cardiovascular System: The Heart Dr. Michael P. Gillespie](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e385503460f94b288f8/html5/thumbnails/76.jpg)
Medical Terminology
Angiocardiography – x-ray examination of the heart and great vessels with radiopaque dye.
Cardiac arrest. Cardiomegaly. Cor pulmonale (CP) – ventricular hypertrophy from
disorders that bring about hypertension in the pulmonary circulation.
Palpitation.