Cardiovascular System
Dr. Mohanad R. Alwan
Components
Heart pumps blood
Vessels Arteries carry blood away from the heart and veins carry blood back to the heart
Blood fluid that carries nutrients essential to cell function
Heart Anatomy
Approximately the size of your fist Location Superior surface of diaphragm Left of the midline Anterior to the vertebral column, posterior to the sternum
Size, Shape and Position
Oblique Position Located in mediastinum, between lungs Apex = Left of Midline (5th ICS), inferior end, tapers to point Base (posterior surface) sits on vertebral column, broad superior portion of heart 3.5 in. wide at base, weighs 10 oz
Location of Heart in Chest
Superior Right = 3rd Costal Cartilage,1right midsternum Superior Left = 2nd Costal Cartilage, 1 left midsternum Inferior Right = 6th Costal Cartilage,1right midsternum Inferior Left = 5th Intercostal Space at Midclavicular line
Heart Anatomy
Heart
Hollow, muscular organ 300 grams (size of a fist) 4 chambers found in chest between lungs surrounded by membrane called Pericardium Pericardial space is fluid-filled to nourish (nutrient) and protect the heart.
I. Anatomy of the Heart
A. Coverings Pericardium fibrous pericardium parietal pericardium visceral pericardium B. Heart wall layers
1. Epicardium
2. Myocardium
3. Endocardium
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Coverings of the Heart: Anatomy
Pericardium a double-walled sac around the heart composed of:
A superficial fibrous pericardium A deep two-layer serous pericardium The parietal layer lines the internal surface of the fibrous pericardium The visceral layer or epicardium lines the surface of the heart They are separated by the fluid-filled pericardial cavity
Coverings of the Heart
The pericardium:
Protects and anchors the heart Prevents overfilling of the heart with blood Allows for the heart to work in a relatively friction-free environment
Pericardial Layers of the Heart
Heart Wall
Epicardium visceral layer of the serous pericardiumprotects heart
Myocardium (middle layer) Cardiac muscle layer forming the bulk of the heart Fibrous skeleton of the heart crisscrossing, interlacing layer of connective tissue. Contracts movment Endocardium Endothelium connective tissue (CT) Lines the heart Creates the valves endothelial layer of the inner myocardial surface
Functions of the Heart
Generates blood pressure Routes blood
Heart separates pulmonary and systemic circulation
Ensures one-way blood flow
Heart valves ensure one-way flow
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Functions of the Heart
Regulates blood supply
Changes in contraction rate and force match blood delivery to changing metabolic needs Most healthy people can increase cardiac output by 300500%
Heart failure is the inability of the heart to provide enough blood flow to maintain normal metabolism
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Heart Anatomy
Heart Supplies oxygenated blood to all cells in the body!! The heart pumps about 100,000 times and moves 7200 liters (1900 gallons) of blood every day.
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Heart Anatomy
The heart has four chambers. Two atriums act as collecting reservoirs. Two ventricles act as pumps. The heart has four valves for: Pumping action of the heart. Maintaining unidirectional blood flow.
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Chambers, Vessels, and Valves
1. Four chambers upper chambers right and left atria Collects blood lower chambers right and left ventricle pumps blood from heart 2. Arteries Carry blood away from heart
3. Veins
Blood toward heart
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Atria of the Heart
Atria are the receiving chambers of the heart Each atrium has a protruding auricle (small conical pouch that projects from each atrium of the heart ) Pectinate muscles mark atrial walls Blood enters right atria from superior and inferior venae cavae and coronary sinus Blood enters left atria from pulmonary veins
Brachiocephalic trunk Superior vena cava Right pulmonary artery Ascending aorta Pulmonary trunk Right pulmonary veins Right atrium Right coronary artery (in coronary sulcus) Anterior cardiac vein Right ventricle Marginal artery Small cardiac vein Inferior vena cava (b)
Left common carotid artery Left subclavian artery Aortic arch Ligamentum arteriosum Left pulmonary artery Left pulmonary veins Left atrium
Auricle
Circumflex artery Left coronary artery (in coronary sulcus) Left ventricle Great cardiac vein
Anterior interventricular artery (in anterior interventricular sulcus) Apex
Figure 18.4b
Ventricles of the Heart
Ventricles are the discharging chambers of the heart Papillary muscles and trabeculae carneae muscles mark ventricular walls Right ventricle pumps blood into the pulmonary trunk Left ventricle pumps blood into the aorta
Heart Chambers
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Heart Chambers and Valves
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Right Heart Chambers
Right Atrium (forms most of posterior of heart)
Receives O2-poor blood from body via vena cava (IVC, SVC, ) ->
The sinoatrial node sends an impulse that causes
the cardiac muscle tissue of the atrium to contract in a coordinated, wave-like manner. The tricuspid valve, which separates the right atrium from the right ventricle, opens to allow the de-oxygenated blood collected in the right atrium to flow into the right ventricle.
Structure of Right Atrium Ventral wall = rough Pectinate muscle Fossa Ovalis- on interatrial septum, remnant of Foramen Ovale
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Right Ventricle
The right ventricle receives de-oxygenated blood from the right atrium (contracts). The pulmonary valve leading into the pulmonary artery is closed, allowing the ventricle to fill with blood. Once the ventricles are full, they contract. As the right ventricle contracts, the tricuspid valve closes and the pulmonary valve opens. The closure of the tricuspid valve prevents blood from backing into the right atrium and the opening of the pulmonary valve allows the blood to flow into the pulmonary artery toward the lungs.
Pumps blood to lungs via Pulmonary Semilunar Valve in pulmonary trunk
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Right Heart Chamber
Structure of Right Ventricle
Trabeculae Carnae along ventral surface Papillary Muscle-coneshaped muscle to which chordae tendinae are anchored Moderator Band-muscular band connecting anterior papillary muscle to interventricular septum
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Left Heart Chambers: Systemic Circuit
Left Atrium
The left atrium receives oxygenated blood from the lungs through the pulmonary vein. As the contraction triggered by the sinoatrial node progresses through the atria, the blood passes through the mitral valve into the left ventricle.
Pectinate Muscles line only auricle
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Left Ventricle
Left Ventricle (forms apex of heart)
The left ventricle receives oxygenated blood as the left atrium contracts via bicuspid valve. The blood passes through the mitral valve into the left ventricle. Once the ventricles are full, they contract, the mitral valve closes and the aortic valve opens than Pumps blood into aorta via Aortic Semilunar Valve to body. The closure of the mitral valve prevents blood from backing into the left atrium and the opening of the aortic valve allows the blood to flow into the aorta and flow throughout the body.
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Left Ventricle
Same structures as Rt
Ventricle: Trabeculae carnae, Papillary muscles, Chordae tendinae No Moderator Band
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Gross Anatomy of Heart: Frontal Section
Figure 18.4e
The Heart Valve
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The Cardiovascular System (The Heart valve)
Heart valves ensure unidirectional blood flow through the heart
The Heart valve:
Bicuspid (mitral) valve. Tricuspid valve. Pulmonary valve. Aortic valve.
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Valves of the Heart
R Atrioventricular
Tricuspid Heart sounds
L Atrioventricular
Mitral Heart sounds
Pulmonary
Semilunar Heart sounds
Aortic
Semilunar Heart sounds
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Heart Valves: Lub*-Dub**
*Tricuspid Valve: Right AV valve
3 Cusps (flaps) made of endocardium and CT Cusps anchored in Rt. Ventricle by Chordae Tendinae Chordae Tendinae prevent inversion of cusps into atrium Flow of blood pushes cusps open When ventricle in diastole (relaxed), cusps hang limp in ventricle Ventricular contraction increases pressure and forces cusps closed
This is the tricuspid valve. The leaflets, thin and delicate. Just like the mitral valve, the leaflets have thin chordae tendineae that attach the leaflet margins to the papillary muscles of the ventricular wall below.
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Heart Valves: Lub*-Dub**
*Bicuspid (Mitral) Valve: Left AV valve
2 cusps anchored in Lft. Ventricle by chordae tendinae Functions same as Rt. AV valve
**Semilunar valves: prevents backflow in large arteries
Pulmonary Semilunar Valve: Rt Ventricle and Pulmonary Trunk Aortic Semilunar Valve: Left Ventricle and Aorta 3 cusps: blood rushes past theyre flattened, as it settles theyre pushed down (valve closed)
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a normal tricuspid aortic valve
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Operation of Atrioventricular Valves
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Operation of Semilunar Valves
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External Heart: Major Vessels of the Heart (Anterior View)
Vessels returning blood to the heart include:
Superior and inferior venae cavae Right and left pulmonary veins
Vessels conveying blood away from the heart include:
Pulmonary trunk, which splits into right and left pulmonary arteries Ascending aorta (three branches) brachiocephalic, left common carotid, and subclavian arteries
External Heart: Major Vessels of the Heart (Posterior View)
Vessels returning blood to the heart include: Right and left pulmonary veins Superior and inferior venae cavae.
Vessels conveying blood away from the heart include: Aorta Right and left pulmonary arteries
Brachiocephalic trunk Superior vena cava Right pulmonary artery Ascending aorta Pulmonary trunk Right pulmonary veins Right atrium Right coronary artery (in coronary sulcus) Anterior cardiac vein Right ventricle Marginal artery Small cardiac vein Inferior vena cava (b)
Left common carotid artery Left subclavian artery Aortic arch Ligamentum arteriosum Left pulmonary artery Left pulmonary veins Left atrium
Auricle
Circumflex artery Left coronary artery (in coronary sulcus) Left ventricle Great cardiac vein
Anterior interventricular artery (in anterior interventricular sulcus) Apex
Figure 18.4b
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