29ANATOMY OF CARDIOVASCULAR SYSTEM
Anatomy of Cardiovascular System
Cavities
Serous membrane = Serosa
2 Layers
Between them = Serous Cavity containing Serous Fluid
Serous fluid is blood filtrate + secretions by 2 layers of membrane
Allows movement of organs with reduced friction
Types of Serous Membranes
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Pleural Cavities
Pleural Cavities
holds layers together
superior surface of diaphragm
lateral surface of mediastinum
external surface of lungs
Mediastinum
DIVISIONS
Superior
Inferior
Anterior = ventral parietal pleura
Posterior = dorsal parietal pleura
Inferior = diaphragmatic pleura
The Diaphragm
Skeletal Muscle
Dome-shaped (relaxed)
Flattens (contracts)
I: Central tendon
Superior View
Action of the Diaphragm
Contraction during inspiration
Air moves into lungs (highlow pressure)
Forced contraction (voluntary)
Pushes on abdominal organs to move contents out
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Openings of Diaphragm
2 = Esophageal Hiatus for Esophagus and Vagus nerve
3 = Foramen in Central Tendon for Inferior Vena Cava
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2
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Parts and regions of the thorax
Boundaries
Superiorlyjugular notch, sternoclavicular joint, superior border of clavicle, acromion, spinous processes of C7
Inferiorlyxiphoid process, costal arch, 12th and 11th ribs, vertebra T12
Regions
Landmarks of thorax
Jugular notch corresponds with
The 2th thoracic vertebra in male, the 3th thoracic vertebra in female
Sternal angle corresponds with
The lower border of 4th thoracic vertebra
The bifurcation of trachea in the adult
The beginning of aortic arch which ends posteriorly at the same level
The esophagus is crossed by the left main bronchus
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Landmarks of thorax
Xiphoid processxiphisternal synchondrosis lies opposite the body of the 9th thoracic vertebra
Clavicle
Thoracic wall
Superficial structures
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Thoracic wall
Deep structures
Deep fascia
Superficial layer
Intercostal space
Internal thoracic vessels
Descends into thorax 1.2cm lateral to edge of sternum
Ends at the sixth costal cartilage by dividing musculophrenic and superior epigastric arteries
Parasternal ln.
Heart Anatomy
Location
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Heart Anatomy
Figure 18.1
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
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Coverings of the Heart: Physiology
The pericardium:
Prevents overfilling of the heart with blood
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Pericardial Layers of the Heart
Figure 18.2
Heart Wall
Myocardium – cardiac muscle layer forming the bulk of the heart
Fibrous skeleton of the heart – crisscrossing, interlacing layer of connective tissue
Endocardium – endothelial layer of the inner myocardial surface
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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 (Anterior View)
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External Heart: Anterior 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
External Heart: Major Vessels of the Heart (Posterior View)
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Arteries – right coronary artery (in atrioventricular groove) and the posterior interventricular artery (in interventricular groove)
Veins – great cardiac vein, posterior vein to left ventricle, coronary sinus, and middle cardiac vein
External Heart: Vessels that Supply/Drain the Heart (Posterior View)
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External Heart: Posterior View
Gross Anatomy of Heart: Frontal Section
Figure 18.4e
Atria of the Heart
Each atrium has a protruding auricle
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
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Ventricles 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
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Pathway of Blood Through the Heart and Lungs
Right atrium tricuspid valve right ventricle
Right ventricle pulmonary semilunar valve pulmonary arteries lungs
Lungs pulmonary veins left atrium
Left atrium bicuspid valve left ventricle
Left ventricle aortic semilunar valve aorta
Aorta systemic circulation
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Pathway of Blood Through the Heart and Lungs
Figure 18.5
Coronary Circulation
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Coronary Circulation
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
coronary veins coronary sinus right atrium
(inferior to opening
Coronary Circulation: Arterial Supply
Coronary Circulation: Venous Supply
Heart Valves
Atrioventricular (AV) valves lie between the atria and the ventricles
AV valves prevent backflow into the atria when ventricles contract
Chordae tendineae anchor AV valves to papillary muscles
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Heart Valves
Aortic semilunar valve lies between the left ventricle and the aorta
Pulmonary semilunar valve lies between the right ventricle and pulmonary trunk
Semilunar valves prevent backflow of blood into the ventricles
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Heart Valves
Heart Valves
Atrioventricular Valve Function
Semilunar Valve Function
Microscopic Anatomy of Heart Muscle
Cardiac muscle is striated, short, fat, branched, and interconnected
The connective tissue endomysium acts as both tendon and insertion
Intercalated discs anchor cardiac cells together and allow free passage of ions
Heart muscle behaves as a functional syncytium
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Vena Cava
Receives blood from regions above diaphragm
Formed from Rt + Lft Brachiocephalic Veins cranially
Azygos Vein empties into it just superior to heart
Empties into Right Atrium
Formed from Rt + Lft Common Iliac Veins
Empties into Right Atrium
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Veins of Mediastinum
runs superiorly
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