Cardiovascular System Cardiovascular System the Heart

2/20/2016

Cardiovascular System

• Blood • Heart The Cardiovascular System • Blood vessels Part 1

Cardiovascular System The Heart

• Functions • Four separate chambers in humans –Transport gases, wastes, food, hormones, blood cells – Also other mammals, birds • Systems affected • Double pump ‰ two closed circuits – Respiratory • 5 L/minute –Urinary –Digestive –Musculoskeletal –Immune system

Capillary beds of lungs where The Heart gas exchange occurs Pulmonary Circuit • Symmetrical in design, but not in position Pulmonary veins Pulmonary arteries Aorta and branches – 2/3 of mass to the left of midline Venae cavae Left atrium – 1/3 to right

Right atrium Left ventricle Heart Right ventricle Systemic Circuit

Oxygen-rich, Capillary beds of all CO 2-poor blood body tissues where Oxygen-poor, gas exchange occurs CO 2-rich blood

Figure 18.5

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Located within mediastinum

Midsternal line Superior Aorta vena cava Parietal 2nd rib pleura (cut) Pulmonary Left lung Sternum trunk Pericardium Diaphragm Point of (cut) maximal Apex of intensity Diaphragm heart (PMI) (a) (c)

Figure 18.1a Figure 18.1c

Pericardium Pericardium

– –Membrane surrounding and protecting the heart Double walled organ • Confines while still allowing free movement • Fibrous pericardium • Serous pericardium

Pericardium Pericardium

–Double walled organ –Double walled organ • Fibrous pericardium • Fibrous pericardium –Fibrous connective tissue • Serous pericardium –Prevents overstretching, protection, anchorage –Serous epithelium • Serous pericardium –Double layer » Parietal layer * Epithelial cells * Secrete serous fluid (thin mucus) * Fused to fibrous pericardium » Visceral layer (epicardium) * Thin connective tissue * Forms surface of heart

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Pericardium

• Pericardial cavity –Between visceral and parietal serous pericardium –Scant amount of serous fluid – accumulation may cause… • Pericarditis –Inflammation of pericardium –Sharp, stabbing chest pain –May be caused by viral infection, heart attack –Begins suddenly but resolves quickly

Muscular Wall of the Heart

• Three layers Pulmonary Fibrous pericardium trunk Parietal layer of –Epicardium serous pericardium • Also called the… Pericardium Pericardial cavity Myocardium Epicardium –Myocardium (visceral layer Heart –Endocardium of serous wall pericardium) Myocardium Endocardium Heart chamber

Figure 18.2

Muscular wall of the heart

• Epicardium Pulmonary Fibrous pericardium trunk Parietal layer of – Serous membrane serous pericardium Pericardium Pericardial cavity – Typicially infiltrated Myocardium Epicardium with fat in the elderly (visceral layer Heart of serous wall pericardium) Myocardium Endocardium Heart chamber

Figure 18.2

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Muscular wall of the heart Muscular wall of the heart

• Myocardium • Myocardium –Primarily cardiac muscle –Branching cardiac muscle cells –Bulk of heart –Connected to one another by crisscrossing connective tissue –Variable thickness fibers • Ventricles thicker than atria • Non-excitable – limits the spread of action potentials to specific • Left ventricle thicker than right pathways in the heart –Inner surface raised into finger- –Arranged in spiral or circular bundles like projections –Bundles interlace and effectively link all parts of the heart • Papillary muscles together

Myocardium Muscular wall of the heart

• Endocardium –Squamous epithelium • Cardiac Smooth, white muscle –Continuous with bundles endothelial linings of large blood vessels entering/exiting the heart

Figure 18.3

Muscular wall of the heart Anatomy of the Heart

• Endocardium • Chambers –Endocarditis – inflammation of the endocardium –Common in IV drug users –Leads to valve damage, emboli

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Anatomy of the Heart Anatomy of the Heart

• Chambers • Chambers –Right and left atria –Right and left ventricles • Separated by interatrial septum • Separated by interventricular septum • Coronary sulcus (atrioventricular groove ) encircles the junction of the atria and ventricles – Blood vessels that supply the myocardium rest inside • Auricles – Atrial appendages – Increase atrial volume

Anatomy of the Heart

• Ventricular septal defect (VSD)

Left ventricle

Right ventricle Interventricular septum

Figure 18.6

Major Vessels of the Heart

Left common carotid Brachiocephalic trunk Major Vessels of the Heart artery Left subclavian artery Superior vena cava Aortic arch Right pulmonary Ligamentum arteriosum • Numerous blood vessels are associated with the artery Left pulmonary artery Ascending aorta Left pulmonary veins heart… Pulmonary trunk Right pulmonary Auricle of veins left atrium Circumflex artery Right atrium Right coronary artery Left coronary artery (in coronary sulcus) (in coronary sulcus) Anterior cardiac vein Left ventricle Right ventricle Right marginal artery Great cardiac vein Anterior interventricular Small cardiac vein artery (in anterior Inferior vena cava interventricular sulcus) Apex (b) Anterior view

Figure 18.4b

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Major Vessels of the Heart – Entering Right Atrium

Left common carotid Atria Brachiocephalic trunk artery The Receiving Chambers Left subclavian artery Superior vena cava Aortic arch Right pulmonary Ligamentum arteriosum • Vessels entering right atrium artery Left pulmonary artery Ascending aorta Left pulmonary veins –Superior vena cava Pulmonary trunk

–Inferior vena cava Right pulmonary Auricle of –Coronary sinus veins left atrium Circumflex artery • Vessels entering left atrium Right atrium Right coronary artery Left coronary artery –Right and left pulmonary veins (in coronary sulcus) (in coronary sulcus) Anterior cardiac vein Left ventricle Right ventricle Right marginal artery Great cardiac vein Anterior interventricular Small cardiac vein artery (in anterior Inferior vena cava interventricular sulcus) Apex (b) Anterior view

Figure 18.4b

Major Vessels of the Heart – Entering Right Atrium Major Vessels of the Heart – Entering Right Atrium

Aorta Aorta Superior vena cava Superior vena cava Left pulmonary Left pulmonary Right pulmonary artery artery artery Right pulmonary Left atrium Left pulmonary Right pulmonary veins artery Left pulmonary veins Pulmonary trunk veins Auricle of left Right atrium Right atrium atrium Mitral (bicuspid) Right pulmonary valve Left atrium Inferior vena cava veins Great cardiac Fossa ovalis Aortic valve vein Coronary sinus Pectinate muscles Pulmonary valve Right coronary artery Tricuspid valve Posterior vein (in coronary sulcus) Left ventricle of left ventricle Right ventricle Papillary muscle Posterior Left ventricle Chordae tendineae Interventricular interventricular septum artery (in posterior Trabeculae carneae Epicardium interventricular sulcus) Apex Inferior vena cava Myocardium Middle cardiac vein Endocardium Right ventricle (d) Posterior surface view (e) Frontal section

Figure 18.4d Figure 18.4e

Major Vessels of the Heart – Entering Left Atrium Major Vessels of the Heart – Entering Left Atrium

Left common carotid Brachiocephalic trunk Aorta artery Left subclavian artery Superior vena cava Left pulmonary Superior vena cava Aortic arch artery Right pulmonary Right pulmonary Ligamentum arteriosum Left atrium artery Left pulmonary artery artery Left pulmonary Pulmonary trunk Ascending aorta Left pulmonary veins veins Pulmonary trunk Right atrium Mitral (bicuspid) Right pulmonary Auricle of Right pulmonary valve veins left atrium veins Fossa ovalis Circumflex artery Aortic valve Right atrium Pectinate muscles Pulmonary valve Right coronary artery Left coronary artery Tricuspid valve (in coronary sulcus) Left ventricle (in coronary sulcus) Papillary muscle Anterior cardiac vein Right ventricle Left ventricle Chordae tendineae Interventricular Right ventricle septum Trabeculae carneae Right marginal artery Great cardiac vein Epicardium Anterior interventricular Inferior vena cava Myocardium Small cardiac vein artery (in anterior Endocardium Inferior vena cava interventricular sulcus) Apex (b) Anterior view (e) Frontal section

Figure 18.4b Figure 18.4e

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Major Vessels of the Heart – Exiting Right Ventricle

Left common carotid Ventricles Brachiocephalic trunk artery The Discharging Chambers Left subclavian artery Superior vena cava Aortic arch • Right pulmonary Ligamentum arteriosum Vessel leaving the right ventricle artery Left pulmonary artery –Pulmonary trunk → right and le pulmonary arteries Ascending aorta Left pulmonary veins Pulmonary trunk • Vessel leaving the left ventricle Right pulmonary Auricle of –Aorta veins left atrium Circumflex artery Right atrium Right coronary artery Left coronary artery (in coronary sulcus) (in coronary sulcus) Anterior cardiac vein Left ventricle Right ventricle Right marginal artery Great cardiac vein Anterior interventricular Small cardiac vein artery (in anterior Inferior vena cava interventricular sulcus) Apex (b) Anterior view

Figure 18.4b

Major Vessels of the Heart – Exiting Right Ventricle Major Vessels of the Heart – Exiting Right Ventricle

Figure 18.4b Figure 18.4e

Major Vessels of the Heart – Exiting Left Ventricle Major Vessels of the Heart – Exiting Left Ventricle

Figure 18.4b Figure 18.4e

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Major Vessels of the Heart

Left common carotid Brachiocephalic trunk Coronary Arteries artery Left subclavian artery Superior vena cava Aortic arch Right pulmonary Ligamentum arteriosum • Supply blood to the heart wall itself artery Left pulmonary artery Ascending aorta Left pulmonary veins Pulmonary trunk

Right pulmonary Auricle of veins left atrium Circumflex artery Right atrium Right coronary artery Left coronary artery (in coronary sulcus) (in coronary sulcus) Anterior cardiac vein Left ventricle Right ventricle Right marginal artery Great cardiac vein Anterior interventricular Small cardiac vein artery (in anterior Inferior vena cava interventricular sulcus) Apex (b) Anterior view

Figure 18.4b

Heart Valves Pulmonary valve Aortic • Atrioventricular (AV) valves valve Area of –Prevent backflow into the atria when ventricles contract cutaway –Chordae tendineae (“heart strings”) anchor AV valve cusps to Mitral papillary muscles valve Tricuspid • Semilunar valves valve –Prevent backflow into the ventricles when ventricles relax

Unidirectional blood flow through the heart

Chordae tendineae Papillary attached to tricuspid valve flap muscle (c)

Figure 18.8c

Heart Valves Aorta Superior vena cava Left pulmonary artery • Right pulmonary Left atrium Atrioventricular artery Left pulmonary –Separate atria from ventricles Pulmonary trunk veins Right atrium • Tricuspid Mitral (bicuspid) – Right side Right pulmonary valve veins • Mitral (bicuspid) Fossa ovalis Aortic valve – Left side Pectinate muscles Pulmonary valve Tricuspid valve Left ventricle Right ventricle Papillary muscle • Chordae tendineae Interventricular Semilunar septum Trabeculae carneae –Separate ventricles from great arteries Epicardium Inferior vena cava • Myocardium Pulmonary semilunar Endocardium • Aortic semilunar (e) Frontal section

Figure 18.4e

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Myocardium Pulmonary valve Aortic valve Cardiac Circulation Tricuspid Area of cutaway (right atrioventricular) Mitral valve valve Tricuspid valve • The heart is two side-by-side pumps Mitral Myocardium (left atrioventricular) –Right side = pulmonary circuit valve Tricuspid • Vessels that carry blood to and from the lungs Aortic (right atrioventricular) –Left side = systemic circuit valve valve • Vessels that carry the blood to and from all body tissues Mitral Pulmonary (left atrioventricular) valve valve Aortic valve Pulmonary valve Aortic valve Pulmonary Area of cutaway valve Fibrous (b) skeleton Mitral valve Tricuspid valve (a) Anterior

Figure 18.8a

Capillary beds of lungs where Pathway of Blood Through the Heart gas exchange occurs Pulmonary Circuit Right atrium (via vena cava) Lungs Pulmonary veins Pulmonary arteries Aorta and branches Venae cavae Tricuspid valve Pulmonary veins Left atrium Right ventricle Left atrium Right atrium Left ventricle Heart Bicuspid valve Right ventricle Pulmonary semilunar valve Systemic Circuit Pulmonary trunk Left ventricle

Aortic semilunar valve Pulmonary arteries Oxygen-rich, Capillary beds of all CO -poor blood Aorta 2 body tissues where Lungs Oxygen-poor, gas exchange occurs CO 2-rich blood Systemic circulation

Figure 18.5

1 Blood returning to the heart fills atria, putting Direction of Aorta pressure against blood flow atrioventricular valves; Atrium Pulmonary atrioventricular valves are trunk forced open. Cusp of As ventricles 2 As ventricles fill, atrioventricular contract and atrioventricular valve flaps valve (open) hang limply into ventricles. intraventricular Chordae pressure rises, 3 Atria contract, forcing tendineae blood is pushed up additional blood into ventricles. against semilunar Papillary valves, forcing them Ventricle muscle open. (a) AV valves open; atrial pressure greater than ventricular pressure (a) Semilunar valves open

Atrium 1 Ventricles contract, forcing Cusps of As ventricles relax blood against atrioventricular atrioventricular valve cusps. valve (closed) and intraventricular pressure falls, blood 2 Atrioventricular valves flows back from close. Blood in arteries, filling the ventricle cusps of semilunar 3 Papillary muscles contract and chordae valves and forcing tendineae tighten, them to close. preventing valve flaps from everting into atria.

(b) AV valves closed; atrial pressure less than ventricular pressure (b) Semilunar valves closed

Figure 18.9 Figure 18.10

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Heart Sounds

• “lub-dup”

Coronary (Cardiac) Circulation Coronary (Cardiac) Circulation

• Blood from the chambers cannot serve as a functional blood • Arteries supply to the heart – Right and left coronary arteries • Heart muscle has its own blood supply – Branch off base of the aorta – Coronary circulation – Extensive branching throughout epicardium • Common for branches from right and left coronary arteries to unite – Anastomoses • Cardiac veins feed into coronary sinus directly into right atrium

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Aorta Pulmonary Superior Aorta vena cava trunk Superior vena cava Left pulmonary Left atrium Right pulmonary artery Anastomosis artery (junction of Left pulmonary Right pulmonary veins vessels) Left veins coronary Auricle of left Right atrium Right artery atrium atrium Left atrium Inferior vena cava Circumflex Great cardiac Right artery vein Coronary sinus coronary Right coronary artery artery Left Posterior vein (in coronary sulcus) ventricle of left ventricle Right Posterior Left ventricle ventricle Anterior interventricular Right interventricular artery (in posterior marginal Posterior artery Apex interventricular sulcus) artery interventricular Middle cardiac vein artery Right ventricle (a) The major coronary arteries (d) Posterior surface view

Figure 18.7a Figure 18.4d

Coronary sinus drains into right atrium Collateral Circulation

Superior vena cava • Benefits of anastomoses • Provides additional route of blood flow • Older heart attack patients are more likely to survive Anterior Great cardiac cardiac than younger ones vein s vein – Sudden clot formation vs gradual Coronary sinus

Small cardiac vein Middle cardiac vein (b) The major cardiac veins

Figure 18.7b