Transcript Fundamentals of Anatomy and Physiology, Second Edition

Chapter 14
THE CARDIOVASCULAR SYSTEM
Introduction
• Cardiovascular system: heart, blood and
blood vessels
• Cardiac muscle
– Makes up bulk of heart
– Provides force to pump blood
• Function: transports blood
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THE ANATOMY OF THE HEART
Introduction
• Located in the mediastinum
• Surrounded by pericardial sac
– Fibrous pericardium: outer layer
– Serous pericardium: inner layer
The Layers of the Heart Wall
• Epicardium: outermost layer
• Pericardial cavity: separates epicardium
and serous pericardium
• Myocardium: middle muscular layer
• Endocardium: lines the heart
The Layers of the Heart Wall
(cont’d.)
The Chambers of the Heart
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Upper chambers: right and left atria
Lower chambers: right and left ventricles
Chambers separated internally by septum
External separations
– Coronary sulcus: separates atria and ventricles
– Interventricular sulci: separate ventricles
The Chambers of the Heart
(cont’d.)
The Great Vessels of the Heart
• Superior vena cava
– Receives blood from upper body
• Inferior vena cava
– Receives blood from lower body
• Coronary sinus: drains blood from heart
The Great Vessels of the Heart
(cont’d.)
• Pulmonary trunk: right and left artery
– Carries deoxygenated blood to lungs
• Pulmonary veins (four): return oxygenated
blood to heart
• Ascending aorta: oxygenated blood out to
body
– Aortic arch, descending thoracic, abdominal
Four Chambers of the Heart and
Great Vessels
The Valves of the Heart
• Atrioventricular
– Tricuspid (three cusps)
• Between right atrium and right ventricle
– Bicuspid (two cusps)
• Between left atrium and right ventricle
– Cusps attach to ventricles by chordae
tendineae
The Valves of the Heart (cont’d.)
• Semilunar
– Pulmonary
• Right ventricle
• Pulmonary trunk exits the heart
– Aortic
• Left ventricle
• Ascending aorta leaves the heart
BLOOD FLOW THROUGH THE HEART
Blood Flow Through the Heart
(cont’d.)
• Two atria contract while ventricles relax
• Two ventricles contract while atria relax
• Deoxygenated blood returns from body to
right atrium
• Sent to right ventricle, which pumps blood
to lungs
Blood Flow Through the Heart
(cont’d.)
• Oxygenated blood returns to left atrium
• Sent to left ventricle
• Left ventricle sends blood to the body via
the ascending aorta
THE CONDUCTION SYSTEM OF THE HEART
The Conduction System of the
Heart (cont’d.)
• Sinoatrial (SA) node: pacemaker; initiates
impulse 
• Atrioventricular (AV) node: sends impulse
to AV bundle
• Bundle of His: sends impulses to both sides
of system
The Conduction System of the
Heart (cont’d.)
• Purkinje’s fibers: send impulse to
myocardial cells
The Conduction System of the
Heart (cont’d.)
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Animation – The Heart
• See the conduction system at work in the 3-D
Heart animation.
Click Here to Play Conduction System Animation
A CARDIAC CYCLE
A Cardiac Cycle (cont’d.)
• One cycle
– Atria contract / ventricles relax
– Ventricles contract / atria relax
• Systole: contraction phase
• Diastole: relaxation phase
SOME MAJOR BLOOD CIRCULATORY ROUTES
Some Major Blood Circulatory
Routes (cont’d.)
• Systemic circulation
– All blood leaving left ventricle (oxygenated)
– All blood returning to right atrium
(deoxygenated)
– Subdivisions
• Coronary circulation
• Hepatic portal circulation
Some Major Blood Circulatory
Routes (cont’d.)
• Pulmonary: blood flow to lungs for gas
exchange
• Cerebral: route to the brain
• Fetal: between developing fetus and
mother
ANATOMY OF BLOOD VESSELS
Anatomy of Blood Vessels
(cont’d.)
• Arteries and veins have three layers
– Tunica intima: innermost layers
– Tunica media: middle layer
– Tunica adventitia: outer layer
• Lumen: blood vessel cavity
• Anastomosis: junction of blood vessels
Anatomy of Blood Vessels
(cont’d.)
• Arteries: thicker and stronger than veins
• Arterioles: small arteries attach to
capillaries
• Capillaries: gas nutrient and waste
exchange
Anatomy of Blood Vessels
(cont’d.)
• Venules: connect capillaries to veins
• Veins: less elastic than arteries, contain
valves
MAJOR ARTERIES AND VEINS OF THE BODY
Ascending Aorta Branches
• Right and left coronary arteries branch off
and supply the heart
Aortic Arch Branches
• 1st branch: brachiocephalic artery
– Right common carotid artery and right
subclavian artery
• 2nd branch: left common carotid artery
– Left internal carotid artery and left external
carotid artery
Aortic Arch Branches
• 3rd branch: left subclavian artery
– Vertebral artery, axillary artery, brachial artery
and radial and ulnar arteries
Thoracic Aorta Branches
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10 pairs of intercostal arteries
Bronchial arteries
Esophageal arteries
Phrenic arteries
Abdominal Aorta Branches
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Celiac trunk
Superior and inferior mesenteric arteries
Right and left renal arteries
Right and left gonadal arteries
Lumbar arteries
Right and left common iliac artery
– Femoral artery
Abdominal Aorta Branches
(cont’d.)
• Veins
– Found closer to surface than arteries
– Converge with:
• Superior vena cava
• Inferior vena cava
– Veins are often named identically to arteries
Veins Merging into the Superior
Vena Cava
• Radial and ulnar veins form brachial vein
– Empties into axillary vein
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Cephalic vein
Basilic vein
Subclavian vein
Vertebral vein
Veins Merging into the Superior
Vena Cava (cont’d.)
• Internal jugular vein
• Right and left brachiocephalic veins
• Azygos vein
Veins Merging into the Inferior
Vena Cava
• Anterior and posterior tibial veins
• Peroneal vein
• Popliteal/femoral veins
– External iliac vein
• Great saphenous veins
• Right and left common iliac veins
Veins Merging into the Inferior
Vena Cava (cont’d.)
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Right and left gonadal veins
Right and left renal veins
Hepatic portal vein
Right and left hepatic veins
Animation – Ventricular
Fibrillation
• The following animation illustrates the seriousness of an ineffective
quivering action of the ventricles of the heart, known as ventricular
fibrillation
Click Here to Play Ventricular Fibrillation Animation
Animation – Congestive Heart
Failure
• Read about this condition in the Health Alert box on
Congestive Heart Failure (CHF) in your textbook.
• Now watch the congestive heart failure animation.
Click Here to Play Congestive Heart Failure Animation
Summary
• Named the layers of the heart wall
• Named the chambers and valves of the
heart
• Described blood flow through the heart
• Described the conduction system of the
heart
Summary (cont’d.)
• Discussed the stages of the cardiac cycle
• Compared the anatomy of a vein, artery
and capillary
• Named the major blood circulatory routes
and blood vessels