DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE
Cardiovascular System
CRT04101 · Anatomy, Physiology and Pathology
Study Cardiovascular System using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology.
The Cardiovascular System: The Heart
Harrison, MD
Chapter 18, Cardiovascular System
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
Chapter 18, Cardiovascular System
Heart Anatomy
Figure 18.1
Chapter 18, Cardiovascular System
- 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
Chapter 18, Cardiovascular System
- Coverings of the Heart: Physiology
- The Function of 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
Chapter 18, Cardiovascular System
Heart Wall
- Epicardium – visceral layer of the serous pericardium
- 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
Chapter 18, Cardiovascular System
- 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
- Subclavian arteries
External Heart: Major Vessels of the Heart (Anterior View)
Chapter 18, Cardiovascular System
Arteries – right and left coronary (in atrioventricular groove), marginal, circumflex, and anterior interventricular arteries Veins – small cardiac, anterior cardiac, and great cardiac veins External Heart: Vessels that Supply/Drain the Heart (Anterior View)
Chapter 18, Cardiovascular System
External Heart: Anterior View
Figure 18.4b
Chapter 18, Cardiovascular System
- 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
External Heart: Major Vessels of the Heart (Posterior View)
Chapter 18, Cardiovascular System
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)
Chapter 18, Cardiovascular System
External Heart: Posterior View
Figure 18.4d
Chapter 18, Cardiovascular System
- Gross Anatomy of Heart: Frontal Section
Figure 18.4e
Chapter 18, Cardiovascular System
- Atria of the Heart
- Atria are the receiving chambers 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
Chapter 18, Cardiovascular System
- 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
Chapter 18, Cardiovascular System
- Myocardial Thickness and Function
- Thickness of myocardium varies according to the function of the chamber
- Atria are thin walled, deliver blood to adjacent ventricles
- Ventricle walls are much thicker and stronger
- right ventricle supplies blood to the lungs (little flow resistance)
left ventricle wall is the thickest to supply systemic circulation
Chapter 18, Cardiovascular System
- Thickness of Cardiac Walls
Myocardium of left ventricle is much thicker than the right.
Chapter 18, Cardiovascular System
- 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
Chapter 18, Cardiovascular System
- Pathway of Blood Through the Heart and Lungs
Figure 18.5
Chapter 18, Cardiovascular System
Coronary Circulation
- Coronary circulation is the functional blood supply to the heart muscle itself
Collateral routes ensure blood delivery to heart even if major vessels are occluded
Chapter 18, Cardiovascular System
Coronary Circulation: Arterial Supply
Figure 18.7a
Chapter 18, Cardiovascular System
Coronary Circulation: Venous Supply
Figure 18.7b
Chapter 18, Cardiovascular System
Heart Valves
- Heart valves ensure unidirectional blood flow through the heart
- 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
Chapter 18, Cardiovascular System
Heart Valves
- Semilunar valves prevent backflow of blood into the ventricles
- Aortic semilunar valve lies between the left ventricle and the aorta
Pulmonary semilunar valve lies between the right ventricle and pulmonary trunk
Chapter 18, Cardiovascular System
Heart Valves
Figure 18.8a, b
Chapter 18, Cardiovascular System
- 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
- InterActive Physiology®:
Cardiovascular System: Anatomy Review: The Heart
PLAY
STRUCTURE OF BLOOD VESSELS
Chapter 18, Cardiovascular System
BLOOD VESSELS
- Made up of three layer
- -tunica externa-compose of loose fibrous connective tissue
- -tunica media-smooth muscles
- -tunica intima-endothelial cells
DIFFERENCES BTN VEIN AND ARTERY.
Chapter 18, Cardiovascular System
ARTERIES
CARRIES BLOOD AWAY OF THE HEART
- Large
- Thick-walled, Muscular
- Elastic
- Oxygenated blood
Exception Pulmonary Artery
- Carried under great pressure
- Steady pulsating
- Arterioles: smaller vessels, enter tissue
Chapter 18, Cardiovascular System
VEIN
Chapter 18, Cardiovascular System
- Carries blood that contains waste and CO2
- Exception pulmonary vein
- Blood not under much pressure
- Valves to prevent much gravity pull
Venules: larger than capillaries
CAPILLARIES
- Smallest vessel
- Microscopic
- Walls one cell thick
- Nutrients and gases diffuse here
