Download Heart Anatomy

CARDIOVASCULAR SYSTEM
Heart Anatomy
General
Closed System
- Blood Remains in Blood Vessels & Heart
Double System
- Four Chambers (Separation of Oxygenated
& Deoxygenated Blood)
- Heart is Double Organ:
* Pulmonary Circuit (Heart  Lungs  Heart)
* Systemic Circuit (Heart Body Tissues 
Heart)
Heart – Size & Location
Size: Adult Clenched Fist
Position: Mediastinum, 2/3 to Left of
Midline
Relationships to Other Organs:
- Medial to Lungs
- Superior to Diaphragm
- Anterior to Esophagus, Descending Aorta
Heart - Chambers
Atria (2)
- Superior Receiving Chambers (From Veins)
- Auricles (ear-like flaps)
- Right Atrium:
* O2 Poor Blood From Venae Cavae & Coronary
Sinus (Systemic Circ.)
- Left Atrium:
* O2 Rich Blood From Pulmonary Veins of Lungs
Heart – Chambers continued
Ventricles (2)
- Inferior Pumping Chambers (to Arteries)
- Receive from Atria
- Right Ventricle:
* O2 Poor Blood from Rt Atrium to Pulmonary
Arteries (Pulmonary Circ.)
- Left Ventricle:
* O2 Rich Blood from Left Atrium to Aorta
(Systemic Circ.)
Heart - Valves
One-Way, Direct Blood Flow
Passive; blood pushes them closed
2 Pairs:
- Atrioventricular (Cuspid) Valves
*Between Atria & Ventricles
Tricuspid (Right)
Bicuspid (left)
Atrioventricular Valves cont.
* AV Valves are anchored to structures in
the ventricles:
 Chordae Tendineae
Strong, Fibrous Strings
Prevent Cusp Eversion
 Papillary Muscle
Conical Extensions of
Myocardium in Ventricles
Contract & pull on chordae
tendinae
AV (MITRAL) VALVES
Cusps
OPEN
CLOSED
Heart - Valves
- Semilunar Valves
*Between Ventricles & Arteries
*Prevent blood from back flow into
ventricles
Pulmonary Semilunar Valve
(Right)
Aortic Semilunar Valve (Left)
SEMILUNAR VALVES
Cusps
OPEN
CLOSED
Heart - Wall
 3 Layers:
- Endocardium (Inner)
* Endothelium
* Lines Chambers, Valves, Septa, Blood
Vessels
- Myocardium (Middle)
* Thickest Layer (Esp. in Left Ventricle!)
* Cardiac Muscle Tissue
* Inherent Rhythmicity
* Trabeculae Carnae – Ridges, Folds &
Bridges of Ventricular Myocardium
Heart – Wall continued
- Epicardium (Outer)
*Visceral Pericardium
*Serous Membrane
*Thin, Fibrous, Transparent
Heart - Septa
Internal Walls
Separate Chambers
2 Septa:
- Interatrial Septum (Between the Atria)
- Interventricular Septum (Between the
Ventricles)
Heart – Pericardial Sac
 Parietal Pericardium
- Encloses Heart & Bases of Great Vessels
- Composed of :
* Inner Serous Coat/Serous Pericardium
Parietal & Visceral Pericardium
Both Secrete Lubricating Pericardial
Fluid into
Pericardial Cavity (Space Between
Serous Layers)
Heart – Pericardial Sac
continued
* Outer Fibrous Coat
Tough, Protective
Reinforces Serous Coat