Download The Heart - My Anatomy Mentor

CIRCULATORY SYSTEM: THE HEART
SIZE, LOCATION AND ORIENTATION
 Mediastinum 
 Base of the heart –
 Apex of the heart –
HEART COVERINGS
 Pericardium –
E
Fibrous Pericardium –
E
Serous Pericardium –
q
q
E
Visceral layer –
e
Also called the outer layer of the epicardium
e
Composed of fibroelastic tissue that merges with the heart muscle
Parietal layer –
Pericardial cavity –
HEART MUSCLE


 Composed of three layers:
E
Endocardium –
E
Myocardium –
E
Epicardium –
1
HEART CHAMBERS
 Four chambers separated by interatrial and interventricular septa or walls
E
E
E
E
Right Atrium –
q
Entrance of:
q
Auricles –
q
Fossa ovalis –
q
Pectinate muscles –
q
Tricuspid Valves –
Right Ventricle –
q
Exit of Pulmonary trunk –
q
Pulmonary semilunar valve –
q
Papillary muscles –
q
Chordae tendineae –
q
Trabeculae carneae –
q
Moderator band –
Left Atrium –
q
Entrance of Pulmonary veins –
q
Bicuspid (mitral) valve –
q
Pectinate muscles –
Left Ventricle –
q
Exit of aorta –
q
Aortic Semilunar valve –
q
Trabeculae carneae –
q
Chordae tendineae –
2
BLOOD PATHWAY THROUGH HEART
 Pulmonary Circulation –
 Systemic Circulation –
 Coronary Circulation
E
Two coronary arteries and their branches supply blood to the heart itself
E
Both arise from the base of the aorta and encircle the heart in the atrioventricular groove (coronary sulcus)
E
Effective when the heart is not contracting
E
Right Coronary Artery –
E
E
q
Marginal artery –
q
Posterior interventricular artery –
q
Sinoatrial nodal artery –
q
Atrioventricular nodal artery –
Left Coronary Artery –
q
Anterior interventricular artery –
q
Circumflex artery –
Coronary Veins –
q
Coronary sinus –
e
Three tributaries:
C Small, middle and great cardiac veins –
q
Anterior cardiac veins –
CARDIAC HISTOLOGY
 Cardiac Muscle –
E
Intercalated discs –
3
CARDIAC CONDUCTION SYSTEM
 Nodal System –
E
Autorhythmic cells –
q
q
q
q
q
 Sequence of Excitation –
E
Sinoatrial (SA) Node –
q
q
q
q
q
E
Atrioventricular (AV) Node –
q
q
q
E
Atrioventricular Bundle (Bundle of His) –
q
E
Bundle Branches –
q
q
E
Purkinje Fibers –
q
q
4
q
 Extrinsic Innervation –
E
E
E
E
Stimulation by sympathetic neurons –
q
q
E
Inhibition by parasympathetic neurons –
q
q
q
CARDIAC CYCLE
 Two Phases:
E
E
Systole Phase –
q
Atrial systole (0.1 sec) –
q
Ventricular systole (0.3 sec) –
Diastole Phase –
q
Ventricular diastole –
5
ELECTRICAL EVENTS (as recorded from an ECG)
 Consists of three waves:
E
P wave –
E
QRS complex –
E
T wave –
HEART SOUNDS
 Lub-dub –
 Pause –
CARDIAC OUTPUT –
 Starling’s Law of the Heart –
HEART RATE REGULATION
 Nervous Regulation –
E
Cardiac inhibitory center –
q
E
Vagus nerve –
Cardiac accelerator center –
 Hormonal Regulation
E
Accelerators –
6
 Body Temperature –
 Baroreceptors (pressoreceptors) –
E
Carotid sinus & Aortic arch –
E
Bainbridge (atrial) baroreceptors –
HEART AND CIRCULATORY DISORDERS
 Tachycardia –
 Bradycardia –
 Myocardial infarction –
 Arrhythmia –
 Fibrillation –
 Angina pectoris –
 Pericarditis –
 Congestive heart failure –
 Atherosclerosis –
 Ischemic heart disease –
 Heart murmur –
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