Chapter 17 -The Cardiovascular System I: The Heart
Module 17.1 Overview of the Heart
Functions of the Heart: to pump blood
Circulation of blood through the Pulmonary and Systemic Circuits
Right side of the heart:
Left side of the heart:
Module 17.2 Heart Anatomy and Blood Flow Pathway
The Pericardium, Heart Wall, and Heart Skeleton
Pericardium:
Fibrous pericardium:
Serous pericardium:
Parietal pericardium:
1
Visceral pericardium (epicardium):
Pericardial cavity:
Myocardium:
Endocardium:
Endothelium:
Coronary Circulation:
Coronary Arteries
Right and left coronary arteries:
Right coronary artery and branches supply blood to the right atrium and right
ventricle.
Left coronary artery and branches supply blood to the left atrium and left
ventricle
Coronary venous blood empties into the coronary sinus which drains into the
right atrium
2
The Great Vessels, Chambers, and Valves of the Heart
Great Vessels
Chambers
Valves
Blood flow through the heart (“Big Picture” fig 17.8)
3
Module 17.3 Cardiac Muscle Tissue Anatomy and Electrophysiology
Histology of Cardiac Muscle Tissue and Cells
-
Review the events along the cell membrane to cause a muscle contraction
At rest
contraction
end of contraction
return to rest
Pacemaker cells and the cardiac conduction system
The pacemaker cells have slow leaking sodium channels. When enough sodium leaks in, a
depolarization occurs. The depolarization spreads through the cardiac musculature. This is
followed by repolarization and return to rest. Pacemaker cells exhibit autorhymicity.
Anatomy of the Cardiac Conduction System
SA node
AV node
Purkinje fiber system
AV bundle
4
Bundle branches
Terminal branches of Purkinje fibers
Pacing the Heart: Sinus Rhythm
Conduction pathway through the heart
The Electrocardiogram
P wave
QRS complex
T wave
5
Module 17.4 Mechanical Physiology of the Heart: The Cardiac Cycle
Heart Sounds
Ventricle
Atrium
A/V valves
SL valves
Blood Pressure
Lub (S1)
systole
diastole
close
open
systolic
Dup (S2)
diastole
systole
open
closed
diastolic
Module 17.5 Cardiac Output and Regulation
Cardiac Output:
Heart Rate X Stroke Volume = Cardiac Output
Factors that influence stroke volume
Preload
Contractility
Afterload
6
Factors that influence Heart Rate
Regulation of Cardiac Output
Cardiac Innervation and Regulation by the Nervous System
Sympathetic regulation:
Parasympathetic regulation:
Cardiac Regulation by the Endocrine System
Other Factors that Influence Cardiac Output
7