1. Chapter 18: Anatomy of the Cardiovascular System
Summary:
Anatomy of the Heart is:
4 chambers
4 valves
4 great vessels
3 layered covering
3 layered wall
3 circuits

2. The Heart is a muscular PUMP with 4 Chambers
(size and shape of a fist)
with 4 Chambers
The upper chambers ( R atrium, L atrium )
are for receiving Blood
The lower chambers (R Ventricle, L Ventricle)
are for pumping blood LA
Right Atrium Left Atrium
Right Ventricle Left Ventricle RA RV LV

4. Right and Left Atria separated by the membranous ATRIAL SEPTUM
Located in the MEDIASTINUM
of the THORACIC CAVITY,
between the Right and Left Lungs,
posterior to the body of STERNUM,
Anterior to Thoracic Vertebrae 5-8.
Sits atop the diaphragm
Right and Left Atria separated by the membranous ATRIAL SEPTUM
(valves separate RA/RV,
LA/LV)
Ventricles separated by the muscular
INTERVENTRICULAR SEPTUM RA LA RV LV

6. 4 CARDIAC VALVES important in regulating the filling & flowing
The Heart has 4 valves,
important in regulating the filling & flowing
of the chambers of the blood
TRICUSPID VALVE (Right Atrium / Right Ventricle)
MITRAL VALVE (Left Atrium / Left Ventricle)
PULMONIC VALVE (right Ventricle / Pulmonary trunk {artery} )
AORTIC VALVE (Left Ventricle / Aorta)

7. LA LV RV The Atrioventricular valves (tricuspid and mitral)
The Pulmonic and the Aortic Valves are semilunar valves,
Each with three billowy, pocket-like
leaflets
The Atrioventricular
valves
(tricuspid and mitral)
are composed of flat flaps (cusps),
are connected
to the interior
ventricular walls via
Connective tissue
chords -- (CHORDAE TENDONAE),
and
PAPILLARY MUSCLES.
Pulmonic
valve
Aortic valve LA RA
Mitral valve LV
Chordae
tendonae
Tricuspid
valve RV
Papillary
muscle
Chordae
tendonae

9. Auricles of Right and Left Atria
On both the Right & the Left Atrium,
there is an ear-like extension called the Auricle these are visible on the external surface of the heart:
Auricle of right atrium RA
Auricle of right atrium RV
Left ventricle
Apex of the heart

11. The HEART and GREAT VESSELS
Each of the 4 cardiac chambers is associated with Major Blood vessel/s: (entering or exiting)
Right Atrium : (in) Superior & Inferior Vena Cavae
Right ventricle: Pulmonary Trunk (R & L pulm. arteries)
(out)
Left Atrium: (in) Pulmonary veins
Left Ventricle: Aorta

12. R & L Pulmonary arteries Superior Vena Cava Aorta
Pulmonary Trunk:
R & L Pulmonary arteries
Superior Vena
Cava
Aorta
(Anterior view)
Pulmonary veins
Ventricles make up most of volume of heart.
The right ventricle forms most of the heart’s anterior surface.
The left ventricle forms most of the posterior/inferior surface.
Inferior
Vena Cava
(more on these to follow)
Note: red oxygenated, blue unoxygenated blood

13. vena cavae, aortic arch, pulmonary trunk, pulmonary veins
To remember great vessels: in order VC, AA, PT, PV

14. Heart: posterior view

16. Triple layered Covering of the heart: PERICARDIAL SAC Heart coverings protect against friction
Fibrous Pericardium: the thick, tough outer sac, which is lined
By the
Serous Pericardium: a thin, moist double membrane,
the parietal layer, which lines the fibrous pericardium, and
the visceral layer, which adheres to & covers the heart, it is also known as
THE EPICARDIUM

17. Serous pericardium (two-layered)
Coverings of the Heart
Fibrous pericardium
Serous pericardium (two-layered)
Parietal layer lines fibrous pericardium
Visceral layer (epicardium) forms outermost part of heart wall
Fibrous pericardium composed of dense connective tissue & functions to:
Protect the heart.
Anchor heart to surrounding structures.
Prevent overfilling of heart with blood.
Serous pericardium is a two-layered serous membrane (secretes serous fluid)
Pericarditis? Inflammation of the pericardium. Hinders production of serous fluid & roughens serous membrane surfaces. Over time may lead to adhesions that impede heart activity. In severe cases may cause cardiac tamponade.
Cardiac tamponade – heart is compressed by fluid (inflammatory fluid that seeps into the pericardial cavity). Treatment – drain off excess fluid.

18. 3 Layers of the heart wall
Epicardium: thin , moist - is the visceral pericardial membrane
MYOCARDIUM the Heart Muscle,
the left ventricular wall is three times as thick as the right ventricle
ENDOCARDIUM the inner lining, made up of single layer of ENDOTHELIUM,
( endothelium also lines the blood vessels of the entire CVS)

20. Ventricles ( FYI )
Two lower chambers known as pumping chambers because, upon contraction, they push blood into the large network of vessels
Ventricular myocardium is thicker than the atrial myocardium because great force must be generated to pump the blood a large distance, against systemic resistance. Myocardium of left ventricle is thicker than the right for same reasons – distance and increased resistance.

21. 2 3 CIRCUITS B. SYSTEMIC CIRCUIT: A. PULMONARY CIRCUIT:
Right heart: unoxygenated blood from SVC & IVC
Right Atrium >>> Right Ventricle>>> Pulmonary Trunk
Right and left Pulmonary arteries, into the LUNGS,
for gases exchange; then to Heart via Pulm veins
B. SYSTEMIC CIRCUIT:
Left heart: oxygenated blood from PULM Veins
Left atrium >>> Left Ventricle >>> Aorta , and
the systemic arterial, capillary, venous network
C. CORONARY CIRCULATION: blood flow to the heart

22. Right side of heart is pulmonary circuit pump
***Flow of Blood Through Heart***
Right side of heart is pulmonary circuit pump
Left side of heart is systemic circuit pump
right atrium (tricuspid valve) -> right ventricle (pulmonary SL valve) -> lungs -> left atrium (bicuspid (mitral) valve) -> left ventricle (aortic SL valve) -> body tissues
Pulmonary circuit – blood vessels that carry blood to and from the lungs.
Systemic circuit – blood vessels that carry blood to and from all body tissues.

23. Systemic & Pulmonary Circuits

24. Lung Bypasses in Fetal Heart
Foramen ovale – opening between right &left atria; after birth closes to form fossa ovalis.
Ductus arteriosus – connection between pulmonary trunk & aorta; closes to form ligamentum arteriosum.
These 2 shunts allow blood to bypass the deflated, nonfunctional lungs.
Foramen ovale & ductus arteriosus close at or shortly after birth.

25. CORONARY ARTERIES: BLOOD SUPPLY TO THE HEART
THE FIRST BRANCHES off the AORTA,
immediately superior to the Aortic valve:
RIGHT CORONARY ARTERY,
LEFT MAINSTEM CORONARY ARTERY,
with its 2 quick branches: LEFT CIRCUMFLEX,
LEFT ANTERIOR DESCENDING.
Coronary blood flow actually occurs when the aortic valve cusps are closed, during back-flow; not during the powerful “systolic” pulsation of blood out of the ventricle during contraction.

26. (systole)
(diastole)

27. CORONARY VEINS Veins of the coronary circulation
As a rule, veins follow a course that closely parallels that of coronary arteries.
After going through cardiac veins, blood enters the CORONARY SINUS to drain into the right atrium
Several veins drain directly into the right atrium

28. posterior
anterior

29. posterior