1. The Cardiovascular System11
The Cardiovascular System

2. The Cardiovascular System
Cardio = realting to the ________?
Vascular = relating to the ____________?
CV System includes the heart, blood vessels, and about 5 liters of blood (5 liters ~ 1.3 gallons)
At a resting rate the heart is able to pumps 5 liters of blood throughout the entire body every minute.

3. Functions of the Cardiovascular System
Transportation – of oxygen, nutrients, hormones, and cellular waste
Protection – blood contains white blood cells and platelets
Regulation – maintain body temperature by controlling blood flow to the skin

4. The Heart Location Orientation About the size of your fist
Thorax between the lungs in the inferior mediastinum
Orientation
Pointed apex directed toward left hip
Base points toward right shoulder
About the size of your fist
Weighs less than a pound
Thorax – between neck and abdomen

5. Midsternal line 2nd rib Sternum Diaphragm (a)
(base of heart)
Sternum
Diaphragm
Point of
maximal
intensity
(PMI)
(a)
Figure 11.1a

6. Mediastinum Heart Left lung Posterior
MEDIASINUM - the central compartment of the thoracic cavity surrounded by loose connective tissue, contains a group of structures within the thorax. The mediastinum contains the heart and its vessels, the esophagus, trachea, phrenic and cardiac nerves, the thoracic duct, thymus and lymph nodes of the central chest.
Figure 11.1b

7. Aorta Left lung Diaphragm (c)
Superior
vena cava
Aorta
Parietal
pleura (cut)
Pulmonary
trunk
Left lung
Pericardium
(cut)
Apex of
heart
Diaphragm
(c)
Figure 11.1c

8. Brachiocephalic trunk Left common carotid artery
Superior vena cava
Left subclavian artery
Right pulmonary artery
Aortic arch
Ligamentum arteriosum
Ascending aorta
Left pulmonary artery
Pulmonary trunk
Left pulmonary veins
Right pulmonary
veins
Left atrium
Auricle of left atrium
Right atrium
Circumflex artery
Right coronary artery
in coronary sulcus (right
atrioventricular groove)
Left coronary artery in
coronary sulcus (left
atrioventricular groove)
Anterior cardiac vein
Left ventricle
Right ventricle
Great cardiac vein
Marginal artery
Anterior interventricular
artery (in anterior
interventricular sulcus)
Small cardiac vein
Inferior vena cava
Apex
(a)
Figure 11.3a

9. The Heart: Coverings
Pericardium—a double-walled sac that encloses the heart
Fibrous pericardium connects heart to the diaphragm and sternum
Serous membrane is deep to the fibrous pericardium and composed of two layers
Visceral pericardium
Next to heart; also known as the epicardium
Parietal pericardium
Outside layer that lines the inner surface of the fibrous pericardium
Serous fluid fills the space between the layers of pericardium

10. The Heart: Heart Wall Three layers Epicardium Myocardium Endocardium
Outside layer
This layer is the visceral pericardium
Connective tissue layer
Myocardium
Middle layer
Mostly cardiac muscle
Endocardium
Inner layer

11. Right pulmonary artery Left atrium
Superior vena cava
Aorta
Left pulmonary artery
Right pulmonary artery
Left atrium
Right atrium
Left pulmonary veins
Right pulmonary
veins
Pulmonary semilunar valve
Left atrioventricular valve
(bicuspid valve)
Fossa ovalis
Aortic semilunar valve
Right atrioventricular
valve (tricuspid valve)
Left ventricle
Right ventricle
Chordae tendineae
Interventricular septum
Inferior vena cava
Myocardium
Visceral pericardium
(b) Frontal section showing interior chambers and valves.
Figure 11.3b

12. The Heart: Chambers Right and left side act as separate pumps
Four chambers
Two Atria
Blood receiving chambers
Right atrium
Left atrium
Two Ventricles
Blood discharging chambers
Right ventricle
Left ventricle

13. Left ventricle Right ventricle Muscular interventricular septum
Figure 11.5

14. The Heart’s Role in Blood Circulation
Pulmonary circulation (Right side of heart)
Carries deoxygenated (oxygen-lacking) blood away from the heart, to the lungs, and returns oxygenated (oxygen-rich) blood back to the heart.
Systemic circulation (Left side of heart)
Carries oxygenated blood away from the heart to the body, and returns deoxygenated blood back to the heart.

15. Arteries vs. Veins
Arteries  carry blood away from the heart Veins  carry blood to the heart

16. Pulmonary Circulation
Superior Vena Cava (vein) – takes deoxygenated blood from the head, neck, and arms to right atrium
Inferior Vena Cava (vein) – takes deoxygenated blood from the lower body to right atrium
Right ventricle receives blood from the atrium
Pulmonary artery – carries deoxygenated blood from the right ventricle to the lungs

17. Systemic Circulation
Pulmonary Vein – carries oxygenated blood from lungs to the left atrium
From the left atrium the blood is pumped into the left ventricle
Aorta (artery) – carries oxygenated blood from the left ventricle to the entire body

18. The Heart: Valves
Allow blood to flow in only one direction to prevent backflow
Four valves
Atrioventricular (AV) valves—between atria and ventricles
Tricuspid valve (right side of heart)
Bicuspid (mitral) valve (left side of heart)
Open during heart relaxation and closed during ventricular contraction
Semilunar valves—between ventricle and artery
Pulmonary semilunar valve
Aortic semilunar valve
Closed during heart relaxation but open during ventricular contraction

19. Notice these valves operate opposite of one another to force a one-way path of blood through the heart

20. Valve Support Papillary Muscles Chordae Tendineae
located in the ventricles of the heart
attach to the cusps of the atrioventricular valves via the chordae tendineae
prevent inversion or prolapse of these valves
Chordae Tendineae
cord-like tendons that connect the papillary muscles to the AV valves in the heart

21. AV valves close. Ventricles
(a) Operation of the AV valves
Blood returning
to the atria puts
pressure against
AV valves; the AV
valves are forced
open. 1
Ventricles contract,
forcing blood against
AV valve flaps. 4 5
AV valves close.
As the ventricles
fill, AV valve flaps
hang limply into
ventricles. 2
Chordae
tendineae tighten,
preventing valve
flaps from everting
into atria. 6
Atria contract,
forcing additional blood into ventricles. 3
Ventricles
AV valves open;
atrial pressure
greater than
ventricular pressure
AV valves closed;
atrial pressure
less than
ventricular pressure
Figure 11.6a, step 6

22. (b) Operation of the semilunar valves
Pulmonary
trunk
Aorta
As ventricles
contract and
intraventricular
pressure rises,
blood is pushed up
against semilunar
valves, forcing
them open. 1
As ventricles
relax and
intraventricular
pressure falls,
blood flows
back from arteries,
filling the leaflets
of semilunar
valves and forcing
them to close. 2
Semilunar valves open
Semilunar valves closed
Figure 11.6b, step 2

23. Blood Flow Through the Heart
Superior and inferior venae cavae dump deoxygenated blood from the body into the right atrium
From right atrium, through the tricuspid valve, blood travels to the right ventricle
From the right ventricle, blood leaves the heart via the pulmonary semilunar valve into the pulmonary artery
The pulmonary artery carries blood to the lungs

24. Blood Flow Through the Heart
In the lungs oxygen is picked up and carbon dioxide is dropped off
Oxygen-rich blood returns to the heart through the four pulmonary veins
The pulmonary veins dump blood into the left atrium
The blood is pumped through the bicuspid valve into the
left ventricle
From the left ventricle, blood leaves the heart via the
aortic semilunar valve to the aorta and then the aorta carries blood throughout the body

25. The Heart: Cardiac Cycle
The cardiac cycle refers to a complete heartbeat
From its generation to the beginning of the next beat
So includes the diastole and systole of all four chambers
Systole = contraction
Diastole = relaxation
The frequency of the cardiac cycle is described by the heart rate (beats per minute - BPM)
Atria relax, when ventricles contract
Ventricles relax, when atria contract

26. The Heart: Heart Sounds
The first heart tone, "Lub“, is caused by the closure of the mitral and tricuspid valves
Ventricles are contracted (systole)
Atria are relaxed (diastole)
The second heart tone, "Dub“, is caused by the closure of the aortic valve and pulmonic valve 
Ventricles diastole
Atria systole