The cardiovascular system consists of the heart and blood vessels (arteries, capillaries and veins.)
• Supplies oxygen and nutrients to tissues, removes wastes
• Pulmonary circuit carries deoxygenated blood to the lungs to release CO2 and pick up O2
• Systemic circuit sends oxygenated blood to cells of the body and picks up CO2 from cells.
The Cardiovascular System
Deoxygenated blood
Oxygenated blood
Oxygenatedblood pumped toall body tissuesvia aorta
Deoxygenatedblood pumpedto lungs viapulmonary arteries
Deoxygenated blood returnsto heart via venae cavae
Oxygenated blood returnsto heart via pulmonary veins
Left atrium
Left ventricleRight atrium
Right ventricle
The systemic circuit delivers oxygen to allbody cells and carries away wastes.
CO2
CO2CO2
CO2
O2O2
O2
O2
The pulmonary circuit eliminates carbondioxide via the lungs and oxygenates theblood.
CO2
CO2
O2
O2
O2
O2
CO2
CO2
Alveolus
• Pericardium is a dense fibrous connective tissue covering the heart ( sac around the heart)
• 3 distinct layers underneath pericardium– epicardium-contains coronary arteries and vessels
that nourish the heart– myocardium- contains heart muscle tissue– endocardium-contains Purkinge fibers that innervate
the heart
The Heart
Endocardium
Myocardium
Epicardium(visceral pericardium)
Coronaryblood vessel
PericardialcavityParietalpericardium
Fibrouspericardium
Chambers of the Heart
• 4 chambers– 2 thin walled atria that receive blood from the body
• Right atrium receives deoxygenated blood from the body
• Left atrium receives oxygenated blood from the lungs
– 2 thick walled ventricles that pump blood to the body• Right ventricle pumps deoxygenated blood to the
lungs • Left ventricle pumps oxygenated blood to the body
Superiorvena cava
Systemiccapillaries
Tissue cells
Systemiccapillaries
Tissue cells
Pulmonaryartery
Pulmonaryveins
Alveolus
Alveolus
Left atrium
Mitral valve
Aortic valve
Left ventricle
Right atrium
Tricuspid valvePulmonary valve
Inferior vena cava
Right ventricle
Aorta
Alveolarcapillaries
Alveolarcapillaries
O2
CO2
O2
O2
CO2
CO2
O2CO2
Right auricle
Right atrium
Right ventricle
Pericardial cavity
Left ventricle
Heart (covered byvisceral pericardium)
Pulmonary trunk
Left auricle
Cut edge ofparietal pericardium
Cut edge offibrous pericardium
Aorta
Right lung Left lung
Diaphragm
Superiorvena cava
Valves
• Pulmonary Valve -prevents backflow of blood into the right ventricle as blood is pumped to lungs
• Aortic valve -prevents backflow of blood into the left ventricle
• Right Atrioventricular valve (AV) (tricuspid)-prevents backflow of blood into the right atrium from the ventricle
• Left Atrioventricular valve (bicuspid or mitral valve)-prevents backflow of blood into the left atrium from the ventricle
VisibleBody
(a)
Aorta
Pulmonary trunk
Left pulmonary artery
Left pulmonary veins
Left auricleLeft coronary artery
Great cardiac veinAnterior interventricular artery(left anterior descending artery)
Left ventricle
Apex of the heart
Right coronaryartery
Superior vena cava
Right pulmonaryartery
Right auricle
Inferior vena cava
Small cardiac vein
Anterior cardiac vein
Right ventricle
Right pulmonaryveins
Anterior View of Heart
Fig13.09b
Left pulmonaryveins
Left pulmonary artery
Aorta
Left auricle
Circumflex artery
Cardiac vein
Left ventricle
Apex of the heart
Superior vena cava
Right pulmonaryartery
Right pulmonary veins
Left atrium
Right atrium
Inferior vena cava
Coronary sinus
Middle cardiac vein
Posterior interventricularartery
Right ventricle
(b)
Posterior View of Heart
Systole/Diastole
11
• Atrial Systole- contracting atria, relaxing ventricles.
• Ventricular systole –contracting ventricles, relaxing atria
• Diastole- when the entire heart is relaxing
12
The Cardiac Cycle
Pulmonaryvalve closed
Tricuspidand mitralvalves open
(a) (b)
Aorticvalve closed
Atrial systoleLA
LV
RV
RA
Ventriculardiastole
Pulmonaryvalve open
Tricuspidand mitralvalves closed
Aorticvalve open
Atrial diastole
Ventricularsystole
Valves and Contractions of the Heart
• Due to vibrations in heart tissues as blood rapidly changes velocity within the heart.
• Heart sounds can be described as a "lubb-dupp" sound.
• First sound (lubb) -ventricles contract and A-V valves are closing
• Second sound (dupp)-ventricles relax and aortic and pulmonary valves are closing.
Heart Sounds
• An electrocardiogram (ECG) is a recording of the electrical changes that occur during a cardiac cycle.
Electrocardiogram
(a)
(b)
0
–.5
.5
1.0
Milliseconds
0 200 400 600
S
Q
PT
R
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Mill
ivol
ts
Electorcardiogram
• Blood pressure -force of blood against inner walls of blood vessels anywhere in the cardiovascular system. – As blood gets further and further from the left ventricle, blood
pressure decreases.
• Pulse-The surge of blood that occurs with ventricular contraction and can be felt at certain points in the body.– Caused by the expansion and contraction of blood vessels
• Systolic pressure- During ventricular contraction, arterial pressure is at its highest.
• Diastolic pressure- When ventricles are relaxing, arterial pressure is at its lowest.
Blood Pressure
Normal blood Pressure= 120/80 or less
Taking Blood Pressure
• Subject is seated and relaxed.• Wrap the fabric cuff around the upper arm• Locate the brachial artery • Place the diaphragm of the stethoscope over the
brachial artery so that you can hear Kortokoff sounds
19
• Close the valve and pump air until the pressure reads 180mmHg.
• Open the valve of the bulb slowly until the pressure in the cuff drops at a rate of about 2 or 3 mm Hg per second.
• Listen for the sounds from the brachial artery-1st loud tapping sound=systolic pressure.
• When sounds suddenly are muffled= diastolic pressure.
20
Taking Blood Pressure
Top Related