The Circulatory System
description
Transcript of The Circulatory System
![Page 1: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/1.jpg)
The Circulatory System
![Page 2: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/2.jpg)
Circulatory System
• The Circulatory System has two major subdivisions:
1. The cardiovascular system: The heart
2. The lymphatic system: Pumpless system of vessels and lymphoid organs that aids the cardiovascular system
![Page 3: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/3.jpg)
Cardiovascular System
![Page 4: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/4.jpg)
Location and Size• Location and size:- Approximately the size
of a person’s fist, the hollow, cone-shaped heart weighs less than a pound
- The heart is located within the bony thorax and is in between the lungs
![Page 5: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/5.jpg)
Location and Size• Location :- Its more pointed apex is
directly toward the left hip and rests on the diaphragm, approximately at the level of the fifth intercostal space
- Its base, from which the great vessels of the body emerge, points toward the right shoulder and lies beneath the second rib
![Page 6: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/6.jpg)
Coverings and wall• The heart is enclosed by a
double sac of membrane, the pericardium:
- The thin visceral pericardium, or epicardium, tightly hugs the external surface of the heart and is actually part of the heart wall
- The fibrous layer, parietal pericardium, helps protect the heart and anchors it to surrounding structures, such as the diaphragm and the sternum
![Page 7: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/7.jpg)
Coverings and wall• A slippery lubricating fluid
is produced by the pericardial membranes:
- This fluid allows the heart to beat easily in a relatively frictionless environment as the pericardial layers slide smoothly across each other
![Page 8: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/8.jpg)
Pericarditis• Inflammation of the
pericardium, often results in a decrease in the amount of fluid
• This causes the pericardial layers to bind and stick to each other, forming painful adhesions that interfere with heart movements
![Page 9: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/9.jpg)
Heart Wall - Myocardium• The heart walls are composed of
three layers:- The outer epicardium, the
myocardium, and the innermost endocardium
• The myocardium consists of thick bundles of cardiac muscle twisted and whorled into ring like arrangement
- It is the layer that actually contracts- It is reinforced internally by a dense,
fibrous connective tissue network called the “ skeleton of the heart”
![Page 10: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/10.jpg)
Heart Wall - Endocardium
• The endocardium is a thin, glistening sheet of endothelium that lines the heart chambers
• It is continuous with the linings of the blood vessels leaving and entering the heart
![Page 11: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/11.jpg)
Lungs
Body cells
Our circulatory system is a double circulatory system.
This means it has two parts parts.
the right side of the system: carries
deoxygenated blood away from the heart, to the
lungs, and returns oxygenated blood back to the heart
the left side of the system: carries
oxygenated blood away from the
heart to the body, and returns
deoxygenated blood back to the
heart
Pulmonary Circulation:
Systemic Circulation
![Page 12: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/12.jpg)
![Page 13: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/13.jpg)
Aorta
right pulmonary artery
Left pulmonary artery
Right atriumLeft atrium
Right ventricle
Left ventricle
Superior VenaCava
Inferior VenaCava
Interventricular septum
right pulmonary veins
Left pulmonary veins
Tricuspid valve
Pulmonary semilunar
valve
Aortic semilunar
valveBicuspid valve
![Page 14: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/14.jpg)
Valves – AV valves• The atrioventricular or AV valves
are located between the atrial and ventricular chambers on each side
• The AV valves prevent backflow into the atria when the ventricles contract
• The left AV valve- Bicuspid (mitral) valve: consist of 2
cusps, or flaps, of endocardium• The right AV valve- Tricuspid valve: has 3 cusps• Tiny white cords, the chordae
tendineae (heart strings), anchor the cusps to the walls of the ventricles
![Page 15: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/15.jpg)
Valves – semilunar valves• The semilunar valves guards the bases
of the two large arteries leaving the ventricular chambers
• Thus, they are known as the pulmonary and aortic semilunar valves
• Each semilunar valve has 3 cusps that fit tightly together when the valves are closed
• When the ventricles are contracting and forcing blood out of the heart, the cusps are forced open and flattened against the walls of the arteries
![Page 16: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/16.jpg)
Stage 1Blood enters the heart through a vein known as the vena cava. The blood is low in oxygen. The first chamber it goes into is the right atrium.
Stage 2The heart pumps the blood from the right atrium into the right ventricle.
Stage 3The heart pumps the blood from the right ventricle through the pulmonary artery towards the lungs.
Stage 4The blood returns from the lungs with lots of oxygen and re-enters the heart through the left atrium.
Stage 5The heart pumps the blood from the left atrium into the left
Stage 6The heart then pumps the blood from the left ventricle out of the heart to the rest of the body through the aorta.
![Page 17: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/17.jpg)
Cardiac Circulation• In reality, blood enters and exits both sides of
the heart at the same time.
blood from the body
blood from the lungs
The heart beat begins when the
heart muscles relax and blood
flows into the atria.
![Page 18: The Circulatory System](https://reader035.fdocuments.us/reader035/viewer/2022062814/568166f1550346895ddb4fbb/html5/thumbnails/18.jpg)
• The atria then contract and
the valves open to allow
blood
into the ventricles.• The valves close to stop blood flowing backwards.
• The ventricles contract forcing the blood to leave the heart.
• At the same time, the atria are relaxing and once again filling with blood.