The Heart
1. The heart is a chambered muscular organ that pumps blood received from the veins into the arteries, there by maintaining the flow of blood through the entire circulatory system.
2. The heart is surrounded by membrane called Pericardium. Its functions is to restrict excessive movements of the heart as a whole and to serve as a lubricated container in which the different parts of the heart can contract.
Function of the heart
Systemic circulation
Video
Location of the heart.
•The
heart is located in the thoracic cavity between the to pleural cavities that
surround the lungs.
The Heart Chambers
Right and left side act as separate pumps four chambers;
1. two atrium (right and left)
2. two ventricles (right and left)
Right atrium ;-
Receives deoxygenated blood from the
inferior vena cava below and from the superior vena cava above.
• Receives the coronary
sinus
in
its lower part.• The upper end of the atrium projects to
the left of the superior vena cava as the right
auricle.
•The sulcus terminalis is a vertical groove on the outer surface of the atrium. This groove corresponds internally to the crista terminalis .•Above the coronary sinus the interatrial septum forms the posterior wall. The depression in the septum the fossa ovalis are presents the site of the foramen ovale.
•The sulcus terminalis is a vertical groove on the outer surface of the atrium. This groove corresponds internally to the crista terminalis .•Above the coronary sinus the interatrial septum forms the posterior wall. The depression in the septum the fossa ovalis are presents the site of the foramen ovale.
•The
sulcus
terminalis
is
a vertical groove on the outer surface of the atrium. This groove corresponds
internally to the crista
terminalis
.•Above
the coronary sinus the interatrial septum forms
the posterior wall. The depression in the septum the fossa
ovalis
are
presents the site of the foramen ovale.
Left atrium
•Receives oxygenated blood from four pulmonary veins which drain posteriorly.•The cavity is smooth walled except for the atrial appendage.•On the septal surface a depression marks the fossa ovalis.
•The mitral (bicuspid) valve guards the passage of blood from the left atrium to the left ventricle.
Right ventricles
•Receives blood from the right atrium through the tricuspid valve .
The edges of the valve cusps are attached to chordae tendineae which are, in turn, attached below to papillary muscles.
•The wall of the right ventricle is thicker than that of the atria but not as thick as that of the left ventricle.
•The wall contains a mass of muscular bundles known as trabeculae carneae.•The infundibulum is the smooth walled outflow tract of the right ventricle.
•The pulmonary valve is situated at the top of the infundibulum.
•It is composed of three semilunar cusps.
•Blood flows through the valve and into the pulmonary arteries via the pulmonary trunk to be oxygenated in the lungs.
Left ventricles
•The wall of the left ventricle is thicker than the right ventricle but the structure is similar.
•The thick wall is necessary to pump oxygenated blood at high pressure through the systemic circulation.
•Trabeculae carneae project from the wall with papillary muscles attached to the mitral valve cusp edges by way of chordae tendineae.
•The vestibule is a smooth walled part of the left ventricle which is located below the aortic valve .
•Receives oxygenated blood from four pulmonary veins which drain posteriorly.•The cavity is smooth walled except for the atrial appendage.•On the septal surface a depression marks the fossa ovalis.
•The mitral (bicuspid) valve guards the passage of blood from the left atrium to the left ventricle.
Right ventricles
•Receives blood from the right atrium through the tricuspid valve .
The edges of the valve cusps are attached to chordae tendineae which are, in turn, attached below to papillary muscles.
•The wall of the right ventricle is thicker than that of the atria but not as thick as that of the left ventricle.
•The wall contains a mass of muscular bundles known as trabeculae carneae.•The infundibulum is the smooth walled outflow tract of the right ventricle.
•The pulmonary valve is situated at the top of the infundibulum.
•It is composed of three semilunar cusps.
•Blood flows through the valve and into the pulmonary arteries via the pulmonary trunk to be oxygenated in the lungs.
Left ventricles
•The wall of the left ventricle is thicker than the right ventricle but the structure is similar.
•The thick wall is necessary to pump oxygenated blood at high pressure through the systemic circulation.
•Trabeculae carneae project from the wall with papillary muscles attached to the mitral valve cusp edges by way of chordae tendineae.
•The vestibule is a smooth walled part of the left ventricle which is located below the aortic valve .
Function of the heart
Major function of the heart are:-
a) Generating blood pressure.
Contractions of the heart generate blood pressure, which is required to force blood through the blood vessels.
b) Routing blood
The heart separates the pulmonary and systemic circulations, which ensures the flow of oxygen rich blood to tissues.
c) Ensuring one-way blood flow
The valves of the heart ensure a one-way flow of blood through the heart and blood vessels.
d) Regulating blood supply
Changes in the rate and force of heart contraction match blood flow to the changing metabolic needs of the tissues during rest, exercise, and change in the body position.
Circulatory system
Circulatory system
• HEART: atrium, ventricles
• BLOOD VESSELS: aorta, arteries, arterioles, capillaries, veinules, veins
Pulmonary circulation
The heart is actually two pumps in one. The right side of the heart pumps blood to the back to the left side of the heart through vessels - right ventricle to lungs to left atrium.
Systemic circulation
the left side of the heart pumps blood to all other tissues of the body and back to the right side of the heart through vessels
Main functions of blood flow
• to deliver oxygen and nutrients to the cells
• to remove cellular wastes and carbon dioxide
• to maintain organs at a constant temperature and pH
Heart attack
•Heart attack happened when the fat block the blood from flow in the blood cell by atherosclerosis or blood vessel was blocked by the fat
•Atherosclerosis is the process that fat and cholesterol are collected and combine together in the blood vessel and block the blood from flow to the heart.
Factors of the heart
1.Smoking
2.Cigarette smoking
3. Higher fat level
4. No more exercise
5. Alcohol
6. Blood pressure
7. Diabetes
Symptom
- left ventricle to aorta to organs and tissues to right atrium
Main functions of blood flow
• to deliver oxygen and nutrients to the cells
• to remove cellular wastes and carbon dioxide
• to maintain organs at a constant temperature and pH
•Heart attack happened when the fat block the blood from flow in the blood cell by atherosclerosis or blood vessel was blocked by the fat
•Atherosclerosis is the process that fat and cholesterol are collected and combine together in the blood vessel and block the blood from flow to the heart.
Factors of the heart
1.Smoking
2.Cigarette smoking
4. No more exercise
5. Alcohol
6. Blood pressure
7. Diabetes
Symptom
I. Breathless
II. Chest pain
III. Unconscious
IV. Sweaty although cold weather
V. Panic
Video