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Cardiovascular system Cardiovascular system is the system of heart and blood vessels that circulate blood throughout the body.The blood circulating in the body transports nutrients and oxygen to all the tissues and removes carbon dioxide and waste products from the tissues.Heart is the central pump and the blood vessels are the series of the distributing and collecting tubes
Heart • Heart is a muscular organ that pumps blood throughout the circulatory system.it is situated in between the two lungs in the medial mediastinum.it is made up of four chambers—two atria and two ventricles. The musculature is more and thick in the ventricles than in the atria.the force of contraction of the heart depends upon the muscles
ACTIONS OF THE HEART • 1-Chronotropic action. • 2-Ionotropic action. • 3-Dromotropic action. • 4-Bathmotropic action.
1-Chronotropic action Chronotropic action is the frequency of heart beat or heart rate.it is of two types 1.Tachyrardia or increase in heart rate. 2.Bradycardia or decrease in the heart rate. EXPLANATION:
2.INOTROPIC ACTION • Force of contraction of heart is called inotropic action. • It is of two types • 1.Positive inotropic action or increase in the force of contraction. • 2.Negative inotropic action or decrease in the force of contration.
3.DROMOTROPIC ACTION • Dromotropic action is the conduction of impulse through heart.it is of two types • 1.Positive dromotropic action or increase in the velocity of conduction. • 2.Negative dromotropic action or decrease in the velocity of conduction.
4.BATHMOTROPIC ACTION • Bathmotropic action is the excitability of cardiac muscle.it is also of two types • 1.Positive bathmotropic action or increase in the excitability of cardiac muscle. • 2.Negative bathmotropic action or the decrease in the excitability of cardiac muscle.
Other actions of the heart • 1.Generating blood pressure. • Contractions of the heart generate blood pressure which is responsible for blood moment through the blood vessels. • 2.Routing blood:The heart separates the pulmonary and systemic circulations which ensures the flow of oxygenated blood to tissues. • .
3.Ensuring one-way blood flow.The valves of the heart ensure a one-way flow of blood through the heart and blood vessels. • 4.Regulating blood supply.Changes in the rate and force of heart contraction match blood delivery to the changing metabolic needs of the tissues,such as during rest,exercise and changes in body position
BLOOD VESSELS • The vessels of circulatory system are the aorta,arteries,arterioles,capillaries,venules,veins and vena cava.There are structural differences between different blood vessels.That is veins and arteries.
The thinnest blood vessels are in the form of extensive thin walled vascular channels called capillaries through which interchange between cardiovascular system and tissues occurs.the cardiovascular system constitutes one of the major coordinating and integrating systems of the human body.the other two systems with such actions are nervous system and endocrine system.
Blood vessels are divided structuraly and functionaly into two groups. • 1.Arterial system. • 2.Venious system.
Arterial system • The arterial system comprises the aorta,artries and arteriols. • Physiology:the arterial system carries the oxygenated blood from the heart to all tissues of the body.
VENOUS SYSTEM • From the capillaries venous system starts and it includes the venules,veins and vena cava. • The capillaries end in the venules. • The venules are smaller vessels.with thin muscular wall than the arterioles. • Physiology:venous system carries deoxygenated blood back to the heart from all tissues of the body.