1. Physiologic Anatomy of the Heart; the central pump.pdf

Physiologic Anatomy of the Heart; the Central Pump of the Cardiovascular System Prof. Oluwadare Ogunlade Preventive Cardiologist and Cardiovascular Physiologist 1 18 April 2024  Learnin...

Physiologic Anatomy of the Heart; the Central Pump of the Cardiovascular System Prof. Oluwadare Ogunlade Preventive Cardiologist and Cardiovascular Physiologist 1 18 April 2024  Learning Objectives At the end of this lecture, the candidate should be able to; 1. Describe the anatomy of the heart and cardiovascular system 2. Describe the heart as a pump 3. Describe the major and minor circulatory circuits 4. State the functions of the components of the cardiovascular system 2 18 April 2024  History  William Harvey(English Physician,1578-1657 ) was the first to conclude that blood must circulate around and around.  William Harvey’s work published in 1628 is considered the beginning of modern physiology and cardiovascular research. 3 18 April 2024  Cardiovascular Physiology and its significance  Cardiovascular physiology is the study of the function of the cardiovascular system.  A sound knowledge of human cardiovascular physiology is essential as a solid foundation for the training of doctors, nurses, pharmacists, physiotherapists, physiologists, and other paramedics.  Cardiovascular physiology has a lot of potentials for entrepreneurship in clinical practice 4 18 April 2024  Cardiovascular System: The overview  The Cardiovascular System(CVS) consists of the heart and the network of blood vessels in which the blood circulates.  It is also referred to as the circulatory system.  In human beings, the CVS exists as a closed circuit in which the blood stays within the circuit as it circulates and chemicals or other substances in the system are exchanged by diffusion.  CVS in humans is a closed circulatory system. 5 18 April 2024 6 18 April 2024  The Heart  The human heart is a 4-chambered muscular organ located in the chest.  It is main pump(engine) of the cardiovascular system.  The chambers of the heart include; the right and left atria, and left and right ventricles.  It is covered by a pericardium of two layers  A thin film of pericardial fluid lubricates the heart. 7 18 April 2024  Heart and Great Vessels 8 18 April 2024  The Heart: Central Pump 9 18 April 2024  Components of the Heart  4 Chambers;  right atrium, left atrium, right ventricle, and left ventricle  4 Valves; mitral valve, tricuspid valve, pulmonary valve, and Aortic valve  4 Great vessels i. Superior vena cava ii. Inferior vena cava iii. Aorta iv. Pulmonary artery  4 Pulmonary veins: 10 18 April 2024  The Heart: Modulation-Autonomic nerves 11 18 April 2024  Vascular Network  The vascular network consists of the aorta, arteries, arterioles, capillaries, venules, veins and vena cavae.  The cardiovascular system has two main divisions; 1. Systemic circulation (major division) 2. Pulmonary circulation (minor division) 12 18 April 2024  The Circulatory System 13 18 April 2024  Systemic Circulation  Systemic circulation involves the transportation of blood and its constituents from the left side of the heart to the body tissues and back to the right side of the heart.  The systemic circulation is called the major circulation and it is a high-pressure driven system.  The pump for systemic circulation is the left ventricle.  The feeding venous system to the systemic circulation is the pulmonary venous system. 14 18 April 2024  Systemic Circulation left atrium→ left ventricle→ aorta→ arteries→ arterioles→ capillaries→ venules →veins→ vena cavae → right atrium 15 18 April 2024  Pulmonary Circulation  Pulmonary circulation involves the transportation of blood and its constituents from the right side of the heart to the lung and back to the left side of the heart.  It is a low-pressure driven system compared with systemic circulation.  The pump for pulmonary circulation is the right ventricle.  The feeding venous system to the pulmonary circulation is the systemic venous system. 16 18 April 2024  Pulmonary Circulation right atrium→ right ventricle→ pulmonary trunk→ pulmonary arteries→ lung capillaries→ pulmonary veins→ left atrium 17 18 April 2024  Functions of Cardiovascular System  The functions of the cardiovascular system can be categorised into two; 1. Mechanical function 2. Electrical function 18 18 April 2024  Mechanical Function  Cardiovascular system serves as a vehicle for the delivery of blood and its constituents across the body.  Cardiovascular system generates the blood pressure for transportation and redistribution of blood and its constituents 19 18 April 2024  Substances transported within the cardiovascular system  Blood cells e.g. erythrocytes and leucocytes  Gases such as oxygen and carbon dioxide  Food nutrients e.g. proteins, lipids, glucose, vitamins, and minerals  Fluid e.g. water  Electrolytes such as sodium and potassium  Hormones  Cytokines  Waste products e.g. urea  Energy and heat 20 18 April 2024  Electrical Function  The cardiovascular system generates and propagates the electrical impulses that give life to the body.  The electrical activity precedes mechanical activities.  Implying that excitation results in contraction. 21 18 April 2024  Functions of Components of Cardiovascular System COMPONENT FUNCTION Heart Central pump Generates and propagates the cardiac electrical impulses Arteries Transport blood under high pressure and maintain blood flow at high velocities Arterioles Maintain blood flow in response to tissue demand Capillaries Exchange water, gases, nutrients, hormones, cytokines and other substances between the vascular system and interstitium Venules Transport blood from capillaries into veins Veins Transport blood under low pressure from venules into the heart 22 Veins also serve as a controllable blood reservoir 18 April 2024