Cardiovascular System unit 3 Nutrition..updatedpptx.pptx

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1. Cardiovascular System Musawir Hussain Lecturer KMU A&P-I Unit VIII

2. Objectives At the end of this session, the students will be able to: Define Heart and it functions Define blood vessels and list its functions Show electrical activity of heart define mechanical events of heart Show Cardic output and its control

3. Parts of the Circulatory System Divided into three major parts: Heart Blood Blood Vessels

4. Functions of C-V System Circulate blood throughout entire body for Transport of oxygen to cells. Transport of CO 2 away from cells. Transport of nutrients to cells. Movement of immune system components. (cells, antibodies ) Transport of endocrine gland secretions .

5. Heart Location: mediastinum and rests on the diaphragm . Size: as much as one’s close fist. Weight : 250 g in adult female and 300 g in male . Structure: Cone shaped with pointed apex inferiorly to left and broad base superiorly to the right . Membranous Layers Two Pericardiums as superficial fibrous pericardium of connective tissue and deeper serous pericardium of epithelial tissue connected with the fibrous pericardium. Serous pericardium —Parietal and visceral membrane. Pericardial cavity with pericardial fluid.

6. Right Side of the Heart Right atrium is a thin walled and low pressure chamber It has sinoatrial (SA) and atrioventricular (AV ) node It receives venous blood via two large veins i.e. Superior and inferior vena cava It communicate with right ventricle through tricuspid valve Walls of right ventricle is thick and receives blood from right atrium From the right ventricle, pulmonary trunk carries the venous blood to lungs In the lungs, the deoxygenated blood become oxygenated

7. Left Side Of The Heart Left atrium is a thin walled and low pressure chamber It receives oxygenated blood from the lungs through four pulmonary veins Blood from left atrium enters the left ventricle through mitral valve Wall of the left ventricle is very thick Left ventricle pumps blood to different parts of the body through systemic aorta

8. Septa Of the Heart Right and left atria are separated by a fibrous septum called interatrial septum Right and left ventricles are separated from one another by interventricular septum The upper part of this septum is a membranous, whereas the lower part is muscular in nature

9. Layers of heart —three layers Epicardium or visceral layer Myocardium—muscular layer Endocardium—endothelial layer

10. Pericardium is made up of two layers Outer parietal pericardium Inner visceral pericardium/ epicardium The space between the two layers is called pericardial cavity or space and contains a thin film of fluid

11. MyoCardium It is formed by cardiac muscle fibers or cardiac myocytes Myocardium forms the bulk of the heart and it is responsible for pumping Myocardium has three types of muscle fibers Muscle fibers which form contractile unit of heart Muscle fibers which form pacemaker Muscle fibers which form conductive system

12. Myocardium These are striated and resemble the skeletal muscle in structure But, it is branched It is bound by sarcolemma having central nucleus Sarcomere have all the contractile proteins Neighboring fibers are fused by a tough double membranous structure, that form junction called intercalated disk At the sides, the membranes of the adjacent muscle fibers fuse together to form gap junctions

13. Serous membrane Continuous with blood vessels

14. Valves Your heart has four valves. They act like gates, keeping the blood moving in the right direction: aortic valve - on the left side mitral valve - on the left side pulmonary valve - on the right side tricuspid valve - on the right side

15. Valves permit the flow of blood in only one direction Two atrioventricular valves Bicuspid valve Tricuspid valve Cusps of the valves are attached to papillary muscles by means of chordae tendineae Two semilunar valves Aortic valve Pulmonary valve Semilunar valves are made up of three flaps

16. Blood vessels Your blood is pumped around your body through a network of blood vessels: arteries - they carry oxygen-rich blood from your heart to all parts of your body, getting smaller as they get further away from the heart capillaries - they connect the smallest arteries to the smallest veins, and help exchange water, oxygen, carbon dioxide and other nutrients and waste substances between the blood and the tissues around them veins - they carry blood, lacking in oxygen, back towards your heart, and get bigger as they get nearer your heart Blood vessels are able to widen or narrow depending on how much blood each part of your body requires. This action is partly controlled by hormones.

17. Vessels are: Aorta Vessels are: Aorta Arteries Arterioles Capillaries Venules Veins Venae cavae Arteries Arterioles Capillaries Venules Veins Venae cavae

18. Walls of the arterial system are formed by three layers: Artrial System Walls of the arterial system are formed by three layers: Outer tunica adventitia- connective tissue layer Middle tunica media- smooth muscles Inner tunica intima- endothelium It have two laminae of elastic tissues: External elastic lamina- adventitia and media Internal elastic lamina- media and intima Aorta and arteries have more elastic tissues and the arterioles have more smooth muscles Outer tunica adventitia- connective tissue layer Middle tunica media- smooth muscles Inner tunica intima- endothelium It have two laminae of elastic tissues: External elastic lamina- adventitia and media Internal elastic lamina- media and intima Aorta and arteries have more elastic tissues and the arterioles have more smooth muscles

19. Arterial branches become narrower and walls become thinner while reaching the periphery as: Aorti CoC Cont.... Arterial branches become narrower and walls become thinner while reaching the periphery as: Aortic diameter = 25 mm Diameter of end arteries = 4 mm Diameter of ends arterioles = 10 µ Resistance is offered to blood flow in the arterioles and are called resistant vessels Arterioles are continued as capillaries, which are small, thin walled having a diameter of about 5 to 8 µ The exchange of materials between the blood and the tissues occurs through capillaries c diameter = 25 mm Diameter of end arteries = 4 mm Diameter of ends arterioles = 10 µ Resistance is offered to blood flow in the arterioles and are called resistant vessels Arterioles are continued as capillaries, which are small, thin walled having a diameter of about 5 to 8 µ The exchange of materials between the blood and the tissues occurs through capillaries

20. Venous Systm; From the capillaries, venous system starts as it end on venules Venules are smaller and thinner than the arterioles At a time, a large quantity of blood is held in venules and are called capacitance vessels Venules are continued as veins, that form venae cavae The elastic tissue is less but the smooth muscle fibers are more

21. 29 3 Major types of blood vessels Body RA RV Lungs LA LV Boby Arteries Capillaries Veins Arteries carry blood away from the heart -”branch,” “diverge” or “fork” Veins carry blood toward the heart -”join”, “merge,” “converge”

22. 30 Capillaries Heart to arteries to capillaries to veins to heart Capillaries are smallest 8-10um Just big enough for single file erythrocytes Composed of: single layer of endothelial cells surrounded by basement membrane Universal function Oxygen and nutrient delivery to tissues CO2 and nitrogenous waste removal

23. Chambers of the heart; valves

24. Electrical system For your heart to keep pumping regularly, it needs electrical signals which are sent to the heart muscle telling it when to contract and relax. The electrical signal starts in the right atrium where your heart’s natural pacemaker - the sino–atrial node - is situated. This signal crosses the atria, making them contract. Blood is pumped through the valves into the ventricles.

25. Where the atria meet the ventricles, there is an area of special cells - called the atrio-ventricular node - which pass the electrical signals throughout your heart muscle by a system of electrical pathways, known as the conducting system. The muscles of the ventricles then contract, and blood is pumped through the pulmonary and aortic valves into the main arteries. The heart’s natural ‘pacemaker’ - the sino-atrial node - produces another electrical signal, and the cycle starts again.

26. Blood pressure This is the measurement of the pressure within the arteries. It plays a vital role in the way your heart delivers fresh blood to all your blood vessels. For blood to travel throughout your body quickly enough, it has to be under pressure. This is created by the relationship between three things: your heart’s pumping action the size and stretchiness of your blood vessels the thickness of the blood itself

27. Heart Conduction System

28. Mechanical events of the  cardiac cycle Atrial Events (0.8 Sec); 1.Atrial systole (0.1 Sec) 2.Atrial diastole (0.7 Sec) Ventricular Events (0.8 Sec); 3.Ventricular systole . (0.27 Sec) Isovolumetric contraction (0.05Sec) Rapid ejection (0.13 Sec) Reduced ejection (0.09 Sec) 4.Ventricular diastole (0.53 Sec) Proto diastole (0.04 sec) Isovolumetric ventricular relaxation (0.08 sec) Earlier rapid filling (0.1 sec) Reduced filling (0.19 sec) Last rapid filling due to atrial systole (0.11 sec)

29. Atrial systole (Atrial Contraction) Lasts about 0.1 sec. It follows the impulse generation in SA node and atrial depolarization. When the atrial muscle contracts, pressure in atria increases. 30% of blood is propelled into ventricle. Narrowing of opening of SVC and IVC and pulmonary veins occur.

30. Ventricular systole Isovolumetric  contraction In isovolumetric  contraction ventricular pressure  exceed  atrial pressure closure of AV valves occur producing first heart sound. Opening of aortic valve occur when left ventricular pressure is > 8OmmHg. Opening of pulmonary valve is seen when right ventricular pressure > 10 mmHg. This will result in small rise in atrial pressure. Rapid ejection After opening of the aortic and pulmonary valves, ventricular ejection begins. Intraventricular pressure rises to a maximum of 120 mmHg in left ventricle and 25mmHg in right ventricle. 2/3rd stroke volume is ejected during this phase.

31. Reduced ejection phase Ventricular pressure decreases during this phase. Arterial pressure increases. Ventricular diastole 1. Protodiastole  At the end of ventricular systole, ventricular pressure falls, arterial pressure is more than  pressure inside the ventricle resulting in closure of semilunar valves which produce second heart sound. 2.Isovolumetric ventricular relaxation Ventricular pressure drop rapidly in this phase ,the ventricular muscle relax without change in ventricular volume. This phase ends when ventricular pressure drops below atrial pressure resulting in opening of AV valves.

32. 3.Phase of earlier rapid filling Rapid filling of ventricles occur. Pressure inside the ventricles remains low. 4.Phase of reduced filling Filling of ventricles is due to continous venous return filling  both atria and ventricle. 70% ventricular filling. 5.Last rapid filling Corresponds to atrial systole. 30% filling occur in this phase. Atrial diastole Atrial muscle relax and atrial pressure increase gradualy due to continous venous return. After the opening of atrioventricular valves pressure drops to zero and again slowly rises until the next atrial systole.

33. https://upload.wikimedia.org/wikipedia/commons/thumb/3/38/2027_Phases_of_the_Cardiac_Cycle.jpg/800px-2027_Phases_of_the_Cardiac_Cycle.jpg

34. Cardiac Output The amount of blood ejected by each ventricle in one minute is called cardiac output (CO). Cardiac output  = Heart rate × Stroke volume Pulse pressure (PP) is the difference between systolic blood pressure (SBP) and diastolic blood pressure (DBP). Cardiac Reserve: The difference between the maximum and resting cardiac output is called cardiac reserve.

35. CORONARY CIRCULATION Heart is supplied by TWO CORONARY arteries: 1- Left coronary artery---(LCA) 2- Right coronary artery---(RCA) These coronary arteries arise at the root of the aorta. 54

36. Diagram of coronary circulation 55

37. Coronary Arteries

38. 57 Special features of veins Valves Prevent backflow Most abundant in legs (where blood has to travel against gravity) Muscular contraction Aids the return of blood to heart in conjunction with valves

39. 58 Exercise helps circulation (because muscles contract and squeeze blood back to the heart)

40. 59 Vascular System ( Blood vessels of the body) Two circulations Systemic Pulmonary Arteries and veins usually run together Often nerves run with them

41. 60 Pulmonary Circulation Pulmonary trunk branches Right and left pulmonary arteries Division into lobar arteries 3 on right 2 on left Smaller and smaller arterioles, into capillaries surrounding alveoli Gas exchange

42. 61 Pulmonary Circulation After gas exchange blood enters venules Larger and larger into Superior and Inferior Pulmonary veins Four Pulmonary Veins empty into left atrium

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44. 63 Systemic Circulation Oxygenated blood to body Leaves LV through Ascending Aorta Only branches are the 2 coronary arteries to the heart Aortic Arch has three arteries branching from it: Brachiocephalic trunk, has 2 branches: Right common carotid a. Right subclavian a. Left common carotid a. Left subclavian a. Ligamentum arteriosum connecting to pulmonary a.

45. 64 Hepatic portal system Picks up digested nutrients from stomach & intestines and delivers them to liver for processing and storage Storage of nutrients Detoxification of toxins, drugs, etc. Tributaries of hepatic portal vein: - superior mesenteric vein -splenic vein -inferior mesenteric vein

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