Fisiologi Peredaran Darah. Tahun ajaran

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1 Fisiologi Peredaran Darah Tahun ajaran

2 Komponen Sistem Peredaran darah 1. Jantung 2. Pembuluh Darah 3. Sel-sel Darah

3 The circulatory system keeps blood pumping despite gravity s pull Muscle contractions help blood travel uphill in the veins of a giraffe s long legs The wriggling of the corn snake squeezes its veins and increases circulation

4 Fungsi SPD It transports O 2 and nutrients to cells It takes away CO 2 and other wastes

5 Kapiler merupakan bagian SPD yang berhubungan langsung g dengan jaringan tubuh Capillary Red blood cell

6 Keluar masuk substansi dari/ke jaringan yang jauh kapiler dibantu oleh cairan interstisial Capillary INTERSTITIAL FLUID Diffusion of molecules Tissue cell

7 Sistem Peredaran Darah Sistem Terbuka Tubular heart Pores Sistem tertutup Arteriole Capillary beds Artery (O 2 -rich blood) Gill capillaries Artery (O 2 -poor blood) Atrium Ventricle Venule Vein Heart

8 FISHES AMPHIBIANS REPTILES (EXCEPT BIRDS) MAMMALS AND BIRDS Gill capillaries Lung and skin capillaries Lung capillaries Lung capillaries At Artery Gill circulation Heart: ventricle (V) Atrium (A) Systemic circulation Vein Right Pulmocutaneous Pulmonary circuit systemic circuit aorta Pulmonary circuit A A A Left A Systemic A A V V V aorta V V Right Left Right Left Right Left Systemic Systemic circuit circuit Systemic capillaries Systemic capillaries Systemic capillaries Systemic capillaries Figure 42.4

9 Superior vena cava 7 Capillaries of Head and arms Pulmonary artery Pulmonary artery Capillaries of right lung 9 Aorta Capillaries of left lung Pulmonary vein RIGHT ATRIUM RIGHT VENTRICLE Inferior vena cava Pulmonary vein 1 5 LEFT ATRIUM LEFT VENTRICLE Aorta SPD Manusia 8 Capillaries of abdominal organs and legs

10 Struktur Jantung Pulmonary artery Aorta Superior vena cava RIGHT ATRIUM Pulmonary artery LEFT ATRIUM Pulmonary veins Pulmonary veins Semilunar valve Semilunar valve Atrioventricular valve Atrioventricular valve Inferior vena cava RIGHT VENTRICLE LEFT VENTRICLE

11 The cardiac cycle Semilunar valves closed 2 Atrial systole; ventricular diastole 0.4 sec 0.1 sec 0.3 sec Semilunar valves open AV valves open 1 Atrial and ventricular diastole AV valves closed 3 Ventricular systole; atrial diastole

12 The control of heart rhythm 1 Pacemaker generates wave of signals to contract. 2 Signals are delayed at AV node. 3 Signals pass to heart apex. 4 Signals spread Throughout ventricles. SA node (pacemaker) AV node Bundle branches Heart apex Purkinje fibers ECG Figure 42.8

13 Ritmisitas Kontraksi-Relaksasi Jantung Diastole Blood flows from the veins into the heart chambers 1 Heart is relaxed. AV valves are open. 2 Atria contract. Systole The atria briefly contract and fill the ventricles with blood Then the ventricles contract and propel blood out DIASTOLE 0.4 sec 0.1 sec 0.3 sec SYSTOLE 3 Ventricles contract. Semilunar valves are open.

14 Heart valves prevent backflow Cardiac output t The amount of blood pumped into the aorta by the left ventricle per minute Blood pressure depends on cardiac output resistance of vessels

15 The pacemaker sets the tempo of the heartbeat The SA node (pacemaker) generates electrical signals that trigger the contraction of the atria The AV node then relays these signals to the ventricles Pacemaker (SA node) AV node Specialized muscle fibers Right atrium Right ventricle ECG

16 Blood pressure 1 A typical blood pressure reading for a 20-year-old is 120/70. The units for these numbers are mm of mercury (Hg); a blood pressure of 120 is a force that can support a column of mercury 120 mm high. 4 The cuff is loosened further until the blood flows freely through the artery and the sounds below the cuff disappear. The pressure at this point is the diastolic pressure remaining in the artery when the heart is relaxed. Rubber cuff inflated with air Pressure in cuff above 120 Pressure in cuff below Blood pressure reading: 120/70 Pressure in cuff below Artery Artery closed Sounds audible in stethoscope Sounds stop Figure A sphygmomanometer, an inflatable cuff attached to a 3 A stethoscope is used to listen for sounds of blood flow pressure gauge, measures blood pressure in an artery. The cuff is wrapped around the upper arm and inflated until the pressure closes the artery, so that no blood below the cuff. If the artery is closed, there is no pulse below the cuff. The cuff is gradually deflated until blood begins to flow into the forearm, and sounds from blood flows past the cuff. When this occurs, the pressure pulsing into the artery below the cuff can be heard with exerted by the cuff exceeds the pressure in the artery. the stethoscope. This occurs when the blood pressure is greater than the pressure exerted by the cuff. The pressure at this point is the systolic pressure.

17 Measuring blood pressure can reveal cardiovascular problems Blood pressure is measured as systolic and diastolic pressures Blood pressure 120 systolic 80 diastolic (to be measured) Rubber cuff inflated with air Pressure in cuff above 120 Pressure in cuff below 120 Pressure in cuff below 80 Artery Artery closed Sounds audible in stethoscope Sounds stop

18 Epithelium Smooth muscle Connective tissue Epithelium CAPILLARY Basement membrane Epithelium Smooth muscle Connective tissue Valve ARTERY VEIN ARTERIOLE VENULE

19 Pressure is highest in the arteries Diastolic pressure Systolic pressure It drops to zero by the time the blood reaches the veins Relative sizes and numbers of blood vessels

20 Three factors keep blood moving back to the heart muscle contractions breathing one-way valves Direction of blood flow in vein Valve (closed) Skeletal muscle Valve (open)

21 Hypertension is persistent systolic pressure higher than 140 mm Hg and/or diastolic pressure higher than 90 mm Hg It is a serious cardiovascular problem e.g Heart Attack

22 What is a heart attack? A heart attack is damage that occurs when a coronary feeding the heart is blocked Aorta Right coronary artery Left coronary artery Blockage Dead muscle tissue

23 Blood vessel blockage is usually due to blood clots (see case of heart disease) Connective tissue Smooth muscle Epithelium Plaque

29 Smooth muscle controls the distribution of blood Muscular constriction of arterioles and precapillary sphincters controls the flow through capillaries Precapillary sphincters Thoroughfare channel Thoroughfare channel Arteriole Venule Arteriole Venule Capillaries 1 Sphincters relaxed 2 Sphincters contracted

30 The transfer of materials between the blood and interstitial fluid can occur by leakage through clefts in the capillary walls diffusion through the wall blood pressure osmotic pressure

31 Tissue cells Arterial end of capillary Osmotic pressure Osmotic pressure Venous end of capillary Blood pressure Blood pressure INTERSTITIAL FLUID NET PRESSURE OUT NET PRESSURE IN

32 Withdraw blood CONSTITUENT Place in tube PLASMA 55% MAJOR FUNCTIONS Centrifuge CELLULAR ELEMENTS 45% Water Salts Sodium Potassium Calcium Magnesium Chloride Bicarbonate Plasma proteins Albumin Fibrinogen Immunoglobins (antibodies) Solvent for carrying other substances Osmotic balance, ph buffering, and regulation of membrane permeability Osmotic balance, ph buffering Clotting Immunity Substances transported by blood Nutrients (e.g., glucose, fatty acids, vitamins) Waste products of metabolism Respiratory gases (O 2 and CO 2 ) Hormones CELL TYPE NUMBER (per mm 3 of blood) FUNCTIONS Erythrocytes (red blood cells) 5 6 million Transport of oxygen (and carbon dioxide) Leukocytes (white blood cells) Basophil Platelets Eosinophil Neutrophil Defense and 5,000 10,000, immunity 250, , Lymphocyte Monocyte Blood clotting

33 White blood cells function both inside and outside the circulatory system They fight infections and cancer Red blood cells contain hemoglobin Hemoglobin enables the transport of O 2 Basophil Eosinophil Monocyte Neutrophil Lymphocyte

34 When a blood vessel is damaged, platelets respond They help trigger the formation of an insoluble fibrin clot that plugs the leak

35 1 Injury to lining of blood 2 Platelet plug forms 3 vessel exposes connective tissue; platelets adhere Fibrin clot traps blood cells Connective tissue Platelet releases chemicals that make nearby platelets sticky Platelet plug Clotting factors from: Platelets Damaged cells Calcium and other factors in blood plasma Prothrombin Thrombin Fibrinogen Fibrin

36 All blood cells develop from stem cells in bone marrow Such cells may prove valuable for treating certain blood disorders

38 Peran Darah sebagai Immun system

12.1: The Function of Circulation page 478

12.1: The Function of Circulation page 478 Key Terms: Circulatory system, heart, blood vessel, blood, open circulatory system, closed circulatory system, pulmonary artery, pulmonary vein, aorta, atrioventricular