Lecture 8. Heart and Circulatory System. Lecture 8

Transcription

1 Lecture 8 Heart and Circulatory System Lecture 8 1. Introduction 2. Blood 3. Blood Vessels & Blood Pressure 4. The Heart 5. Cardiovascular (Circulatory) System 2 1

2 Circulatory System Function 1. Transport System (gases, nutrients, hormones) 3 Circulatory System Function 2. Heat Distribution System 4 2

3 Circulatory System Function 3. Heals wounds and fight off diseases 5 Homeostasis Maintenance of a relatively constant internal state under a much wider range of environmental conditions. 3

4 Blood Blood The red fluid that circulates in our blood vessels Primary Function -Transports Oxygen and CO 2 Main player in the body s defense against infection 8 4

5 Hemopoietic Tissues Hemopoiesis blood formation Bone Marrow, Spleen, Liver, and Kidneys 9 Blood Two main components to blood: 1. Blood Plasma 2. Blood Cells (Cellular Component) 10 5

6 Blood Plasma Fluid component of the blood Makes up 55% to 60% of total blood volume About 92% is water (almost identical to sea water) Other 8% is blood proteins and trace materials 11 Blood Cells Red Blood Cells (Erythrocytes) 95% of cellular component 12 6

7 Red Blood Cells (Erythrocytes) Hemoglobin Molecules About 250 million /cell 13 Red Blood Cells (Erythrocytes) 14 7

8 White Blood Cells (Leucocytes) 4% of cellular component 15 White Blood Cells (Leucocytes) 4% of cellular component 16 8

9 Platelets (Thrombocytes) Less than 1% of cellular component Not Cells! Blood Types Although all blood is made of the same plasma and cells, not all blood is alike. Eight different common blood types Blood Type Antigens on the surface of the red blood cells. A antigens, B antigens Antigens can trigger a patient's immune system to attack transfused blood, safe blood transfusions depend on careful blood typing and cross-matching. 9

10 Blood Types Blood Type A A antigens Blood Type B B antigens Blood Type AB both A and B antigens Blood Type O NO antigens 20 10

11 ABO Blood Group System Type O is the universal donor Cannot receive A, B or AB blood Type A can only receive Type A and Type O Type B can only receive Type B and Type O Type AB is the universal recipient Rh Factor In addition to the A and B antigens, there is a third antigen called the Rh factor, Rh can be either present (+) or absent ( ) In general, Rh negative blood is given to Rhnegative patients, and Rh positive blood or Rh negative blood may be given to Rh positive patients. 11

12 Rh Factor 23 Blood Types The approximate distribution of blood types in the U.S. population (distribution is different for specific racial and ethnic groups): O+ 39% O- 9% A+ 31% A- 6% B+ 9% B- 2% AB+ 3% AB- 1% 24 12

13 Circulatory System Structure Veins and Arteries Vein a blood vessel that carries blood toward (i.e. Back to) the heart Artery a blood vessel that carries blood away from the heart to the capillary networks Capillary site of exchange 13

14 Blood Vessel Types Arterial Portion Venous Portion Heart Artery Arteriole Capillary Capillary Venule Vein Heart About 70 % of the blood volume is found within the Venous portion Blood Vessels Arterioles Venules Aorta Vena Cava Capillaries 14

15 Venous Valves What is Blood Pressure? Systolic Pressure Diastolic Pressure 15

16 Blood Pressure (mm Hg) Blood Pressure Variation Systolic Diastolic Arteries Arteriole Capillary Venules Veins Measuring Blood Pressure Sphygmomanometer 16

17 Blood Pressure The Heart 34 17

18 The Heart Muscular Pump Receives blood low pressure then increases the pressure Heart consists of 4 chambers: Atria (2) receive venous blood from the lungs and body circulation. Ventricles (2) receive blood from the Atria and pumps blood out of the heart to lungs and body The Heart 18

19 Heart RA - Right Atria LA - Left Atria RV - Right Ventricle LV - Left Ventricle RA RV LA LV 37 Heart RA - Right Atria LA - Left Atria RV - Right Ventricle LV - Left Ventricle RA RV LA LV 38 19

20 Heart From Body RA LA From Lungs To Lungs RV LV To Body Cardiovascular System 40 20

21 The Cardiovascular System Cardiovascular System - the heart and blood vessels that circulate blood throughout the body Pulmonary Circulation - the pumping of oxygen-poor blood to the lungs and oxygen-rich blood back to the heart by the right side of the heart Systemic Circulation - the pumping of oxygen-rich blood to the body and oxygen-poor blood back to the heart by the left side of the heart 42 21