Unit 10 Cardiovascular System

Transcription

1 Unit 10 Cardiovascular System I. Functions Deliver nutrients to cells > O 2, sugars, amino acids, lipids, ions, H 2 O... Remove waste from cells > CO 2, pathogens, toxins, lactic acid... Fight off infection > houses immune cells Maintain homeostasis > temperature, H 2 O, ph, O

2 II. Blood Consists of: 90% > Plasma: Liquid portion (water, amino acids, carbohydrates, lipids, vitamins, hormones, electrolytes, respiratory gases, & waste products) > Formed Elements: WBCs, RBCs, Platelets Hematocrit: > % formed elements (~RBCs) II. Blood cont'd Hemopoiesis: > Blood cell production > Blood cells originate from cell known as hemocytoblast (in bone marrow) then develop into red/white blood cells some WBCs can develop in lymphatic tissue 2

3 III. Types of Formed Elements Red Blood Cells: (Erythrocytes) > Contains protein hemoglobin transports O 2 & CO 2 > Erythropoietin / EPO (hormone) controls RBC production throughout lifetime Kidneys mainly release > Homeostatic Imbalance: Sickle Cell Anemia «Causes mis shaped hemoglobin, bending RBCs into sickle shape What physiological changes would you observe in a person with Sickle Cell disease? III. Types of Formed Elements cont'd White Blood Cells: (Leukocytes) > protects against disease > Types of WBCs & General Functions: Neutrophils phagocytize bacteria Eosinophils kill anything marked by antibodies «kill parasites & control inflammation Monocytes large macrophages outside of blood Basophils prevents blood clotting (heparin) «releases histamine (increase blood flow to tissues) Lymphocytes important in immunity «produces antibodies that attack foreign substances «B cells, T cells, NK cells > Homeostatic Imbalances: Leukopenia Leukocytosis Leukemia 3

4 III. Types of Formed Elements cont'd Platelets: (Thrombocytes) > Cell fragments involved in initial formation of blood clots > Homeostatic Imbalance: Thrombus vs Embolus Hemophilia IV. Blood Plasma Transports nutrients, gases, vitamins Regulates fluid & electrolyte balance Plasma Proteins (main types): produced by liver > Albumins regulate water movement > Globulins antibodies & transport proteins transport lipids & hormones > Fibrinogens role in coagulation (clotting) Gases & Nutrients: > Gases O 2 & CO 2 > Nutrients amino acids, simple sugars, nucleotides Plasma Electrolytes: > Na +, K +, Ca 2+, Mg 2+, Cl, bicarbonate, phosphate, sulfate ions 4

5 V. Blood Types Determined by specific antigens on RBC Universal Donor: Universal Recipient: Rh Factor: +/ depending on presence of Rh antigen > problems if mom ( ) and baby (+) VI. Cardiovascular System Composed of Heart & Blood Vessels Circuits: > Pulmonary Circuit: > Systemic Circuit: 5

6 VII. Heart Anatomy 4 Chambers: > Right & Left Atria: Receive blood returning to heart > Right & Left Ventricles: Contract to force blood out of heart to arteries VII. Heart Anatomy cont'd Heart Valves: prevent backflow > AtrioVentricular (AV) valves: Tricuspid (right side) Bicuspid or Mitral (left side) > Semilunar Valves: Pulmonary (leaving right side) Aortic (leaving left side) When ventricles contract: > AV valves close > SL valves open 6

7 VII. Heart Anatomy cont'd Heart Terms: > Endocardium: inner lining of heart Makes valves > Myocardium: cardiac muscle tissue Contracts > Epicardium: outer layer Visceral serous membrane Pericardium > Chordae Tendineae: fibrous strings attach AV valves to mounds of cardiac muscle (called papillary muscle) 7

8 VIII. Blood Vessel Anatomy Arteries: > Carry blood away from heart > Thicker and more elastic than veins Arterioles: > Smaller vessels than arteries > Still carrying blood away from heart Capillaries: > Smallest blood vessels (single cell layer thick) > Connects arterioles to venules > Place of exchange for materials coming into and out of blood stream Venules: > Microscopic vessels connecting capillary beds to veins Veins: > Carry blood back to heart > Thinner walls and less elastic > Have valves to prevent back flow due to low pressure > What are other mechanisms that help venous return? 8

9 IX. Blood Flow Pathway Systemic Circuit (out of heart) AORTA SYSTEMIC ARTERIES ARTERIOLES (away from heart) HEART CAPILLARIES (exchange in body) VENA CAVAE SYSTEMIC VEINS VENULES (towards heart) Arteries do NOT always carry oxygenated blood!! Veins do NOT always carry deoxygenated blood!! Blood Flow Pathway Pulmonary Circuit (out of heart) PULMONARY TRUNK PULMONARY ARTERIES (away from heart) ARTERIOLES HEART CAPILLARIES (exchange in lungs) PULMONARY VEINS VENULES (towards heart) Blood Flow Pathway Coronary Circulation Arteries & Veins that supply and drain blood to and from heart muscle itself Nourishes myocardium BLOOD PATHWAY: 9

10 10