The Cardiovascular System 1

Ch. 11 Vocabulary angina pectoris endocardium pulse aorta epicardium superior vena cavae arteries infarct systole atria inferior vena cavae tachycardia blood pressure mediastinum valves capillary myocardial infarction veins congestive heart failure myocardium ventricles coronary arteries pericardium vital signs diastole pulmonary circulation 2

COLOR CODE FOR PLATES 49 & 50 purpleorange Trachea – purpleRight atrium – orange browndark brown Esophagus – brownTricuspid valve – dark brown – peachbrown Lungs – peachRight ventricle – brown orange – gray Diaphragm – orangeSeptum – gray light blue- purple **Pericardium – light bluePulmonary valve - purple dark greenyellow *Superior vena cava – dark greenLeft atrium – yellow green *Inferior vena cava – greenBicuspid valve – black redtan *Aorta – redLeft ventricle – tan pinkpeach *Pulmonary arteries – pinkAortic semilunar valve - peach aqua *Pulmonary veins – aqua blue *Myocardium – blue dark blue *Endocardium – dark blue * found on both sides **this is for ALL pericardium (there are multiples listed on plate 49) & on plate 50 the epicardium is also a type of pericardium 3

COLOR CODE FOR PAGE 63 & PLATE 48 Page 63 blue Deoxygenated blood – blue purple Capillary blood – purple red Oxygenated blood – red yellow Systemic circulation – yellow pink Pulmonary circulation – pink Plate 48 For letters a-h follow directions listed in #1. green I – green dark blue J – dark blue dark pink/magenta K – dark pink/magenta 4

I. CARDIOVASCULAR SYSTEM A. Functions: 1. provide O 2 & nutrients to tissues 2. removes wastes B. Consists of: 1. heart 2. arteries & arterioles 3. capillaries 4. veins & venules 5

II. THE HEART A. size: approx. 14 cm (5.5”) by 9 cm (3.5”) B. location: thoracic cavity, b/t lungs, rests on diaphragm C. covering: pericardium a. layered, tough, protective sac b. encloses heart and ends of blood vessels wh/ attach to it c. small amt. of fluid is b/t the inner layers in order to reduce friction as heart beats 6

D. walls (3 layers) 1. epicardium a. outer wall of the heart b. protects heart by reducing friction 2. myocardium a. thick, middle layer of heart wall that contains contractile cardiac muscle b. forces blood out of heart chambers 3. endocardium a. inner layer b. contains blood vessels and cardiac muscle fibers 7

E. chambers & valves 1. chambers 4 total – 2 upper, 2 lower a. atria 1)upper chambers (superior) 2)receive blood returning to the heart (receiving chambers) 3)right atrium – receives blood from body through inferior & superior vena cavas 4)left atrium – receives blood from lungs through pulmonary veins b. ventricles 1)lower chambers 2)receives blood from atria 3)right ventricle – pumps blood to lungs 4)left ventricle – pumps blood to all body parts; has thickest walls 8

c. septum 1)separates atrium and ventricle of right side from those on left side 2)÷ heart longitudinally 2. valves a. ensures one way blood flow b/t atria & ventricles b. prevents backflow c. tricuspid valve *lies b/t right atria and ventricle d. bicuspid (mitral) valve *lies b/t left atria and ventricle tricuspid & bicuspid prevents backflow i/t atria during contractions 9

e. pulmonary valve *lies b/t right ventricle and pulmonary arteries f. aortic valve *lies b/t left ventricle and aorta pulmonary & aortic valves prevent backflow i/t ventricles during relaxation 10

Pulmonary Valve Right Atrium Tricuspid Valve Right Ventricle Aortic Valve Left Atrium Bicuspic/Mitral Valve Left Ventricle 11

F. Blood Flow 1. blood enters the heart twice - *once from the body *once from the lungs 2. blood route: blood from body → inferior/superior vena cavas → right atrium → through tricuspid valve → right ventricle → pulmonary valve → pulmonary arteries → lungs (get oxygenated) → pulmonary vein → left atrium → through bicuspid valve → left ventricle → aortic valve → aorta → body 12

Superior Vena Cava Inferior Vena Cava Right Atrium Tricuspid Valve Right Ventricle Pulmonary Valve Pulmonary Arteries to lungs Pulmonary Veins Left Atrium Bicuspid /Mitral Valve Left Ventricle Aortic Valve Aorta 13

14

III. HEART ACTION A. Cardiac Cycle 1. atria contract as ventricles relax; atria relax as ventricles contract 2. pressure in the chambers rises and falls in repeated cycles B. Heart Sounds due to vibrations that the valve movements produce C. electrocardiogram (ECG) – pg records electrical changes in the myocardium during a cardiac cycle 2. pattern shows various waves that correspond to atria and ventricle conditions D. cardiac cycle regulation 1. physical exercise, body T, & conc. of various ions affect heartbeat 2. cardiac center in medulla oblongata regulates autonomic impulses to the heart 15

IV. BLOOD VESSELS A. forms a closed circulatory system B. circuit of tubes that carries blood from the heart to cells and back again C. arteries and arterioles 1. arteries carry blood away from heart 2. arterioles smaller branches of arteries that connect to capillaries 3. both contain smooth muscle that can be stimulated for vasoconstriction (smaller diameter) or vasodilation (larger diameter) 16

D. capillaries 1. connect arterioles and venules 2. walls are very thin (single layer of cells) & form a semi-permeable membrane wh/ allows for diffusion 3. where exchange of gases, nutrients & metabolic by-products (waste products) occurs E. venules and veins 1. venules continue from capillaries & merge to form veins 2. veins carry blood to the heart 3. walls are thinner than arterial walls & contain < smooth muscle 4. outer coat composed primarily of collagen arteries → arterioles → capillaries → venules → veins 17

18

V. Paths of Circulation A. pulmonary circuit consists of vessels that carry blood from the right ventricle to the lungs and back to the left atrium B. systemic circuit 1. consists of vessels that lead from the heart to the body cells and back to the heart 2. includes the aorta and its branches 19

20

VI. Vital Signs A. msmts of: 1. arterial pulse 2. blood pressure 3. respiratory rate 4. body T B. Arterial Pulse 1. due to alternating expansion & recoil of an artery 2. creates a pressure wave 3. normal resting is approx bpm (pulse rate normally = heart rate) 4. heart rate: a. tachycardia – rapid; > 100 bpm b. bradycardia – slow; < 60 bpm 21

C. Blood Pressure 1. P blood exerts a/g inner walls of blood vessels 2. systolic P a) P in peak of ventricular contraction b) written first (top #) 3. diastolic P a) P when ventricles are relaxing b) written 2 nd (bottom #) 4. borderline # is 120/80 22

VII. HEART CONDITIONS A. Congenital heart defects 1. approx. ½ of all infant deaths assoc. w/ congenital defects 2. can include, but not limited to: a. arterial ducts that do not close b. septal openings c. structural abnormalities 3. mj. cause – maternal infection / drug ingestion during 1 st 3 months when fetal heart is forming 23

B. Hypertension ( ↑ BP) 1. warns of ↑ resistance 2. heart works a/g resistance → works harder → myocardium enlarges → heart weakens & walls b/c flabby 3. factors involved: a. diet b. obesity c. heredity d. race e. stress 4. > in females than males; > in blacks than whites; runs in families; common in obese people due to increased length of blood vessels (for ea. lb. of fat miles of +tional bl. vessels are required) 24

C. CHF (Congestive Heart Failure) 1. heart’s pumping efficiency is ↓ 2. circulation inadequate to meet tissue needs 3. progressive condition → heart failure D. Angina pectoris 1. crushing chest pain 2. due to myocardium being deprived of O 2 E. Myocardial Infarction 1. commonly called a heart attack/coronary 2. heart cells die → infarct 25

####### ########### ############# 26