Do Now Finish the “Heart Disease” article and questions.

Cardiovascular System Ch.13

Objectives Identify the organs of the cardiovascular system and its overall function. Label the different parts of the heart.

The Cardiovascular System Pumps 7,000 liters of a blood a DAY!!! Contracts about 2.5 billion times in a lifetime Functions to carry oxygen and nutrients to the cells of the body and carry carbon dioxide and other waste away from the cells of the body.

Structures of the System Heart pumps blood to the lungs and throughout the body 2. Arteries, arterioles Carry blood AWAY from the heart to cells 3. Capillaries Tiniest tubes; place where nutrient and gas waste exchanges 4. Veins, venules Carry blood TO the heart from cells

Arteries vs. Veins Arteries Veins Strong, elastic, thick Carry blood AWAY from the heart under high pressure Veins Thinner, not as elastic Contain 1-way valves

Pulmonary vs. Systemic Circuits Carries Oxygen depleted blood (deoxygenated) to the lungs to pick up O2 and unload CO2. Systemic Sends oxygen-rich (oxygenated) blood from heart to all body cells.

The Heart Located in the thoracic cavity within mediastinum Rests on top of the diaphragm Distal end extends to the left Encased in a “parietal pericardium”

Wall of the Heart 1. Outer Epicardium (visceral pericardium) Serous membrane, consists of connective tissue Protects the heart by reducing friction 2. Middle Myocardium Thick, mostly cardiac tissue involved in pumping blood out of the heart 3. Inner Endocardium Made of epithelial and connective tissue Lines the inner chambers of the heart

Heart Chambers Atria Ventricles Septum Upper chambers Receive blood returning to the heart Ventricles Lower chambers Receive blood from atria and force blood into arteries Septum Separates left and right so blood doesn’t mix Septum *Remember anatomical position!!

Objectives Explain the flow of blood through the heart, lungs, and body. To label a diagram of the heart. Compare and contrast angina vs. a heart attack.

Heart Valves Atrioventricular Valves: separate atria from ventricles and prevent back-flow of blood: Tricuspid: Right side Bicuspid/Mitral: Left side Leaky valve

Heart Valves (cont.) Semilunar Valves: Pulmonary: Aortic: Found between the right ventricle and the pulmonary artery Aortic: Found between the left ventricle and the aortic arch

Heart Valve Abnormalities Heart “murmur” Regurgitation: valve doesn’t close properly, blood regurgitates back into atrium Mitral valve prolapse: valve contracts and stretches, bulging into the left atrium 2. Stenosis: not enough blood passes through Different heart sounds!

Heart Diagram Labeling!

Pathway of Blood Great Pathway of Blood Video!

Blood Flow Please fill out the pathway of blood through the heart on your worksheets!

Blood Supply to the Heart Coronary arteries: first two branches of the aorta supply blood to the tissues of the heart Cardiac veins: bring deoxygenated blood from heart tissue to coronary sinus (empties into right atrium)

Angina Pectoris A “thrombus” or “embolus” partially blocks or narrows a coronary artery and deprives myocardial cells of oxygen, causing pain. *many people mistake this for a heart attack A complete blockage by a blood clot is a myocardial infarction (aka heart attack)

Do Now What part of the heart pumps oxygenated blood to the body and what “tube” does it go through? Name 2 differences between arteries and veins. What is another name for the visceral pericardium?

Objectives To explain the flow of blood through both pulmonary and systemic circuits. To understand the cardiac cycle. To explain what causes your “heart beat”.

Do Now What do you think causes your heart beat? Write the flow of blood ONLY through the heart.

Objectives To explain what occurs in a normal cardiac cycle. To define systole and diastole. To measure ones pulse to determine their heart rate. To determine what causes heart sounds.

Cardiac Cycle Systole= contraction Diastole = relaxing * During atrial systole, ventricles are in ventricular diastole * During ventricular systole, atria are in atrial diastole Both relax briefly after ventricular systole Cycle Animation

Steps of the Cycle Pressure is low during ventricular diastole, opening the A-V valves (tricuspid/bicuspid) Ventricles fill with blood, atrial systole occurs A-V valves close when ventricular pressure exceeds atrial pressure Papillary muscles pull on chordae tendinae to prevent valves from bulging back into atria (which would cause a murmur) During ventricular systole, atrial pressure is low and they begin to fill up again

Steps of the Cycle 5) Ventricular pressure rises, opening the semilunar valves, forcing blood into the pulmonary trunk and aortic arch (ventricular systole) 6) Pressure drops in ventricles after contraction, and the semilunar valves close. Echocardiogram

Heart Sounds The heart makes a “Lubb-Dupp” sound The “Lubb” is the closing of the A-V valve during ventricular contraction. The “Dupp” is the closing of the semilunar valve when the ventricles are relaxing.

Pulse of Life Lab You will be measuring your pulse and seeing how your heart rate is affected by different activities! You will turn in the series of questions upon completing the lab as well as construct a graph.

Do Now Explain the steps of the cardiac cycle. How do you think these steps are coordinated?

Objectives To explain the cardiac conduction system To identify the components of an EKG To identify different heart arrhythmias

Cardiac Muscle Fibers Cardiac muscle fibers form a network called a functional synctium which contracts as a unit.

Cardiac Conduction System - Coordinates the events of the cardiac cycle

Cardiac Conduction System The Synoatrial Node (SA Node)- “Pacemaker” Specialized cardiac muscle tissue Can reach threshold on its own Generates impulses 70-80 times per minute Atrial synctium- causes atrial contraction A-V Node A-V Bundle (Bundle of His) Purkinje Fibers- causes ventricular contraction

Cardiac Conduction Conduction

Electrocardiogram Recording of the electrical changes that occur in the myocardium (cardiac muscle)

Electrocardiogram P-wave: depolarization of atria QRS: depolarization of ventricle fibers (R=Left, S=right) T-wave: repolarization of ventricles

Researching Arrhythmias V-fib (Ventricular Fibrillation) Sinus Bradycardia Sinus Tachycardia Atrial Fibrillation Atrial Flutter Asystole

Do Now In your own words, Explain the cardiac conduction system and how it works to control the cardiac cycle.

Objectives To identify EKG’s of different heart arrhythmias. To determine how fast a heart is beating by looking at an EKG. To explain blood pressure readings and understand how blood pressure can be effected.

Reading an EKG Read the article about reading an EKG! How can you figure out the rate?

Blood Pressure (13.5) Blood pressure= the force blood exerts against the inner walls of blood vessels. Interesting Fact! The human heart creates enough pressure to squirt blood 30 feet!!

Measuring Blood Pressure Systolic Pressure: max pressure during ventricular systole Diastolic Pressure: max pressure during ventricular diastole

What gives us a “pulse”? Ventricular contraction causes a “surge” in arteries, distending the elastic arterial walls, pressure drops immediately after contraction Only felt in arteries close to the surface such as your carotid in your neck.

Factors Affecting Blood Pressure Heart Action Stroke volume (vol of blood discharged with each contraction) and heart rate Blood Volume If you lose a lot of blood, your blood pressure will be lower. Peripheral Resistance If the vessels are constricted, pressure increased Blood Viscosity More viscous=more pressure