1. Opening Assignment – Copy and answer 1. The two chambers on the superior side of the heart are called ________________. 2. The two chambers on the inferior side of the heart are called the ________________________. 3. Veins carry ______________________________blood to the heart and arteries carry _________________________________ blood away from the heart. 4. The exception to this rule is the _________________________________ artery that carries deoxygenated blood to the lungs and the _____________________________veins that carry oxygenated blood to the heart.

2. How the Heart Beats! BY MR. & MRS. SHAW

3. Review of blood flow through the heart 1.Blood flows into the right atrium from the inferior and superior vena cava. 2.With an atrial contraction, blood flows into the right ventricle. 3.With a ventricular contraction, blood flows into the pulmonary artery into the lungs for gas exchange to occur. 4.Oxygenated blood then flows into the left atrium via the pulmonary veins on both sides of the heart. 5.On contraction it then goes into the left ventricle and finally out through the Aorta to be taken to body tissues for gas exchange again.

4. Electrical Conduction in the Heart  Regulation of the heart beating is part of the autonomic nervous system.  The heart actually has it’s own intrinsic cardiac conduction system.  Depolarization is the shift in ions (Calcium ions flow in) to start the contraction.  Repolarization happens when ions (Potassium) move out of cells and relaxation occurs.

5. The Path of Conduction https://www.youtube.com/watch?v=v3b-YhZmQu8 Electrical signals arising in the SA Node (located in the right atrium) stimulate the atria to contract, and travel to the Atrioventricular node (AV node), which is located in the interatrial septum. After a delay, the stimulus diverges and is conducted through the left and right Bundle of HIS to the respective Purkinje fibers for each side of the heart, as well as to the endocardium at the apex of the heart, then finally to the ventricular epicardium Pacemaker of heart

6. What does each part of an ECG mean?  P – wave – atrial depolarization (contraction)  Q-R-S complex – ventricular depolarization (contraction)  S-T segment – Ventricular repolarization (relaxation)  The atrium is repolarizing while the ventricles are contracting so it hides behind the QRS complex.

7. Abnormal ECG’s Tachycardia: fast beat – contraction ( > 100 bpm) Bradycardia: slow beat – contraction ( < 60 bpm) Fibrillation: when a chamber doesn’t full contract

8. Abnormal ECG’s Myocardial Infarction shown on an ECG as an ST elevation. Atrial Fibrillation Ventricular fibrillation

9. Check for Understanding 1. The pacemaker of the hearts electrical system is the _______________________. 2. Depolarization means _____________________________ and repolarization means _____________________________. 3. _______________________________ is a heart rate less than 60 bpm and _______________________________ is a heart rate greater than 100 bpm. 4. When the atria or ventricles fail to completely contract it is called ________________________________.

10. Video – Cardiac Cycle  https://www.youtube.com/watch?v=NJzJKvkWWDc https://www.youtube.com/watch?v=NJzJKvkWWDc  Cardiac Cycle at 8:15 in.

11. Homework  Complete the survey to evaluate the Cardiovascular System group members.  Respiratory System Members you are presenting on Monday! Are you ready? I need the presentation totally completed by 4pm TODAY!!! I have to make a guided notes worksheet to use while you teach the material.  Field trip info!