1. Circulatory System PART TWO

2. What’s your pulse? When you feel your pulse, you are feeling the alternate expansion and relaxation of an artery wall. The # of times the artery wall pulses is the # of times your heart beats. #6 HOW TO CALCULATE YOUR PULSE 1.Find your pulse on your wrist right below your thumb. 2.Count the # of pulses for 15 seconds. 3. Multiple by 4 to calculate the # of heart beats per minute.

4. Pacemakers Natural Pacemaker A bundle of neurons called sinoartrial (SA) node cause both atria to contract. Then the signal travels to the atrioventricular (AV) node and causes both ventricles to contract. The SA node is known as the natural pacemaker. Artificial Pacemaker When the natural pacemaker is defective, the heartbeat may be too fast, too slow or irregular. A small battery operated device with wires is implanted near the heart to maintain a normal heart beat by releasing electrical stimuli. #7

5. Natural Pace Maker SA

6. Artificial Pacemaker http://www.youtube.com/watch?v=SMXBR_YFocs

7. Atherosclerosis # 8 SymptomsCausesTreatments or Preventions Angina (chest pain) Arrhythmia (irregular heart beat) Shortness of breath Sleep problems Fatigue Plaque (fat and cholesterol) builds up inside the arteries overtime and hardens the artery walls. Limits the flow of O 2 rich blood to organs. Leads to heart attack, stroke or even death. Life Style Changes: - diet - exercise - stress management - quit smoking Medicine to lower cholesterol Angioplasty (surgery to widen the artery)

9. Heart Attack # 8 SymptomsCausesTreatments or Preventions Chest discomfort Discomfort in other parts of the body (arms, neck, jaw, stomach) Shortness of breath Cold sweat When one or more coronary artery become blocked, heart muscles die due to lack of oxygen SA Node unable to maintain a normal rhythm Electrical shocks from an external defibrillator (AED) Aspirin (to thin blood) Bypass surgery (healthy artery is cut somewhere else and attached to the heart) Life style changes http://www.youtube.com/watch?v=1qje-XlNowIhttp://www.youtube.com/watch?v=1qje-XlNowI http://www.youtube.com/watch?v=t7wmPWTnDbEhttp://www.youtube.com/watch?v=t7wmPWTnDbE

11. Stroke # 8 DescriptionSigns of Disease (Symptoms) Treatments or Preventions Blockage of arteries to the head Death of brain tissue due to lack of O 2 to the brain Face Drooping Arm Weakness Speech Difficulty Time to call 9-1-1 Blood thinning medications Rehabilitation Angioplasty Life style changes http://www.youtube.com/watch?v=PCNTMIcOMpE&NR=1&feature=fvwp