CARDIOVASCULAR Brings O 2 and nutrients to all body cells and remove wastes.

1. CARDIOVASCULARBrings O2 and nutrients to all body cells and remove wastes. CHAPTER 13

3. HEART • Located in the pericardial/thoracic cavity(contains serous fluid to reduce friction) • Lined by a serous membrane called the pericardium • 3 layers • Epicardium-outer layer that protects heart • Myocardium-thick middle layer of cardiac muscle that forces blood out the heart chambers • Endocardium-inner layer that contains blood vessels that attach to the heart

5. 4 chambers • Atria: upper 2 chambers that have thin walls and receive blood returning to heart • Ventricles: lower 2 chambers that have thick walls and receive blood from atria then contract to force blood out of heart

6. Interventricular Septum-solid wall that separates the heart into left and right halves • Coronary arteries-supply blood to the hearts tissues (the 1st 2 branches of the aorta) • Cardiac veins& Coronary sinus: blood returns to the right atrium through these • Atrioventricular valves: tricuspid/bicuspid • Semilunar valves: pulmonary/aortic

7. PATH OF BLOOD FLOW THROUGH HEART • Superior & Inferior vena cava • Right atrium • Tricuspid valve • Right ventricle • Pulmonary valve • Pulmonary trunk • Pulmonary arteries • Lungs • Pulmonary veins • Left atrium • Bicuspid valve • Left ventricle • Aortic valve • Aorta • Your body

8. BLOOD VESSELS Artery arteriole capillary venule vein (away from heart)*site of nutrient, (back to heart) gas, and waste exchange • Closed system of blood circulation • Pulmonary circuit: sends deoxygenated blood to lungs • Systemic circuit: sends oxygenated blood and nutrients to all body cells and removes wastes • The heart pumps 7,000 liters of blood through the body each day, contracting some 2.5 billion times in an average lifetime.

10. CARDIAC CYCLE • The events of one complete heart beat (1 contraction & relaxation) that lasts about .8 sec. • Both atria contract while ventricles are relaxing. • Both atria relax while ventriclesare contracting. • Pressure within the chambers rises and falls causes the valves to open and close. • When ventricular pressure exceeds atrial pressure, the AV valves open. • Papillary musclescontract and pull chordate tendineaeto open and close the valves. They aid in preventing back flow of blood.

11. Heart beat sound: lupp-dupp • Lupp occurs when the AV valves are closing • Dupp occurs when the semilunar valves are closing • Cardiac conduction system coordinates the events of the cardiac cycle. • S-A node (sinoatrial node) or pacemaker • upper right atrium • generate the hearts rhythmic contractions • A-V bundle • Purkinje fibers

12. Electrocardiogram (ECG): recording of the electrical changes that occur in the myocardium during the cardiac cycle.

13. ECG cont… • S-A node triggers a cardiac impulse, atrialfibers depolarize(contraction), producing an electrical charge. • Ventricle walls are thicker causing a greater electrical charge. • Adult heart rate 60-100 beats per minute. Well trained athlete 40-60bpm. • Heart rate influences • Emotional upset, anxiety • Temperature change • Ion changes (K+, Ca+2)

14. BLOOD PRESSURE • Force blood exerts against the blood vessel walls. Specifically, pressure in arteries supplied by branches of the aorta. • Forces blood throughout the body. • Blood vessels walls are constructed to adequately carry blood (pg. 358) • Artery arteriole capillary venule vein Highest pressure Lowest pressure • Cut an artery, blood squirts out; cut a vein, blood flows out • Contraction of the human heart creates enough pressure to squirt blood 30 ft.

15. Blood Pressure cont.. • Systolic pressure: maximum pressure in the arteries during ventricular contraction. • Diastolic pressure: lowest pressure remaining in the arteries before the next ventricular contraction. • Average blood pressure 120/80 systolic/diastolic Arterial Pulse Temporal femoral Facial popliteal Carotid posterior tibial Brachial dorsalis pedis radial

16. Factors that influence blood pressure • Stroke volume: amount of blood discharged from ventricle with each contraction • Blood volume: sum of all blood components • Peripheral resistance: friction b/w the blood and blood vessel walls • Viscosity: consistency of blood

17. CARDIOVASCULAR DISORDERS • Tachycardia- abnormally fast heart beat – above 100 BPM • Bradycardia – slow heart beat – below 60 BPM • Murmur – abnormal heart sound due to incomplete closure of heart valves • Idiopathic cardiomyopathy– enlarged heart • Congenital defects– defect present at birth • Stenosis – narrowing of an opening • Myocardial infarction– heart attack • Angina pectoris– pain in the chest • Hypertension – high blood pressure (140/90)

18. Arrhythmias – abnormal heart rhythms • Atherosclerosis– a build-up of plaque in the arteries • Arteriosclerosis – hardening of the arteries • Coronary bypass– surgery using a vein from the leg or artery from the chest to correct blocked coronary arteries • Thrombus– blood clot • Embolus– moving blood clot • Ischemia– lack of blood flow and oxygen to heart • Aneurysm – a permanent weakness in an artery • Angioplasty – a catheter is inserted into an artery in the leg or arm and fed into a coronary artery • Cardiac output – the amount of blood the heart pumps each minute