Transcript File
Circulatory System circulatory system circulatory sustem2 Functions • To take oxygen and nutrients to all parts of the body • To take carbon dioxide and waste products out of the body • oxygen transport 2 Pathways • Systemic- delivers blood to all body cells and carries away wastes • Pulmonary- eliminates carbon dioxide and oxygenates blood Heart • the beast within • Pericardium- the membrane that encloses the heart • Pericardial cavity: contains fluid for the heart to float in, reducing friction • open heart surgery Layers of the heart muscle • Epicardium- outer layer, Protects the heart by reducing friction • Myocardium- cardiac muscle- Pumps blood out of the heart • Endocardium- inner layer- Contains blood vessels and purkinje fibers Chambers and Valves • Atria- top chambers • Ventricles- bottom chambers • Septum: divides the left and right sides • blood flow through the heart • blood flow • heart dissection Chambers and Valves • Atrioventricular Valve (AV): located between the atrium and ventricle • Tricuspid: right side of AV • Bicuspid: left side of AV (mitral) • Pulmonary valve: controls blood flow to the lungs • Aortic valve: controls blood flow into the aorta Veins and Arteries • Arteries: carry blood away from the heart • Capillaries: small arteries • Veins: return blood to the heart • Venules: small veins • Superior vena cava: from upper body to heart • Inferior vena cava: from lower body to heart • Pulmonary veins: returns oxygenated blood to the heart • Pulmonary arteries: takes deoxygenated blood to the lungs to pick up oxygen • Aorta: largest vessel that takes blood to the body Blood vessels • Vasoconstriction- (contracted) reduced diameter of blood vessels • Vasodilation- (relaxed) increased diameter of blood vessels Blood supply to the heart • Coronary Arteries- supply blood to the heart • Cardiac Veins- drain blood from the heart Heart Actions • Cardiac cycle: one complete heartbeat • Systole: contraction of a heart chamber • Diastole: relaxation of a heart chamber • Sphygmomanometer: device used to measure blood pressure • Blood pressure: the force of blood against the walls of the arteries Blood Pressure • Systolic: when blood is being forced out of the left ventricle (top number) • Diastolic: when the ventricle relaxes (bottom number) • Normal BP: 120/80 • Normal HR: 72 bpm • Hypertension: high blood pressure Heart beat • Heart Sounds: opening of valves causes the lubdub sound • Stethoscope: device used to listen to heart sounds • Sinoatrial Node (S-A node): the pacemaker of the heart that controls its rhythmic pulse • Atrioventricular node (A-V node): conducts impulses from the atria through the septum • Purkinje fibers: nerve fibers in the ventricles that carry nerve impulses for contractions • Electrocardiogram (ECG)- a record of the electrical changes in the heart Heart beat • Tachycardia- irregularly fast heart beat 100+ beats per minute • Bradycardia- reduced heart rate fewer than 60 BPM • Fibrillation: rapid, uncontrolled heartbeats • Ventricle fibrillation: deadly • Atrial fibrillation: not serious • defibrillator Disorders 1. Mitral Valve Prolapse: mitral valve does not close all the way creating a clicking sound at the end of the cardiac cycle 2. Heart Murmurs: valves do not close completely causing a murmuring sound 3. Myocardial infarction: “heart attack” blood clot obstructs a coronary artery 4. Atherosclerosis: “clogged arteries” fatty deposits (plaque and cholesterol) in the arteries reducing blood flow Disorders 5. Hypertension: high blood pressure: force within arteries is too high 6. Stenosis: narrowing of arteries slowing blood flow 7. Ventricular septal defect: holes in the ventricles allowing blood to leak into the other side