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 lub- dub 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