The Cardiovascular System Big Ideas: The heart is a pump Blood vessels are tubes circulating blood & the nutrients within it to all parts of the body

Anatomy of the Heart Muscle the size of your fist Cone-shaped Enclosed in mediastinum (medial thoracic cavity) Between the lungs Superior “base” / Inferior “apex” Thicker stronger left side Covered by pericardium

Anatomy of the Heart

Physiology of the Heart Two regulating systems of the heart Nerves of autonomic NS – breaks or accelerators depending on division Intrinsic conduction system – heart generates its own electricity to beat (auto-rhythmicity)

Physiology of the Heart ↓Click me for a video S-A node - pacemaker A-V node - signal delay Bundle branches & Purkinje fibers - rapid fire

Blood Flow Through the Heart Pulmonary circuit – right side, blood gets O2 (heart  lungs  heart) Systemic circuit – left side, pumps oxygenated blood throughout body (heart  body  heart)

Cardiac Cycle and Sounds Systole – means contraction Diastole – means relaxation Blood pressure = Systole / Diastole Normal Heart sounds - Lub Dub S1 – cuspid valve closure S2 – lunar valve closure Murmurs – abnormal heart sounds

Cardiac Output (CO) Function of heart rate (HR) and stroke volume (SV) HR = # of beats / minute SV = volume of blood pumped / beat So…. CO = HR x SV Example: CO = HR (75 beats/min) x SV (70 ml / beat) CO = 5250 ml/min

Arterial portion – blood away from heart Blood Vessels Arterial portion – blood away from heart Consists of arteries (biggest), arterioles (medium), and capillaries (smallest) Venous portion – blood toward heart Consists of veins (biggest), venules (medium), and capillaries (smallest)

Like a delivery driver using a road system….. Blood Vessels Like a delivery driver using a road system….. Package pick up (Cardio-respiratory etc.) Highways (arteries and veins) Secondary roads (arterioles and venules) Alleyways (capillaries) – site of nutrient and gas exchange

Capillary Exchange of Gases & Nutrients Nutrient and oxygen rich blood move from large arteries (highways through the body) to smaller arterioles (roads taking blood to different “towns” or organs), to tiny capillary beds where nutrients and oxygen are exchanged for carbon dioxide and metabolic wastes. This all works based off of a concentration gradient Things move from high to low concentrations If tissues use oxygen to live then they are using O2 and the concentration is lower than it is in oxygen rich arterial blood so that’s where it flows.

Blood Vessels Veins tend to be more elastic (more stretchy) and contain one way valves (like the heart) in order to act as a holding tank for blood and to prevent the backward flow of blood through the system.

Major Blood Vessels

Pulse / Pressure Points Pulse – pressure wave created by ventricles felt everywhere in the arterial system Pulse points – places where you can feel this pressure Pressure points – places where you can apply pressure to stop blood loss if your leaking

Pulse / Pressure Points ↑Click me for a video!

BP - force exerted on large systemic arteries near heart Blood Pressure (BP) BP - force exerted on large systemic arteries near heart BP = Systole / Diastole Systole – top number, max force during ventricular contraction Diastole – bottom number, minimal force during ventricular contraction

Factors Regulating BP Age, weight, time of day, exercise, body position, emotional state and various drugs to name a few, but more importantly……. Neural factors (vasoconstriction/dilation) Renal factors Temperature Chemicals (epinephrine) Diet (sodium)

H.I. of the Cardiovascular System Pericarditis (look me up on page 363) Endocarditis (look me up on page 366) Angina pectoris & myocardial infarctions (look me up on page 368) Ischemia & fibrillation (look me up on page 369) Murmurs (look me up on pages 371 & 372) Congestive heart failure (look me up on page 374) Varicose veins (look me up on page 377) Orthostatic hypotension & hypertension (look me up on page 391) Coronary artery disease (look me up on page 397)