NPB Study Guide Midterm 2

Putting it all together typically two muscles control

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Unformatted text preview: - it’s primary role is to move molecule throughout the body - it consists of: pump, blood vessels “pipes”, and a liquid medium- blood (CT) 2. Organization of the Cardiovascular System A. Systemic Circulation - delivers O , glucose, hormones (“fuels”), other matters ti TISSUES - removes CO , wastes, sometimes excess heat from tissues ~ remove temperature by changing blood flow - all tissues of the body B. Pulmonary Circulation - delivers O - deficient, CO - rich blood to the lungs - allows gas exchange between the respiratory system and blood - exchange of gases from lungs and blood → goes to lungs II. The Heart 1. The Heart is a Pump that Creates Pressure *Automatic* A. The heart squeezes blood within its muscular walls - creates pressure - pressure differences all blood to move from point A to point B - pressure= force / surface area - high pressure → low pressure B. The hearts consists of - cardiac muscles → excitable - conductive tissue → excitable - connective tissue C. Chambers - Atria - Ventricles - Septum (walls between left and right) * Left ventricle has thicker cardiac muscle * 2. Blood Flows Only One Direction in the Heart A. The direction of flow - blood flows in via the vena cava → right atrium → right ventricle → pulmonary trunk - blood flows in via pulmonary veins → left atrium → left ventricle → aorta B. Valves prevent backwards flow - Atrioventricular valves → passive - Semilunar valves → active 3. Pacemaker Cells and Conductive Pathways - the contractions of the atria and ventricles occur automatically ~ atria beat first, followed by the ventricles - “primary pacemaker” A. The Sinoatrial Node - generates an electrical signal called the pacemaker potential (it’s an AP) - the pacemaker potential spreads throughout the heart via conductive pathways B. The Atrioventricular Node - temporarily delays the pacemaker potential before it spreads to the ventricles 4. How Do We Monitor the Heart’s Activity A. Electrocardiogram (ECG) - a physician attaches several electrodes to the chest of a patient to record this - arises from electrical activity in the heart. Can monitor from skin’s surface * Portions respond to certain events in the heart and where it’s located on the body * - normal...
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