West Coast EMT Block 2 Study Guide Graded A

electrical conduction of the heart The flow of electrical current causes smooth, coordinated heart contractions; they produce pumping action of the heart Depolarization electrical charges on the surface of the muscle cell change from positive to negative Repolarization the heart returns to its resting state, and the positive charge is restored to the surface Where do the electrical impulses begin? Electrical impulses begin high in the atria in the sinoatrial node, travel to the atrioventricular node and bundle of His, and then move through the Purkinje fibers to the ventricles Three types of muscle skeletal, cardiac, smooth Skeletal muscle Voluntary muscle/Striated muscle (characteristic stripes): Movement of the body like waving or walking/ Skeletal muscle is attached to the bones of the skeleton Smooth muscle Found within blood vessels and intestines Cardiac muscle found only within the heart and is able to create and conduct its own electrical impulses Ligaments Connect bone to bone Tendons Ropelike structures that connect muscles to bones Cartilage Smooth connective tissue that covers the ends of bones at mobile joints Anatomy of lower airway: delivers oxygen to alveoli Trachea (windpipe): conduit for air entry into the lungs; divides at the carina into two main stem bronchi, right and left Bronchioles: dilate and constrict as oxygen passes through them Small bronchioles connect to alveoli: site of oxygen and carbon dioxide exchange