BIO 251 EXAM 3 STUDY GUIDE

BIO 251 EXAM 3 STUDY GUIDEA muscle fiber can be innervated by multiple motor neurons. a) True b) False f The contraction time of a skeletal muscle is the time between initiation of stimulation and peak contraction of the muscle. a) True b) False f During contraction of all types of muscle cells, Ca++ initiates contraction by entering the cytoplasm of the muscle cell by the process of facilitated diffusion. a) True b) False t The plateau phase of the contractile cell action potential is caused by Na+ entering the cell. a) True b) False f The radii of arterioles can be adjusted independently to variably distribute cardiac output among organs. a) True b) False t Platelets contain actin and myosin. a) True b) False t Ischemic heart disease is a) Rapid but regular depolarizations and contractions b) Rapid irregular uncoordinated depolarizations contractions c) Action potentials not conducted between atria and ventricles d) Over excitation of non-SA node autorhythmic regions of heart e) Reduced blood supply to heart e The steps of synaptic transmission at a neuromuscular junction are listed below, out of order. Choose the correct order. 1. Acetylcholine binds to receptors on muscle cell. 2. Acetylcholine is released. 3. A graded potential is produced on the motor end plate. 4. An action potential is produced on the muscle cell membrane.