Cross-bridge cycling

Cross-bridge cycling 4. CytoplasmicCa2+removal 5. Depolarization of$$\mathrm{T}$$tubules a. 1-2-5-3-4 b. 1-5-2-3-4 – c. 5-4-3-1-2 d. 5-4-1-3-2 e. 4-5-1-3-2 6. Repeated stimulation of a skeletal muscle fiber causes a sustained contraction (tetanus). Accumulation of which solute in intracellular fluid is responsible for the tetanus?

a. Adenosine triphosphate (ATP) b.$$\mathrm{K}+$$c.$$\mathrm{Na}+$$d. Troponin e.Ca2+. f. Calmodulin 7. In contraction of gastrointestinal smooth muscle, which of the following events occurs right after binding ofCa2+to calmodulin? a. increased intracellularCa2+concentration b. activation of myosin light chain kinase c. depolarization of the sarcolemmal membrane d. opening of ligand-gatedCa2+channels e.Ca2+-inducedCa2+release 8. Which autonomic receptor mediates secretion of epinephrine by the adrenal medulla?

a. Cholinergic nicotinic receptor b. Adrenergic alpha 1 receptor c. Adrenergic beta 2 receptor d. Adrenergic beta 1 receptor e. Cholinergic muscarinic receptor 9. Which of the following statement is not true about autonomic nervous system? a. Sympathetic and parasympathetic nervous system are two groups of the autonomic nervous system b.

Preganglionic nerve axon synapse with postganglionic nerve at ganglion c. Preganglionic nerve of sympathetic and parasympathetic release acetylcholine that binds nicotinic receptor on the ganglion d. Postganglionic nerve of sympathetic and parasympathetic release acetylcholine that binds muscarinic receptor on a target tissue e. Adrenal medulla is part of sympathetic nervous system