Cross-bridge cycling

Cross-bridge cycling 4. CytoplasmicCa2+removal 5. Depolarization of 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 tetanus?

a. Adenosine triphosphate (ATP) b.$$\mathrm{K}+$$c.$$\mathrm{Na}+$$d. Troponin e.Ca2+. f. Calmodulin 7. In the contraction of gastrointestinal smooth muscle, which of the following events occurs right after binding to calmodulin? a. increased intracellular concentration b. activation of myosin light chain kinase c. depolarization of the sarcolemmal membrane d. opening of ligand-gated channels e.-induced release 8. Which autonomic receptor mediates the 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 the autonomic nervous system? a. Sympathetic and parasympathetic nervous systems are two groups of the autonomic nervous system b.

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