11.1 Types and Characteristics of Muscular Tissue

1			The ability of the muscle cell membrane to respond to stimuli with electric changes is known as ________________.
			A)	excitability
			B)	conductivity
			C)	extensibility
			D)	elasticity
2			The ability of the muscle cell to stretch under tension is known as
			A)	excitability.
			B)	conductivity.
			C)	extensibility.
			D)	elasticity.
3			The ability of the muscle cell to return to its initial length after being stretched is called
			A)	excitability.
			B)	conductivity.
			C)	extensibility.
			D)	elasticity.

11.2 Microscopic Anatomy of Skeletal Muscle

4			The elasticity of skeletal muscle fibers is primarily due to the presence of this protein.
			A)	titin
			B)	globular actin
			C)	troponin
			D)	collagen
			E)	tropomyosin
5			T tubules are extensions of the ______________ in skeletal muscle.
			A)	sarcoplasmic reticulum
			B)	sarcolemma
			C)	junctional folds
			D)	cytoskeleton
			E)	thick filament
6			Which of the following is a regulatory protein of muscle?
			A)	actin
			B)	myosin
			C)	tropomyosin
			D)	titin

11.3 The Nerve-Muscle Relationship

7			All of the following are structural components of the neuromuscular junction except
			A)	synaptic bulbs.
			B)	junctional folds.
			C)	basal lamina.
			D)	T tubules.
			E)	acetylcholine receptors.
8			Flaccid paralysis can be caused by
			A)	pesticides.
			B)	cholinesterase inhibitors.
			C)	curare.
			D)	acetylcholinesterase.
9			The resting membrane potential (RMP) for a skeletal muscle cell is
			A)	-90mV.
			B)	-30mV.
			C)	1.5mV.
			D)	12 V.

11.4 Behavior of Skeletal Muscle Fibers

10			After the power stroke has occurred during skeletal muscle contraction, what must occur in order for the acto-myosin cross-bridge to be released?
			A)	ATP must be cleaved.
			B)	Myosin must be dephosphorylated.
			C)	ATP must bind with the myosin head.
			D)	Calcium must bind with myosin.
			E)	Troponin must bind with tropomyosin.
11			The principle that states the force of contraction is dependent on the degree of stretch or contraction prior to stimulation is the
			A)	sliding filament theory.
			B)	muscle tone.
			C)	length-tension relationship.
			D)	summation principle.
12			Calcium is released from the sarcoplasmic reticulum when an action potential opens gated ion channels located in the ________________.
			A)	sarcolemma
			B)	myofilaments
			C)	myoglobin
			D)	T tubules

11.5 Behavior of Whole Muscles

13			The time lapse between the beginning of stimulus and the beginning of a twitch is called the
			A)	refractory period.
			B)	contraction phase.
			C)	relaxation phase.
			D)	latent period.
14			If you attempt to lift a heavy object but it doesn't move, what type of contraction have you performed?
			A)	concentric
			B)	eccentric
			C)	isotonic
			D)	isometric
15			The phenomenon occurring when the tension of muscle twitches progressively increase as the frequency of stimulus increases is known as
			A)	graded response.
			B)	treppe.
			C)	threshold.
			D)	tetany.

11.6 Muscle Metabolism

16			Which of the following statements about slow-twitch muscle fibers is false?
			A)	Slow-twitch muscle fibers are smaller than fast-twitch fibers.
			B)	Slow-twitch muscle fibers are anaerobic.
			C)	Slow-twitch muscle fibers are fatigue resistant.
			D)	Slow-twitch muscle fibers have abundant mitochondrion and myoglobin.
17			Fatigue can be caused by all of the following except
			A)	low acetylcholine supplies.
			B)	low pH in sarcoplasm.
			C)	excess of myoglobin.
			D)	excess of lactic acid.
18			Fast-twitch fibers
			A)	have a lot of myoglobin.
			B)	mainly synthesize ATP by aerobic respiration.
			C)	are white.
			D)	have more mitochondria.

11.7 Cardiac and Smooth Muscle

19			Smooth muscles
			A)	have Z-discs.
			B)	lack T-tubules.
			C)	contain troponin.
			D)	are multinucleate.
20			Fusiform cells are found in which muscle type?
			A)	skeletal muscles
			B)	cardiac muscles
			C)	smooth muscles