9

Description:	9 Review Questions B
Category:	Anatomy
Created by:	schell912 on 2007-02-09
Stack ID:	67017

Question	Answer
All of the following are functions of muscle EXCEPT	protection
An entire skeletal muscle is surrounded by	epimysium
As an axon enters a muscle, it branches into a number of axonal terminals, each of which forms a neuromuscular junction with a single muscle fiber. A motor neuron and all the muscle fibers it supplies is called a	motor unit
During muscle contraction, all of the following occur EXCEPT	hemoglobin concentration in muscle fibers increases.
What is the ion released from the terminal cisternae that combines with troponin and removes the blocking action of tropomyosin, resulting in formation of cross bridges?	Ca2+
Each skeletal muscle fiber is controlled by a neuron at a single	neuromuscular junction
In a skeletal muscle fiber, which of the following best describes the composition of the structure known as a triad?	Terminal cisterna, transverse tubule, and terminal cisterna
In the sliding filament model of muscle contraction, the myofilaments slide over each other, resulting in an overlapping of actin and _________.	myosin
Interactions between actin and myosin filaments of the sarcomere are responsible for	muscle contraction
The all-or-none response of a muscle fiber means that	a muscle fiber responds maximally to threshold stimulation or NOT at all.
The dense layer of collagen fibers that surround an entire skeletal muscle is the	epimysium
The functional unit of a skeletal muscle fiber is the	sarcomere
Which statement below does NOT represent a role of ionic calcium in muscle contraction?	Triggers diffusion of Na+ out of the cells
The space between the neuron and the muscle is the	synaptic cleft.
The term that means a continued mild or partial contraction of an entire muscle is muscle	tone
The type of muscle contraction in which the muscle fibers produce increased tension but the muscle neither shortens nor lengthens is called	isometric.
the role of calcium ions in the contraction of skeletal muscle?	Calcium ions bind to the troponin-tropomyosin complex and remove their inhibitory action on actin/myosin interaction
the following statements about smooth muscle is true?	Fibers are small and spindle-shaped.
following statements is INCORRECT	Skeletal muscles are responsible for the pumping action of the heart.
the following substances increases in quantity during repetitive muscle contraction?	Lactic acid
The sequence of electrical changes that occurs along the sarcolemma when a muscle fiber is stimulated is known as the	action potential.
In the early stage of repolarization, the sarcolemma is restored to its initial polarized state initially by	K+ diffusing rapidly out of the muscle fiber.
During repolarization, the initial events restore only the electrical conditions while the Na+/K+ pump restores the	ionic conditions.
the following moves Ca2+ back into the tubules of the SR after a contraction?	The ATP-dependent calcium pump
the following allows recoil of the muscle fiber when contraction ends?	Elastic filaments
the following binds calcium ions in a smooth muscle causing contraction?	Calmodulin
the following events is something a smooth muscle can do but cardiac and skeletal muscle can not do?	Grow by hyperplasia or an increase in the number of cells.
the following types of muscle is found in the eye and are used to regulate the size of the pupil?	Multiunit smooth muscle
All of the following terms refer to the ability to receive and respond to a stimulus except	contractility.
Elasticity refers to the ability of a muscle fiber to	recoil and resume its resting length after being stretched.
the following muscles is voluntary?	the muscle that extends the arm at the elbow
the following are characteristics of skeletal muscle contraction except	it can contract for long periods of time without tiring.
Unlike cardiac and smooth muscle, skeletal muscle	must be stimulated by nerve endings to initiate contraction.
A sarcomere is part of a	myofibril.
The epimysium is	the overcoat of dense irregular connective tissue that surrounds the whole muscle.
the following statements about "indirect attachments" of muscle is incorrect?	The epimysium of the muscle fuses with the periosteum of the bone.
the following characteristics is not unique to skeletal muscle fibers?	They are striated
The plasma membrane of a muscle cell is known as the	sarcolemma.
"Cross bridges" that link between the thick and thin filaments are formed by the	globular head of thick filaments
The function of the protein "dystrophin" is to	links the thin filaments to integral proteins.
the following is thought to be an autoimmune disease of acetylcholine receptors?	Myasthenia gravis
The binding of acetylcholine molecules to acetylcholine receptors would lead to all of the following except	sodium would leave the muscle cell.
The refractory period in which the muscle will not contract if stimulated occurs during __________ of the muscle cell.	repolarization.
What would happen if the calcium level in the sarcoplasm was kept high?	The cell would calcify and die
What is the cause of rigor mortis	Calcium influx into the cell after death causes rigor mortis.
The difference in the speed and duration of contraction of a twitch contraction in different muscles through-out the body is due to the	enzyme variations in different muscles
the following would produce a " treppe" effect on muscle contraction?	Applying the same strength stimulus for a long period of time.
In an isotonic eccentric muscle contraction, the muscle generates force as it	increases its length
The presence of creatine phosphate in the muscle provides	additional energy to the contracting muscle
Where does 95% of the energy needed for contraction come from during moderate exercise?	ATP provides 95% of energy during moderate exercise.
The alternating contraction and relaxation of opposing layers of smooth muscle is referred to as	peristalsis
the following characteristics is unique to smooth muscle?	the absence of striations.
Cardiac muscle control is voluntary.	False
Communication between nerve and muscle fiber occurs at specialized junctions called neuromuscular junctions	True
Cross-bridges are portions of the actin molecules.	False
During the recovery period following exercise, the body's need for oxygen is increased.	True
In isotonic contractions, the muscle changes in length and the tension remains constant through most of the contractile period.	True
Lactic acid is an end product of anaerobic fermentation that causes muscle fatigue.	True
Muscles that exert very fine control (such as the muscles controlling movements of the fingers and eyes) have large motor units.	False
One of the functions of the smooth muscle tissue is to force blood from the heart into the major arteries.	False
The area of the sarcomere that contains only thin and titin elastic filaments is the I band.	True
The neurotransmitter that stimulates skeletal muscle is adrenalin.	False
The sequence of events which forms the link between electrical activity in the sarcolemma and the initiation of a contraction is called excitation-contraction coupling.	True
The skeletal muscle complex known as the triad consists of the transverse tubule and the terminal cisternae	True
The space between the neuron and the muscle is the synaptic knob.	False
The type of muscle fiber that is most resistant to fatigue is the fast fiber.	False
Cross-bridges occur when myosin combines with the active site on actin.	False
Cross bridge attachment to actin requires K+.	True
In the initial stages of repolarization the ionic conditions are restored returning the membrane to its resting potential.	False
Ca++ is essential for skeletal muscle contraction	False
Below threshold voltage only a small amount of muscle response movement occurs.	True
At maximal stimulus the muscle is contracting at full strength.	False
At maximal stimulus the muscle is contracting at full strength	True
A condition in which a muscle contracts progressively stronger due to warming is called treppe	True

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