Chapter 10 Muscle Tissue REVIEW
Cross bridge detachment is caused by ________ binding to the myosin head.
ATP
The characteristic muscle stiffness associated with rigor mortis is due to the inability of myosin filaments to detach from the active site on actin filaments. What molecule is essential for this detachment?
ATP
When muscles are actively contracting, the process requires large amounts of energy in the form of _______.
ATP
During anaerobic glycolysis,
ATP is produced, pyruvic acid is produced, carbohydrate is metabolized, oxygen is not consumed.
the primary energy reserves found on skeletal muscle cells are:
ATP, creatine phosphate, and glycogen
Which of the following is true about the difference between cardiac muscle cells and skeletal muscle cells?
Cardiac muscle cells have intercalated discs where skeletal muscle cells do not.
what causes amyotrphic lateral sclerosis?
Lou Gehrigs disease, genetic defect though cause is unknown in 90-95% of cases
structures that help distribute the command to contract throughout the muscle fiber are called _________.
T-Tubules
Which of the following is not characteristic of smooth muscle?
The striations are due to the orderly arrangement of actin and myosin.
The soleus muscle is very red in color. Which of these statements about soleus muscle fibers is FALSE?
They are large in diameter.
Why do the disease tetanus and the normal sustained muscle contraction called tetanus share the same name?
They both eliminate the relaxation phase in the affected muscle fibers.
the boundary between adjacent sarcomeres is marked by the _________.
Z lines
the THICK filaments consist of
a helical array of myosin molecules
the THIN filaments consist of:
a pair of protein strands wound together to form chains of actin molecule
The skeletal muscle complex known as the triad consists of
a transverse tubule and two terminal cisternae.
the conducted charge in the transmembrane potential is called a(n) __________.
action potential
Creatine phosphate
acts as an energy reserve in muscle tissue.
When a skeletal muscle fiber is at rest, its ATP demands are met by __________.
aerobic metabolism of fatty acids
what causes rhabdomyolysis?
any condition that damages skeletal muscle
A(n) ________ can be described as a broad tendinous sheet.
aponeurosis
what causes polymyositis?
autoimmune disorder, may be viral, may be triggered by cancer, associated with celiac disease
the property of cardiac muscle that allows it to contract without neural stimulation is
automaticity
muscle tissues are highly specialized for producing ____________.
body movement/ contraction
The role of acetylcholinesterase is to
break down acetylcholine into acetate and choline components.
Active sites on the actin become available for binding after
calcium binds to troponin.
In response to action potentials arriving along the transverse tubules, the sarcoplasmic reticulum releases
calcium ions.
Smooth muscle contracts when calcium binds to __________ and activates __________.
calmodulin; myosin light chain kinase
Peak tension production occurs when all motor units in the muscle contract in a state of:
complete tetanus
when the calcium ion concentration in the cytoplasm prolongs the contraction state, making it continuous, the contraction is called _________.
complete tetanus
When a muscle is stimulated repeatedly at a high rate, the amount of tension gradually increases to a steady maximum tension. This state of maximum tension is called
complete tetanus.
Muscle tissue, one of the four basic tissue groups, consists chiefly of cells that are highly specialized for
contraction.
troponin and tropomyosin are two proteins that can prevent the contractile process by
covering the active site and blocking the actin-myosin interaction
because they connect think and thin filaments, the myosin heads are also known as ________.
cross-bridges
in an ISOTONIC contraction
crossbridges must produce enough tension to overcome the resistance
what causes Mitochondrial myopathis
damage to mitochondria, genetic, mutations in genes
what causes Duchenne muscular dystrophy?
defective gene for dystrophin, typically only in males
After contraction, a muscle fiber returns to its original length through:
elastic forces and the movement of opposing muscles
The delicate connective tissue that surrounds the skeletal muscle fibers and ties adjacent muscle fibers together is the
endomysium.
the amount of time for which the individual can perform a particular activity is refered to as __________.
endurance
The dense layer of connective tissue that surrounds an entire skeletal muscle is the
epimysium
the dense layer of collagen fibers surrounding a muscle is called the ___________.
epimysium
the 3 layers of connective tissue compressing each muscle are the:
epimysium, perimysium, and endomysium
what are the 3 layers of connective tissues that are part of each muscle?
epimysium, perimysium, and endomysium
muscle tissue consists of cells that are highly specialized for the function of:
excitability, contraction, and extensibility
When Ca++ binds to troponin, it produces a change by:
exposing the active site on the thin filaments
bundles of muscle fibers are called _______.
fascicles
the type of skeletal muscle fibers that have low fatigue resistance are:
fast fibers
Large-diameter, densely packed myofibrils, large glycogen reserves, and few mitochondria are characteristics of
fast fibers.
why do fast fibers fatigue more rapidly than slow fibers?
fast fibers: powerful contractions, use ATP in massive amounts, few mitochondria slow fibers: specialized for extended periods, extensive capillaries, and myoglobin
Which of the following is not a function of smooth muscle tissue?
forcing blood from the heart into the major arteries
what causes myotubular myopathy?
genetic, X-linked trait, nuclei abnormally located
What is fibrodysplasia ossificans progressiva?
genetic: affects gene that regulates ossification, ACVR1 gene
a skeletal muscle continues to contract even when mitochondrial activity is limited by the availability of oxygen due to the process of _________.
glycolysis
Which of the following allows muscles to return to their original shape during relaxation?
gravity, opposing muscle contractions, and elastic forces
A fascicle is a
group of muscle fibers that are encased in the perimysium.
Cardiac muscles cells have a sarcolemma that is more permeable to calcium, which causes them to __________.
have contractions that last longer than skeletal muscle fibers
Fast fibers
have low resistance to fatigue and quick twitches.
Which of the following is not an effect of aging on the muscular system?
hypertrophy
a muscle producing peak tension during rapid cycles of contraction and relaxation is said to be in ________.
incomplete tetanus
the process of reaching complete tetanus is obtained by:
increasing the rate of stimulation until the relaxation phase is completely eliminated
muscle contraction occurs as a result of:
interactions between the thick and thin filaments of the sarcomere
The type of contraction in which the muscle fibers do not shorten is called
isometric
what are the differences between an isometeric and an isotonic contraction?
isometric: tension without shortening isotonic: tension with change in length
Structurally, smooth muscle cells differ from skeletal muscle cells because smooth muscle cells
lack of myofibrils and sarcomeres
at peak activity levels, most of the ATP is provided by glycolysis, leading to production of __________.
lactic acid
Muscle fatigue occurs because of a buildup of __________ and a(n) __________ in pH.
lactic acid; decrease
the reason there is less precise control over leg muscles compared to muscles of the eye is
many muscle fibers are controlled by a single motor neuron
Bacteria that cause tetanus release a neurotoxin. Which of the following components of the neuromuscular junction (NMJ) does this neurotoxin affect directly?
motor neurons
all of the muscle fibers controlled by a sing
motor unit
an indication of how fine the control movement can be is determined by the size of the ______.
motor unit
A single motor neuron together with all the muscle fibers it innervates is called a(n)
motor unit.
Interactions between actin and myosin filaments of the sarcomere are responsible for
muscle contraction.
Skeletal muscle fibers are formed from embryonic cells called
myoblasts.
Thick filaments are made of the protein
myosin.
Each skeletal muscle fiber is controlled by a motor neuron at a single
neuromuscular junction.
the amount of oxygen used in the recovery period to restore normal pre-exertion conditions is referred to as ___________.
oxygen debt
the timing of contractions in cardiac muscle tissues is determined by specialized muscle fibers called ___________ cells.
pacemaker
what causes fibromyalgia?
physical or emotional trauma, sleep disturbances, infection or virus
Resting smooth muscle can be stretched without affecting tension development because of its __________.
plasticity
The ability of smooth muscle to function over a wide range of lengths is called
plasticity
the ability of smooth muscle to function over a wide range of lengths is called ______.
plasticity
Which of the following is a recognized function of skeletal muscle?
produce movement, maintain body temperature, guard body entrances and exits, maintain posture
the primary functions performed by the skeletal muscles is (are):
produce skeletal movement, to guard entrances and exits, and to maintain body temp
skeletal muscles move the body by:
pulling on the bones of the skeleton
Skeletal muscle does each of these EXCEPT __________.
pump blood
The increase in muscle tension that is produced by increasing the number of active motor units is called
recruitment
the smooth but steady increase in muscular tension produced by increasing the number of active motor unites is called _________.
recruitment
muscles dominated by slow fibers are sometimes referred to as
red muscles
A patient takes a medication that blocks ACh receptors of skeletal muscle fibers. What is this drug's effect on skeletal muscle contraction?
reduces the muscle's ability for contraction
After death, muscle fibers run out of ATP and calcium begins to leak from the sarcoplasmic reticulum into the sarcoplasm. This results in a condition known as
rigor mortis.
The plasma membrane of a skeletal muscle fiber is called the
sarcolemma
the cell membrane that surrounds the cytoplasm of a muscle fiber is called the ________.
sarcolemma
The repeating unit of a skeletal muscle fiber is the
sarcomere
the smallest functional unit of the muscle fiber is:
sarcomere
muscle cells contain contractible unites called ________
sarcomeres
Stem cells located between the endomysium and sarcolemma that function in the repair of damaged muscle tissue are called
satellite cells.
what is zenkers degeneration?
severe infections such as typhoid or electrical burns, toxemia
Since each myofibril is attached at either end of the muscle fiber, when sarcomeres shorten, the muscle fiber
shortens.
Which type of muscle tissue has the greatest effect on the body's heat production?
skeletal
by controlling the number of activated muscle fibers, you can control the amount of tension produced by the _________.
skeletal muscles
The structural theory that explains how a muscle fiber contracts is called the ________ theory.
sliding filament
The type of muscle fiber that is most resistant to fatigue is the ________ fiber.
slow
Which skeletal muscle fiber type slow or fast contains more mitochondria?
slow
Extensive blood vessels, mitochondria, and myoglobin are found in the greatest concentration in:
slow fibers
Which of the following types of muscle fibers are best adapted for prolonged contraction such as standing all day?
slow fibers
spindle shaped cells with a single, centrally located nucleus are characteristic of ___________.
smooth muscle
in the digestive and urinary systems, the rings of smooth muscle that regulate the movement of materials along internal passageways are called ___________.
sphincters
what causes compartment syndrome?
swelling from trauma: car accident, cash injury, fractures, surgery
The narrow space between the synaptic terminal and the muscle fiber is the
synaptic cleft.
the dense regular connective tissue that attaches skeletal muscle to bones is known as the _________.
tendon
At each end of the muscle, the collagen fibers of the epimysium, perimysium, and endomysium, come together to form a
tendon.
the interactions between the thick and the thin filaments produce __________.
tension
in an ISOMETRIC contraction
tension rises but the length of the muscle remains constant
Which of the following hormones directly stimulates growth of muscle tissue, leading to increased muscle mass?
testosterone
A muscle produces its highest tension when in complete
tetanus
Mitochondrial activities are relatively efficient, but their rate of ATP generation is limited by the:
the availability of oxygen
the maintenance of normal body temperature is dependent upon:
the production of energy by muscles
the tension in a muscle fiber will vary depending on
the structure of individual sarcomeres, the initial length of muscle fibers, and the number of cross bridges within a muscle fiber
the sliding filament theory explains that the physical change that takes place during contraction is
the thin filaments are sliding toward the center of the sacromere alongside the thick filaments
skeletal muscles are often called voluntary muscles because:
they contract when stimulated by motor neurons of the central nervous system
the "staircase" phenomenon during which the peak muscle tension rises in stages is called ________.
treppe
At rest, active sites on the actin are blocked by
tropomyosin molecules.
active site exposure during the contraction process occurs when calcium binds to
troponin
At rest, the tropomyosin molecule is held in place by
troponin molecules.
a single stimulus contraction relaxation sequence in a muscle fiber is a __________.
twitch
Each thin filament consists of
two actin protein strands coiled helically around each other.
muscles dominated by fast fibers are sometimes referred to as
white muscles
what are the five functions performed by skeletal muscles?
1. producing movement 2. maintaining posture & body position 3. supporting soft tissues 4. guarding body entrances & exits 5. maintaining body temp
Part complete Put the following structures in order from superficial to deep. 1. muscle fiber 2. perimysium 3. myofibril 4. fascicle 5. endomysium 6. epimysium
6, 2, 4, 5, 1, 3 epimysium, perimysium, fascicle, endomysium, muscle fiber, myofibril
