chapter 10 Muscle tissue
A neuromuscular junction contains a_____
-Synaptic cleft -Motor end plate -Synaptic knob
Which are characteristics of oxidative fibers?
-Use aerobic respiration -Good for endurance -Red -High concentration of myoglobin
Which of the following will remain a fixed length during contraction?
A band
Muscle fiber
A muscle cell
Multiunit smooth muscle cells are stimulated ______
Individually
Skeletal
Long,cylindrical fiber
Although muscle fibers obey the all or none principle, the force of muscle contraction can be carried depending on how many _____units are used
Motor
Which of the following must occur before relaxation can begin?
Removal of ACh at the NMJ by acetylcholinesterase
Under the light microscope, the dark (A) bands observed in skeletal muscle contain ______ filaments
thick and thin
Smooth muscle is found in which of the following locations?
-Around blood vessels -In the wall of the small intestine -In the wall of the uterus
Multiunit smooth muscle is found in which of the following locations?
-Arrector pili muscles in the skin -Iris of the eye
Which can cause muscle fatigue?
-Na+ or K+ imbalances -Insufficient Ca2+ -Build up of intracellular Pi
The skeletal muscles arranged in layers along the walls of the abdominal cavity and the floor of the pelvic cavity perform what function?
-Protection -Compression -Contraction -Support
In which activities are muscles in an isometric contraction?
-Pushing on a locked door -Sitting up very straight -Holding a yoga pose
Acetylcholinesterase in the synaptic cleft is needed so that ____will not continuously stimulate the cell to contract.
ACh
The arrival of a nerve impulse at the synaptic knob of a motor neuron causes synaptic vesicles to release _____ into the synaptic cleft
ACh
In a neuromuscular junction, what enzyme breaks down acetylcholine?
AChE
ACh is an acronym for
Acetylcholine
Thin filaments in a smooth muscle cells contain which proteins?
Actin, Tropomyosin
Long Term
Aerobic Respiration
Short term
Anaerobic Respiration
In a muscle cell, the short term energy is supplied by ____respiration, while long term energy is supplied by_____
Anaerobic/Aerobic
Which of the following can stimulate contraction of a smooth muscle?
Any of these -Hormones -stretch -low pH -CO2
After breaking your arm, you have a cast on it for three months. When the cast is removed, your arm looks much smaller than it did before. What process caused this to happen?
Atrophy
The connective tissue layers in muscle provide: protection,distribution sites for blood vessels and nerves and a means of_____ to the skeleton
Attachment
Which of the following characteristics is associated with better anaerobic capacity?
Better capacity to form lactic acid
The cell bodies of motor neurons that stimulate skeletal muscles cells are located in the
Brain or spinal cord
The sarcoplasmic reticulum stores ____ions needed to initiate muscle contraction
Calcium
Sarcoplasm in a resting muscle fiber contains which of the following except:
Calcium ions
In addition to skeletal muscle, two other types of muscle are found in the body: ______ muscle and ______ muscle
Cardiac, Smooth
The sarcolemma of smooth muscle has small invaginations called______
Caveolae
As a result of muscle fiber contraction, thick filaments in neighboring sarcomeres move____
Closer together
Posture
Contraction of specific skeletal muscles stabilizes joints
Immediate
Creatine Phosphate
For a muscle's short term energy needs, once ATP is exhausted,
Creatine phosphate replenishes ATP
Sarcoplasm
Cytoplasm of a muscle fiber
The amount of additional oxygen that must be inhaled in order to restore pre-exercise levels is called oxygen ____
Debt
A person's tolerance for exercise _____with age.
Decreases
Anchoring point between intermediate filaments and the sarcoplasm
Dense Body
Which of these cellular elements is found only in smooth muscle?
Dense bodies
The epimysium of a muscle is composed of ____connective tissue
Dense irregular
Anchoring point between intermediate filaments and the sarcolemma
Dense plaque
A sarcomere is defined as the distance from one Z _____to the next
Disc
After contraction, muscle returns to its original relaxed position due to it's natural_____
Elasticity
Which of these terms refers to the ability of muscles to return to their resting length after stretching?
Elasticity
Which of the following happens NEXT after stimulation of a muscle cell at a neuromuscular junction?
Electrical current travels down T tubules
Muscle cell
Endomysium
The connective tissue element that wraps around individual myfiber is
Endomysium
Muscle
Epimysium
Muscle cells are said to have what characteristic because they can respond to stimulation from the nervous system?
Excitability
Intermediate fibers have a high resistance to
Fatigue
Smooth
Fusiform-shaped cell
An increase in muscle fiber size is called _______
Hypertrophy
Cytoskeleton network
Intermediate filaments
Smooth muscle contraction is under ______control of the nervous system
Involuntary
During an____contraction, the length of the muscle does not change.
Isometric
The motor neuron transmits the effect of a nerve impulse to the muscle fiber at a neuromuscular
Junction
The ______ line is a thin, transverse, protein meshwork structure in the center of the H zone of a sarcomere
M
In a motor unit, a single ____neuron typically controls numerous muscle fibers in a muscle.
Motor
Skeletal muscle contraction is controlled by ____neurons
Motor
The type of smooth muscle found in large arteries is
Multi unit smooth muscle
Body movement
Muscles contract and pull on the tendons that attach the muscles to the bones
A group of heredity diseases in which skeletal muscles degenerate and are replace with adipose:
Muscular dystrophy
During development, many groups of _____fuse to form single skeletal muscles fibers
Myoblasts
Myofibrils are made of
Myofilaments
Thick myofilaments are composed of bundles of what protein molecule?
Myosin
T-tubule
Narrow, tubular extensions of the sarcolemma in the sarcoplasm
Fascicle
Perimysium
ATP is generate when the enzyme creatine kinase transfers Pi from creatine ______ to ADP
Phosphate
Sarcolemma
Plasma membrane of a muscle fiber
At rest, the sarcoplasm has a relatively higher concentration of
Potassium
As you hold a barbell and begin to flex your arm in a curl, your biceps brachii slowly lifts the weight by using more and more motor units. This phenomenon, which increases the strength of the contraction, is referred to as
Recruitment
The plasma membrane of a skeletal muscle fiber is called the
Sacolemma
Calcium in a resting muscle cell is contained in
Sarcoplasmic reticulum
Cardiac
Short,branched cell
In an isotonic contraction, the muscle fibers___,resulting in movement.
Shorten or lengthen
The_____filament theory explains how muscle fibers shorten during contraction
Sliding
this is the name of our model of how much muscles contract
Sliding filament
What type of muscle forms the majority of the walls of the digestive tract?
Smooth
Sarcoplasmic Reticulum
Smooth endoplasmic reticulum in a muscle fiber
Although smooth muscle cells have both thick and thin filaments, they are not precisely aligned, so no visible_____are present.
Striations
The motor end plate has folds and indentations to increase the membranes surface area adjacent to the______
Synaptic Knob
A cord like structure that attaches muscle to bone is a____
Tendon
Relaxation Period
Tension decreases
Contraction period
Tension increases
When calcium ions bind to troponin, which of the following then occur?
The myosin binding sites on actin are exposed
Latent period
There is no tension
The H-band (or H-zone) is more lightly shaded because only_____filaments are present
Thick
Myofibrils are composed of
Thick and thin myofilaments
The minimum voltage necessary to produce a visible contraction in a muscle experiment is called
Threshold
A step wise increase in the force of contraction of a single muscle fiber or motor unit due to repeated stimulation with out an increase or frequency of stimulation is called
Treppe
Within a myofibril, each______shortens as the muscle fiber contracts
Sarcomere
When a muscle fiber is in a relaxed state, the_____ molecules cover the G-actin active sites, preventing interaction between thick filaments and thin filaments
Tropomyosin
T/F: A byproduct of anaerobic respiration is lactic acid
True
T/F: If a muscle is stretched too much, the contraction will be very weak.
True
T/F: Stimulating the nerve with higher voltage in a muscle experiment results in stronger contractions because of recruitment of more motor units
True
The term that indicates that skeletal muscle is under the conscious control is
Voluntary
Storage and movement of materials
Voluntary sphincter muscles of the gastrointestinal and urinary tracts can be kept closed or opened
The synaptic knob of the neuron is an ____of an axon
Expanded tip
Smooth muscle is composed of short cells that have a ___shape
Fusiform
Temperature regulation
Heat is produced as a waste product of energy usage
Tension development while shortening is called
Concentric
Correct order of occurrence once ACh diffuses across the synaptic cleft of a NMJ:
1. ACh binds to receptors on the motor end plate. 2. The resulting action potential moves down the sarcolemma 3. The action potential moves down the t-tubules 4.The action potential reaches the reminal cisternae of the SR. 5.Calcium ions are released into the sarcoplasm
Stages of cross-bridge cycling in order:
1. Calcium binds troponin; myosin binding site uncovered 2. Cross-bridge formation 3. Power stroke 4. Release of myosin head by ATP 5. Reset of myosin head
Neuromuscular junction in order
1.Arrival of nerve signal at synaptic knob 2. Calcium entry into synaptic knob 3. Exocytosis of ACh into synaptic cleft 4. Binding of ACh to motor end plate