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