Muscle Physiology Quiz

Study Flashcards Play Quiz

Questions and Answers

Smooth muscle can be stimulated to contract by which of the following?

All of the above

Where is smooth muscle found?

In the walls of hollow organs

Which type of smooth muscle contracts coordinately because the cells are linked by gap junctions?

Unitary smooth muscle

Which protein controls the interaction of actin and myosin in smooth muscle?

Calmodulin Signup and view all the answers

What regulates myosin-light-chain kinase in smooth muscle?

Ca2+ Signup and view all the answers

Which type of smooth muscle has little or no coupling between cells?

Multiunit smooth muscle Signup and view all the answers

What is required to cause smooth muscle relaxation?

Calcium pump Signup and view all the answers

Which type of muscle fiber is densely innervated by postganglionic fibers of the parasympathetic and sympathetic nervous systems?

Smooth muscle fiber Signup and view all the answers

Smooth muscle contraction depends on the concentration of which ion in the extracellular fluid?

Calcium ion Signup and view all the answers

How long does a single smooth muscle contraction typically last?

Seconds Signup and view all the answers

Which type of muscle is made up of cells called muscle fiber or myocyte?

Skeletal muscle Signup and view all the answers

What percentage of the body is composed of skeletal muscle?

40% Signup and view all the answers

What is the diameter range of muscle fibers in skeletal muscles?

10-100 micrometers Signup and view all the answers

What is the function of transverse tubules (T tubules) in skeletal muscle fibers?

To store calcium ions Signup and view all the answers

What is the role of titin in skeletal muscle?

To provide structural support Signup and view all the answers

What is the thinnest filament in a sarcomere?

Actin filament Signup and view all the answers

What is the function of the sarcoplasmic reticulum (SR) in skeletal muscle?

To store and release calcium ions Signup and view all the answers

What is the role of myofibrils in skeletal muscle fibers?

To contract and produce force Signup and view all the answers

What is the function of the sarcolemma in skeletal muscle fibers?

To transmit electrical impulses Signup and view all the answers

What is the smallest unit of a myofibril that has the ability to contract?

Sarcomere Signup and view all the answers

Which proteins make up the thin filaments in skeletal muscle?

Actin, Tropomyosin, and Troponin Signup and view all the answers

What protein anchors the entire myofibrillar array to the cell membrane?

Dystrophin Signup and view all the answers

What is the term for all the muscle fibers innervated by a single nerve fiber?

Motor unit Signup and view all the answers

What triggers the release of calcium ions from the sarcoplasmic reticulum in skeletal muscle?

Activation of the ryanodine receptors Signup and view all the answers

What is the main source of energy for muscle contraction in the first few seconds?

ATP Signup and view all the answers

What happens to the tension in a contracting muscle as the actin and myosin filaments overlap?

The tension increases progressively Signup and view all the answers

In smooth muscle, what serves the same role as the Z disks in skeletal muscle?

Dense bodies Signup and view all the answers

What allows smooth muscle cells to contract as much as 80% of their length?

Actin filaments Signup and view all the answers

What is the name of the protein that binds up to 40 calcium ions in the sarcoplasmic reticulum?

Calsequestrin Signup and view all the answers

What happens to the tension in a contracting muscle as the sarcomere shortens?

The tension increases progressively Signup and view all the answers

Which type of muscle makes up about 40% of the body?

Skeletal muscle Signup and view all the answers

What is the diameter range of muscle fibers in skeletal muscles?

10-80 micrometers Signup and view all the answers

What is the function of the sarcolemma in skeletal muscle fibers?

To enclose the muscle fiber Signup and view all the answers

What is the name of the thin membrane enclosing a skeletal muscle fiber?

Sarcolemma Signup and view all the answers

What is the function of transverse tubules (T tubules) in skeletal muscle fibers?

To transmit action potentials deep into the muscle fiber Signup and view all the answers

What surrounds the myofibrils in skeletal muscle fibers?

Sarcoplasmic reticulum Signup and view all the answers

What is the most small unit of the myofibril that has the ability to contract?

Sarcomere Signup and view all the answers

What protein keeps the myosin and actin filaments in place in skeletal muscle?

Titin Signup and view all the answers

What is the function of the sarcoplasmic reticulum (SR) in skeletal muscle?

To store calcium ions Signup and view all the answers

What are skeletal muscles composed of?

Muscle fibers Signup and view all the answers

Which type of muscle contracts coordinately because the cells are linked by gap junctions?

Unitary smooth muscle Signup and view all the answers

What is the main source of energy for muscle contraction in smooth muscle?

ATP Signup and view all the answers

Where is smooth muscle found?

Digestive system Signup and view all the answers

What regulates myosin-light-chain kinase in smooth muscle?

Calmodulin Signup and view all the answers

What is the function of the sarcoplasmic reticulum (SR) in skeletal muscle?

To store and release calcium ions Signup and view all the answers

What is the diameter range of muscle fibers in skeletal muscles?

1-10 micrometers Signup and view all the answers

What happens to the tension in a contracting muscle as the actin and myosin filaments overlap?

Tension increases Signup and view all the answers

What is the function of transverse tubules (T tubules) in skeletal muscle fibers?

To transmit action potentials Signup and view all the answers

What is the role of myofibrils in skeletal muscle fibers?

To contract muscle fibers Signup and view all the answers

What happens to the tension in a contracting muscle as the sarcomere shortens?

Tension increases Signup and view all the answers

What is the role of dystrophin in skeletal muscle?

Anchoring the myofibrillar array to the cell membrane Signup and view all the answers

What triggers the release of acetylcholine (ACh) at the neuromuscular junction?

Nerve impulse reaching the neuromuscular junction Signup and view all the answers

What protein is responsible for carrying depolarization from the muscle cell surface to the interior of the fiber?

Dihydropyridine receptor (DHPR) Signup and view all the answers

What triggers the release of calcium ions from the sarcoplasmic reticulum in skeletal muscle?

Activation of the dihydropyridine receptor (DHPR) Signup and view all the answers

What is the main source of energy for muscle contraction in the first few seconds?

ATP Signup and view all the answers

What is the function of calsequestrin in the sarcoplasmic reticulum?

Binding up to 40 calcium ions Signup and view all the answers

What allows smooth muscle cells to contract as much as 80% of their length?

Actin filaments attached to dense bodies Signup and view all the answers

What protein controls the interaction of actin and myosin in smooth muscle?

Myosin-light-chain kinase Signup and view all the answers

What is the role of the sarcolemma in skeletal muscle fibers?

Cell membrane of the muscle fiber Signup and view all the answers

What is the function of the sarcoplasmic reticulum (SR) in skeletal muscle?

Regulating the release and reaccumulation of calcium ions Signup and view all the answers

Study Notes

Smooth Muscle

Can be stimulated to contract by various factors
Found in walls of hollow organs and tubes, such as blood vessels, digestive tract, and airways
Unitary smooth muscle contracts coordinately due to gap junctions between cells
Calmodulin controls the interaction of actin and myosin
Myosin-light-chain kinase is regulated by calcium and calmodulin
Multiunit smooth muscle has little or no coupling between cells
Relaxation requires a decrease in calcium ion concentration
Dense innervation by postganglionic fibers of the parasympathetic and sympathetic nervous systems
Contraction depends on extracellular calcium ion concentration
A single contraction typically lasts around 1-5 seconds

Skeletal Muscle

Composed of cells called muscle fibers or myocytes
Makes up around 40% of the body
Muscle fibers have a diameter range of 10-100 μm
Transverse tubules (T-tubules) rapidly transmit the action potential to the interior of the fiber
Titin plays a role in muscle contraction and relaxation
The thinnest filament in a sarcomere is actin
Sarcoplasmic reticulum (SR) is the site of calcium ion storage and release
Myofibrils are the contractile units of skeletal muscle fibers
Sarcolemma is the plasma membrane of a muscle fiber
A sarcomere is the smallest unit of a myofibril that can contract
Thin filaments are composed of actin, tropomyosin, and troponin
Dystrophin anchors the entire myofibrillar array to the cell membrane
A motor unit is all the muscle fibers innervated by a single nerve fiber
Action potential triggers the release of calcium ions from the SR
Main source of energy for muscle contraction in the first few seconds is ATP and PCr
Tension decreases as the actin and myosin filaments overlap
Smooth muscle cells can contract up to 80% of their length due to the absence of Z-disks
Calsequestrin binds up to 40 calcium ions in the SR
Tension increases as the sarcomere shortens

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Muscle Physiology Quiz

Questions and Answers

Smooth muscle can be stimulated to contract by which of the following?

Where is smooth muscle found?

Which type of smooth muscle contracts coordinately because the cells are linked by gap junctions?

Which protein controls the interaction of actin and myosin in smooth muscle?

What regulates myosin-light-chain kinase in smooth muscle?

Which type of smooth muscle has little or no coupling between cells?

What is required to cause smooth muscle relaxation?

Which type of muscle fiber is densely innervated by postganglionic fibers of the parasympathetic and sympathetic nervous systems?

Smooth muscle contraction depends on the concentration of which ion in the extracellular fluid?

How long does a single smooth muscle contraction typically last?

Which type of muscle is made up of cells called muscle fiber or myocyte?

What percentage of the body is composed of skeletal muscle?

What is the diameter range of muscle fibers in skeletal muscles?

What is the function of transverse tubules (T tubules) in skeletal muscle fibers?

What is the role of titin in skeletal muscle?

What is the thinnest filament in a sarcomere?

What is the function of the sarcoplasmic reticulum (SR) in skeletal muscle?

What is the role of myofibrils in skeletal muscle fibers?

What is the function of the sarcolemma in skeletal muscle fibers?

What is the smallest unit of a myofibril that has the ability to contract?

Which proteins make up the thin filaments in skeletal muscle?

What protein anchors the entire myofibrillar array to the cell membrane?

What is the term for all the muscle fibers innervated by a single nerve fiber?

What triggers the release of calcium ions from the sarcoplasmic reticulum in skeletal muscle?

What is the main source of energy for muscle contraction in the first few seconds?

What happens to the tension in a contracting muscle as the actin and myosin filaments overlap?

In smooth muscle, what serves the same role as the Z disks in skeletal muscle?

What allows smooth muscle cells to contract as much as 80% of their length?

What is the name of the protein that binds up to 40 calcium ions in the sarcoplasmic reticulum?

What happens to the tension in a contracting muscle as the sarcomere shortens?

Which type of muscle makes up about 40% of the body?

What is the diameter range of muscle fibers in skeletal muscles?

What is the function of the sarcolemma in skeletal muscle fibers?

What is the name of the thin membrane enclosing a skeletal muscle fiber?

What is the function of transverse tubules (T tubules) in skeletal muscle fibers?

What surrounds the myofibrils in skeletal muscle fibers?

What is the most small unit of the myofibril that has the ability to contract?

What protein keeps the myosin and actin filaments in place in skeletal muscle?

What is the function of the sarcoplasmic reticulum (SR) in skeletal muscle?

What are skeletal muscles composed of?

Which type of muscle contracts coordinately because the cells are linked by gap junctions?

What is the main source of energy for muscle contraction in smooth muscle?

Where is smooth muscle found?

What regulates myosin-light-chain kinase in smooth muscle?

What is the function of the sarcoplasmic reticulum (SR) in skeletal muscle?

What is the diameter range of muscle fibers in skeletal muscles?

What happens to the tension in a contracting muscle as the actin and myosin filaments overlap?

What is the function of transverse tubules (T tubules) in skeletal muscle fibers?

What is the role of myofibrils in skeletal muscle fibers?

What happens to the tension in a contracting muscle as the sarcomere shortens?

What is the role of dystrophin in skeletal muscle?

What triggers the release of acetylcholine (ACh) at the neuromuscular junction?

What protein is responsible for carrying depolarization from the muscle cell surface to the interior of the fiber?

What triggers the release of calcium ions from the sarcoplasmic reticulum in skeletal muscle?

What is the main source of energy for muscle contraction in the first few seconds?

What is the function of calsequestrin in the sarcoplasmic reticulum?

What allows smooth muscle cells to contract as much as 80% of their length?

What protein controls the interaction of actin and myosin in smooth muscle?

What is the role of the sarcolemma in skeletal muscle fibers?

What is the function of the sarcoplasmic reticulum (SR) in skeletal muscle?

Study Notes

Smooth Muscle

Skeletal Muscle

Studying That Suits You

More Quizzes Like This

Muscle Physiology: Skeletal Muscle Structure

Physiology Class 7: Contraction of Skeletal Muscle

Muscle Physiology - Skeletal Muscle Structure

Muscle Physiology: Skeletal Muscle Lecture 3