Muscle Anatomy and Physiology Quiz

<p>Sarcomere (B)</p> Signup and view all the answers

<p>Actin (D)</p> Signup and view all the answers

<p>They are the attachment points for the thin filaments (B)</p> Signup and view all the answers

<p>By actively sliding along the actin filaments (B)</p> Signup and view all the answers

<p>The sarcomeres would be shorter and the Z lines would be closer together (B)</p> Signup and view all the answers

<p>To conduct the action potential deep into the muscle fiber. (D)</p> Signup and view all the answers

<p>To release calcium ions (Ca2+) into the cytoplasm. (B)</p> Signup and view all the answers

<p>To bind calcium ions (Ca2+) and move tropomyosin. (D)</p> Signup and view all the answers

<p>The sarcoplasmic reticulum (SR) pumps calcium ions (Ca2+) back into its lumen. (A)</p> Signup and view all the answers

<p>To transport calcium ions (Ca2+) back into the SR lumen. (C)</p> Signup and view all the answers

<p>Calcium ions (Ca2+) are released from the sarcoplasmic reticulum. (D)</p> Signup and view all the answers

<p>Larger motor units control faster, fatiguable muscle fibers. (C)</p> Signup and view all the answers

<p>By varying the frequency of action potentials sent to the motor neuron. (D)</p> Signup and view all the answers

<p>To activate the calcium pumps in the sarcoplasmic reticulum. (D)</p> Signup and view all the answers

<p>Through the propagation of the action potential along its plasma membrane and T tubules. (D)</p> Signup and view all the answers

<p>The amount of ATP available in the muscle fiber. (B)</p> Signup and view all the answers

<p>Recruitment (C)</p> Signup and view all the answers

<p>A twitch is a single, brief contraction, while a tetanus is a sustained contraction. (B)</p> Signup and view all the answers

<p>Ca2+ binds to troponin, causing a conformational change that exposes myosin binding sites on actin. (D)</p> Signup and view all the answers

<p>Slow-twitch oxidative fibers (A)</p> Signup and view all the answers

<p>All of the above. (D)</p> Signup and view all the answers

<p>Decreased activity of the Ca2+ pumps in the sarcoplasmic reticulum. (B), Decreased uptake of Ca2+ into the sarcoplasmic reticulum. (D)</p> Signup and view all the answers

<p>It replenishes ATP stores by transferring phosphate from creatine phosphate to ADP. (C)</p> Signup and view all the answers

<p>Increased Ca2+ concentration initially causes an increase in tension, but it plateaus at a certain point. (D)</p> Signup and view all the answers

<p>They conduct action potentials from the sarcolemma to the interior of the muscle fiber. (C)</p> Signup and view all the answers

<p>ATP is required for both the binding and detachment of the myosin head from actin. (B)</p> Signup and view all the answers

<p>Glycolytic System (C)</p> Signup and view all the answers

<p>Lactic Acid (A)</p> Signup and view all the answers

<p>It requires a constant supply of oxygen to function. (A)</p> Signup and view all the answers

<p>It provides a rapid source of ATP for immediate use. (D)</p> Signup and view all the answers

<p>Insufficient oxygen delivery to the muscles (D)</p> Signup and view all the answers

<p>They contract and relax to pull on bones, which are connected to joints. (B)</p> Signup and view all the answers

<p>Gap junctions allow for the rapid transmission of action potentials between cardiac muscle cells, synchronizing their contractions. (D)</p> Signup and view all the answers

<p>Smooth muscle cells are small and spindle-shaped, lacking striations, and are responsible for involuntary contractions in the walls of internal organs. (C)</p> Signup and view all the answers

<p>Smooth muscle cells lack striations, while skeletal muscle cells have a striated appearance. (C)</p> Signup and view all the answers

<p>The sarcoplasmic reticulum releases calcium ions, which bind to troponin, exposing the myosin binding sites on actin. (B)</p> Signup and view all the answers

Type of muscle under voluntary control for movement.

A long, cylindrical cell of skeletal muscle that contains multiple nuclei.

Bundles of contractile proteins within muscle fibers, organized into sarcomeres.

The basic unit of contraction in a muscle, made of actin and myosin filaments.

Thin filaments in muscle fibers that interact with myosin for contraction.

Thick filaments in muscle fibers that pull on actin during contraction.

Structures in muscle fibers that anchor actin filaments and define sarcomere length.

Involves actin and myosin filaments sliding past each other to shorten the muscle.

When action potentials occur closely, muscle twitches combine, increasing tension.

Ca2+ pumps can't remove calcium ions fast enough when action potentials are frequent.

A sustained contraction state due to rapid stimulation, preventing muscle relaxation.

Faster calcium release leads to stronger muscle contractions due to delayed pump action.

Uses creatine phosphate to swiftly generate ATP for short energy bursts lasting seconds.

Muscle fibers have one neuromuscular junction and are designed for contraction activation.

The action potential spreads through the muscle fiber's membrane to initiate contraction.

Extensions of the plasma membrane that carry action potentials into the muscle cell.

A membrane system that stores calcium ions for muscle contractions.

When action potential reaches T-tubules, Ca2+ channels in the SR open, releasing calcium into the cytoplasm.

Calcium binds to troponin, leading to muscle contraction by exposing myosin binding sites.

The ATP-driven Ca2+ pump moves calcium back into the SR to end muscle contraction.

When calcium levels decrease, tropomyosin blocks myosin binding sites, leading to muscle relaxation.

A motor unit consists of a single motor neuron and all the muscle fibers it controls.

Each muscle fiber is controlled by only one motor neuron, but one motor neuron may control many fibers.

Recruitment is the process of activating more motor neurons to meet task demands.

Muscles for strenuous tasks, like legs and back, have large motor units with many fibers.

Fine motor skills, as in fingers, require many small motor units with fewer fibers.

A twitch is a brief contraction from a single action potential in a motor neuron.

Increased contraction strength happens with more frequent action potentials sent to a muscle fiber.

Calcium ions help bind troponin, allowing actin and myosin to interact and generate tension.

Metabolizes carbohydrates to produce pyruvate and lactic acid.

Metabolizes carbohydrates and fatty acids to produce water and carbon dioxide using oxygen.

Energy production without oxygen, such as glycolysis.

Energy production that requires oxygen, like oxidative phosphorylation.

Powered by ATP generated from glycolysis and aerobic respiration.

Can convert some fast twitch muscle fibers into slow twitch fibers.

Supports, protects, and enables movement through muscle attachments.

Striated muscle found only in the heart, can generate action potentials independently.

Structures connecting cardiac muscle cells, allowing synchronized contractions.

Hollow organ muscle, slow contractions, lacks striations, can self-initiate movements.