G book Ch. 6 Skeletal Muscle Contraction Basics

<p>The actin filaments completely overlap the myosin filaments. (C)</p> Signup and view all the answers

<p>Tendon fibers (A)</p> Signup and view all the answers

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

<p>3000 (B)</p> Signup and view all the answers

<p>3 million (C)</p> Signup and view all the answers

<p>To store calcium ions (C)</p> Signup and view all the answers

<p>Through a series of intermediary proteins that relay the signal (B)</p> Signup and view all the answers

<p>They slide past each other (C)</p> Signup and view all the answers

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

<p>They form a connection between the actin and myosin filaments (B)</p> Signup and view all the answers

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

<p>They directly bind to the actin filaments, exposing binding sites for myosin (D)</p> Signup and view all the answers

<p>To mark the boundaries between sarcomeres (A)</p> Signup and view all the answers

<p>To provide structural support and regulate sarcomere length (C)</p> Signup and view all the answers

<p>It binds to receptors on the muscle fiber membrane, leading to depolarization (A)</p> Signup and view all the answers

<p>They initiate the action potential that travels along the muscle fiber membrane (A)</p> Signup and view all the answers

<p>They produce ATP, providing energy for muscle contraction (D)</p> Signup and view all the answers

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

<p>The end attached to the Z disk (C)</p> Signup and view all the answers

<p>Depolarization of the muscle fiber membrane. (A)</p> Signup and view all the answers

<p>They supply energy to the contracting myofibrils. (B)</p> Signup and view all the answers

<p>3-4 kg/cm2 (D)</p> Signup and view all the answers

<p>800 pounds (A)</p> Signup and view all the answers

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

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

<p>Increased calcium ion release (A)</p> Signup and view all the answers

<p>Smallest motor units (A)</p> Signup and view all the answers

<p>50 times stronger (D)</p> Signup and view all the answers

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

<p>High-strength movements over short distances (C)</p> Signup and view all the answers

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

<p>They increase significantly (C)</p> Signup and view all the answers

<p>It increases the rate of synthesis of muscle contractile proteins (A)</p> Signup and view all the answers

<p>Replacement of muscle fibers with fibrous tissue (B)</p> Signup and view all the answers

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

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

<p>Nervous system function (C)</p> Signup and view all the answers

<p>They can disappear from the ends of the muscle fibers. (D)</p> Signup and view all the answers

<p>Depletion of ATP. (D)</p> Signup and view all the answers

<p>To form a link between intracellular contractile proteins and extracellular connective tissue. (A)</p> Signup and view all the answers

<p>Formation of new sarcomeres. (C)</p> Signup and view all the answers

<p>Linear splitting of existing muscle fibers. (D)</p> Signup and view all the answers

<p>Duchenne muscular dystrophy (C)</p> Signup and view all the answers

<p>Loss of neural stimulation. (C)</p> Signup and view all the answers

<p>X-linked recessive (C)</p> Signup and view all the answers

A large protein that connects myosin thick filaments to Z disks and acts like a spring.

The basic unit of a muscle's cross-striated myofibril, responsible for muscle contraction.

The structure at the two ends of a sarcomere where titin and actin filaments attach.

A nerve that transmits signals from the brain to muscles to initiate movement.

A neurotransmitter that triggers muscle contraction by acting on muscle fiber membranes.

The intracellular fluid found between myofibrils in muscle fibers, rich in ions and enzymes.

Channels in the muscle membrane that open in response to depolarization, allowing sodium ions to enter.

An electrical impulse that travels along the nerve or muscle membrane to induce contraction.

A molecule that provides energy for cellular processes, formed in mitochondria.

A specialized endoplasmic reticulum in skeletal muscle that stores calcium ions.

Minerals released from the sarcoplasmic reticulum that initiate muscle contractions.

Thin protein strands that slide during muscle contraction, interacting with myosin.

Thick protein strands that pull on actin filaments to cause muscle contraction.

Connections formed between actin and myosin filaments during muscle contraction.

Boundaries of the muscle fiber that move closer together during contraction.

A thin membrane enclosing a skeletal muscle fiber.

The light and dark bands found in skeletal and cardiac muscle.

Threadlike structures composed of actin and myosin filaments.

A large protein that keeps actin and myosin filaments in place.

The process where actin and myosin filaments slide past each other.

New sarcomeres can be added rapidly in developing muscle.

Muscles contract and stiffen without action potentials due to ATP loss.

Muscles remain in rigor for 15 to 25 hours after ATP depletion.

Muscles are continually remodeled for optimal length.

Increase in actual muscle fiber numbers under extreme force.

An X-linked disorder causing muscle weakness and degeneration.

Protein that links actin to muscle cell membrane proteins.

Denervation leads to rapid muscle atrophy.

Enlargement of individual muscle fibers due to strength training.

The study of movement and the mechanics of body systems.

The size of a muscle fiber that contributes to strength.

Strong muscle contractions that trigger muscle growth.

Proteins like actin and myosin that enable muscle contraction.

Loss of muscle mass due to nerve damage.

Shortening of muscles due to fibrosis after atrophy.

Normal muscle length averages between 3 and 4 kg/cm² or 50 pounds/inch².

A quadriceps muscle can have up to 16 square inches of muscle belly.

Increased contraction by activating more motor units simultaneously.

Increased contraction intensity by raising the frequency of motor unit activations.

The result of high-frequency stimulation causing sustained muscle contraction.

The phenomenon where muscle strength increases with each twitch after rest.

The strength of a muscle's contraction may be half its maximum after rest.

Larger motor units have more contractile force than smaller ones.