Muscle Biology Quiz - Anatomy and Functions

<p>Thick filaments only (C)</p> Signup and view all the answers

<p>Presence of thin filaments only (C)</p> Signup and view all the answers

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

<p>Propulsion of contents through hollow internal organs (B)</p> Signup and view all the answers

<p>Continuous strong contractions to pump blood (A)</p> Signup and view all the answers

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

<p>Striations and the type of contraction (A)</p> Signup and view all the answers

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

<p>Chemical energy to mechanical energy (D)</p> Signup and view all the answers

<p>Cardiac muscle (A), Smooth muscle (C)</p> Signup and view all the answers

<p>To store oxygen and give color to the muscle (D)</p> Signup and view all the answers

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

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

<p>Proteins account for 20% of muscle composition (B)</p> Signup and view all the answers

<p>To accumulate during muscle fatigue (B)</p> Signup and view all the answers

<p>1:23 (D)</p> Signup and view all the answers

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

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

<p>Myosin has 2 binding sites, one for actin and one for ATPase. (A)</p> Signup and view all the answers

<p>It consists of striated fibers with peripheral nuclei. (D)</p> Signup and view all the answers

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

<p>Tendons are cord-like structures made mostly of collagen fibers. (C)</p> Signup and view all the answers

<p>Cardiac muscle shows branching fibers. (D)</p> Signup and view all the answers

<p>They assist in the alignment of myofilaments. (D)</p> Signup and view all the answers

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

<p>It decreases in width. (C)</p> Signup and view all the answers

<p>43,000 (A)</p> Signup and view all the answers

<p>It covers the myosin binding sites on actin. (A)</p> Signup and view all the answers

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

<p>The region where thick and thin filaments overlap. (B)</p> Signup and view all the answers

<p>5-8 nm (B)</p> Signup and view all the answers

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

<p>Cardiac muscle contraction (A)</p> Signup and view all the answers

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

<p>Strong, short contractions (A)</p> Signup and view all the answers

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

A type of tissue that can contract and generate force, responsible for movement in the body.

A type of muscle tissue that is attached to bones, responsible for voluntary movements.

A type of muscle tissue found in the heart, responsible for continuous, involuntary pumping of blood.

A type of muscle tissue found in the walls of internal organs, responsible for involuntary movements like digestion.

The outer membrane of a muscle cell, responsible for transmitting electrical signals.

The basic unit of a skeletal muscle, consisting of a single muscle cell containing multiple nuclei.

Striations are the alternating light and dark bands visible in skeletal and cardiac muscle, which are responsible for their striped appearance.

The nuclei of a muscle fiber are located at the periphery of the cell, unlike other cell types.

A functional unit of muscle, composed of a motor neuron and all the muscle fibers it innervates.

The ratio of motor neurons to muscle fibers in a motor unit, determines the precision of movement.

The specialized junction between a motor neuron and a muscle fiber.

The specialized area of the muscle fiber membrane where the neurotransmitter acetylcholine is released by the motor neuron.

The cytoplasm of a muscle cell, excluding the myofibrils.

The smooth endoplasmic reticulum of a muscle cell, responsible for storing and releasing calcium ions for muscle contraction.

The contractile unit of a muscle fiber, composed of repeating units of actin and myosin filaments.

A bundle of muscle fibers, containing multiple muscle cells, that works together to generate force. Think of it as a group of soldiers working together.

The basic unit of a muscle, a long cylindrical cell with multiple nuclei and specialized proteins for contraction. Imagine it as a tiny engine that drives movement.

Located within a muscle fiber, these are bundles of myofilaments, the proteins responsible for muscle contraction. Think of them as the functional units within the muscle cell.

A dense protein structure that anchors thin filaments and acts as a boundary between sarcomeres. It helps to align the myofibrils and facilitates muscle contraction.

A protein that makes up the thick filaments in muscle fibers, responsible for muscle contraction by binding to actin.

A protein that forms the thin filaments in muscle fibers, providing binding sites for myosin during contraction.

The protein that links myosin to actin in muscle fibers, playing a crucial role in muscle contraction.

The region of the sarcomere that contains only thick filaments (myosin), appearing as a dark band under a microscope.

The region of the sarcomere that contains only thin filaments (actin), appearing as a light band under a microscope.

The region of the sarcomere that contains only thick filaments (myosin) with no overlap of thin filaments.

The protein that anchors thin filaments (actin) at the ends of sarcomeres, defining the boundaries of each sarcomere.

The specialized junctions between cardiac muscle cells, allowing for rapid and efficient transmission of electrical signals for synchronized contraction.

A specialized region of cardiac muscle that initiates electrical impulses, acting as the 'pacemaker' of the heart.

A group of specialized cardiac muscle fibers that conduct electrical impulses rapidly throughout the heart, ensuring coordinated contraction.

A node in the heart that delays the electrical signal, allowing the atria to contract before the ventricles.

Cardiac muscle cells, responsible for the heart's contraction, contain myofibrils, striations, and are connected by intercalated discs.

Thick filaments are composed of two symmetrical halves, each a mirror image of the other. The main constituent is myosin, a protein with a molecular weight of 480,000. It has two ends: a globular end with two heads, and a rod-like tail. Each myosin molecule consists of six peptide chains: two identical heavy chains and four light chains.

Myosin molecules possess two binding sites: one for actin and the other for ATP. The actin binding site facilitates interaction with thin filaments, while the ATPase site is crucial for hydrolysing ATP, providing energy for muscle contraction.

Skeletal muscle is characterized by its striated appearance. It exhibits alternating light and dark bands due to the organized arrangement of actin and myosin filaments.

Tendons are cord-like structures primarily composed of collagen fibers that attach muscles to bones. They allow for strong and durable connections across joints. Aponeuroses are sheet-like structures that also attach muscles, but indirectly to bones, cartilages, or other connective tissue coverings.

Cardiac muscle is characterized by strong, continuous contractions that are involuntary and rhythmic. Its fibers are branched, have striations, and exhibit centrally located nuclei.