Muscular System and Muscle Types

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Questions and Answers

What type of muscle is responsible for body movements, stabilizing joints, and generating heat?

Cardiac muscle

Smooth muscle

Visceral muscle

Skeletal muscle (correct)

What prefix refers to muscle?

mys

myo (correct)

sarco

cyto

Which type of muscle tissue attaches to the bones of the skeleton via tendons?

Cardiac muscle

Smooth muscle

Skeletal muscle (correct)

Visceral muscle

What is the structure of skeletal muscle cells?

Long cylindrical, multinucleated, striated Signup and view all the answers

How do skeletal muscles generate the force required for movement?

By contracting myofilaments Signup and view all the answers

What is the function of skeletal muscles in addition to whole body movements?

To move substances inside the body Signup and view all the answers

What is the main function of the skeletal muscle?

Movement and posture of the body Signup and view all the answers

Which of the following is NOT a characteristic of skeletal muscle?

Involuntary contraction Signup and view all the answers

What is the name of the basic functional unit of the skeletal muscle?

Muscle fiber Signup and view all the answers

Which of the following is NOT a property of skeletal muscle fibers?

Ability to perform phagocytosis Signup and view all the answers

What is the name of the structure that transmits the nerve impulse from the motor neuron to the skeletal muscle fiber?

Neuromuscular junction Signup and view all the answers

Which of the following is the main energy source for skeletal muscle contraction?

Glycogen Signup and view all the answers

What is the primary function of the cardiac muscle?

To form the wall of the heart Signup and view all the answers

Which of the following is a characteristic of skeletal muscle cells?

Multinucleate Signup and view all the answers

What is the role of the sarcoplasmic reticulum in skeletal muscle contraction?

It releases calcium ions to initiate muscle contraction. Signup and view all the answers

What is the contractile unit of skeletal muscle?

The sarcomere Signup and view all the answers

What is the role of the Z-disc in a skeletal muscle sarcomere?

It marks the boundary between adjacent sarcomeres. Signup and view all the answers

What is the purpose of the H-zone in a skeletal muscle sarcomere?

It is the area that lacks actin filaments when the muscle is at rest. Signup and view all the answers

What is the role of the M-line in a skeletal muscle sarcomere?

It connects the thick myosin filaments. Signup and view all the answers

What is the purpose of the neuromuscular junction in skeletal muscle contraction?

It releases the neurotransmitter acetylcholine. Signup and view all the answers

What is the purpose of the sodium-potassium pump in skeletal muscle relaxation?

It pumps sodium and potassium back to their original positions. Signup and view all the answers

What is the difference between unfused tetanus and fused tetanus in skeletal muscle contraction?

Unfused tetanus results in a more forceful and prolonged contraction, while fused tetanus involves some relaxation between contractions. Signup and view all the answers

Study Notes

Muscle Types and Functions

Skeletal muscle is responsible for body movements, stabilizing joints, and generating heat.
Cardiac muscle maintains heart function.
Smooth muscle controls involuntary movements within organs.

Muscle Terminology

The prefix "myo-" refers to muscle.

Skeletal Muscle Tissue

Skeletal muscle tissue attaches to the bones of the skeleton via tendons.
Skeletal muscle cells are long, cylindrical, multinucleated, and striated in appearance.

Muscle Force Generation

Skeletal muscles generate force through contraction, using ATP as the main energy source for skeletal muscle contraction.
Muscle contractions are triggered by nerve signals, transmitted from motor neurons to skeletal muscle fibers at the neuromuscular junction.

Functions of Skeletal Muscles

In addition to enabling whole-body movements, skeletal muscles also help maintain posture and generate heat during activity.
The primary function of skeletal muscle is to facilitate voluntary movements.

Characteristics of Skeletal Muscle

While it is characterized by striations, voluntary control, and fatigue resistance, certain attributes like involuntary contraction are NOT associated with skeletal muscle.
The basic functional unit of skeletal muscle is called the sarcomere.

Muscle Fiber Properties

Skeletal muscle fibers exhibit properties such as excitability, contractility, extensibility, and elasticity.
They do not possess the capability for spontaneous contraction.

Neuromuscular Transmission

The structure that transmits nerve impulses from the motor neuron to the skeletal muscle fiber is the neuromuscular junction.
The sarcoplasmic reticulum plays a crucial role in muscle contraction by storing and releasing calcium ions.

Sarcomere Components

The contractile unit of skeletal muscle is the sarcomere.
The Z-disc serves as the boundary of each sarcomere, anchoring thin filaments.
The H-zone is the region of a sarcomere that contains only thick filaments (myosin).
The M-line, located in the center of the H-zone, provides structural support by anchoring thick filaments.

Muscle Contraction Mechanism

Sodium-potassium pumps aid in skeletal muscle relaxation by restoring resting membrane potential.
There are differences between unfused tetanus, which allows for partial relaxation between stimuli, and fused tetanus, where the muscle does not relax and contractions summate continuously.

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Description

Learn about the three basic muscle types found in the body: skeletal, cardiac, and smooth muscles. Understand how muscles generate force through contraction and the common terminology associated with muscles. Explore the importance of muscles in body movements and internal substance transportation.