Muscular System Overview Quiz

Muscular System Overview

• The muscular system's core function is contraction, enabling movement of skeletal structures, internal organs, blood vessels.
• Muscles maintain posture through partial contraction.

Types of Muscles

• Smooth muscle: Found in hollow organs (stomach, intestines, blood vessels), responsible for involuntary peristalsis (wave-like movements).
• Cardiac muscle: Forms the heart wall (myocardium), responsible for involuntary pumping action.
• Skeletal muscle: Attached to bones, responsible for voluntary movement, posture maintenance, and heat generation. Skeletal muscles together create the muscular system.

Skeletal Muscle Structure

• Skeletal muscle is comprised of individual cells called fibers, bundled together in fascicles.
• These fascicles are surrounded by connective tissue (epimysium, perimysium), which merge to form tendons that attach the muscles to bones.
• Muscle fibers contain myosin and actin filaments, crucial for contraction.
• Neurotransmitters, like acetylcholine (ACh), initiate muscle contraction at the neuromuscular junction (NMJ).

Skeletal Muscle Contraction

• Motor neurons stimulate skeletal muscles at the neuromuscular junction (NMJ).
• ACh is released, binding to muscle cell membranes to trigger contraction.
• Myosin and actin filaments interact to cause contraction. ATP (adenosine triphosphate) and calcium are necessary for this process.

Muscular System Terminology

• Agonist: The muscle performing a particular movement
• Antagonist: The muscle opposing the movement of the agonist.
• Fascia: Connective tissue sheath covering muscles.
• Fascicle: A bundle of muscle fibers.
• Neuromuscular Junction (NMJ): Where motor neuron branches connect with a muscle cell.
• Acetylcholine (ACh): A neurotransmitter critical to initiating muscle contraction.
• Actin & Myosin: Protein filaments essential for muscle contraction.

Muscular System Roots

• My/o: Muscle
• Muscul/o: Muscle
• In/o: Fibre
• Fasci/o: Fascia
• Ten/o, Tendin/o: Tendon
• Ton/o: Tone
• Erg/o: Work
• Kin/o-, Kine, Kinesi/o, Kinet/o: Movement

Disorders of the Muscular System

• Dermatomyositis: Inflammation of muscles and skin.
• Fibromyalgia Syndrome (FMS): Widespread muscle pain and stiffness without known cause.
• Muscular Dystrophy: Group of hereditary muscular diseases resulting in progressive weakness and atrophy.
• Myasthenia Gravis (MG): Autoimmune disease causing weakness & fatigue in muscles.
• Polymyositis: Inflammation of multiple muscles.
• Tendinitis: Inflammation of tendons, usually due to injury.
• Ataxia: Lack of muscle coordination
• Fasciculation: Involuntary muscle twitching.
• Fibrositis: Inflammation of fibrous connective tissue, affecting muscles.
• Rhabdomyolysis: Acute muscle destruction.
• Rhabdomyoma: Benign skeletal muscle tumor.
• Tetanus: Severe muscle spasms caused by bacterial infection.
• Tetany: Muscle spasms or cramps caused by metabolic imbalance (low calcium).

Diagnosis and Management

• Creatine Kinase (CK): Enzyme elevated in muscle damage.
• Electromyography (EMG): Measures electrical activity in muscles.
• Physical Therapy (PT): Improves movement, mobility and rehabilitation.
• Rheumatology: Study and treatment of rheumatic diseases.

Drugs for Muscular System

• Anti-inflammatory agents: Reduce inflammation (steroids, NSAIDs).
• COX-2 inhibitors: NSAIDs that target a specific enzyme.
• Muscle relaxants: Reduce muscle tension.
• Nonsteroidal anti-inflammatory drugs (NSAIDs): Reduces inflammation.

Test your knowledge on the muscular system with this comprehensive quiz. Explore the functions, types, and structures of muscles, including smooth, cardiac, and skeletal muscles. Understand how these muscles contribute to movement and posture.