Muscular System Overview

Smooth muscle = Involuntary and responsible for peristalsis Cardiac muscle = Involuntary and pumps blood Skeletal muscle = Voluntary movement and posture maintenance Myocardium = Heart wall composition

Smooth muscle = Walls of hollow organs like stomach and intestines Cardiac muscle = Found only in the heart Skeletal muscle = Attached to bones for movement Connective tissue = Forms tendons that attach muscles to bones

Acetylcholine (ACh) = Neurotransmitter at the neuromuscular junction Actin = Thin protein filament in muscle fibers Myosin = Thick protein filament that interacts with actin Neuromuscular junction = Site where neuron meets muscle cell

<p>Smooth muscle = Operates involuntarily without conscious control Skeletal muscle = Constitutes major body heat production Cardiac muscle = Unique to the heart and responsible for heartbeat Fascicles = Bundles of muscle fibers grouped together</p> Signup and view all the answers

<p>Fascia = Covers and supports individual muscles Tendons = Attach muscle to bone Connective tissue sheaths = Bundle muscle fibers into fascicles Motor neurons = Stimulate muscle contraction</p> Signup and view all the answers

<p>Actin = Slide past myosin during contraction Myosin = Forms cross-bridges with actin Acetylcholine = Triggers muscle cell membrane response Neuromuscular junction = Connection point for neuron and muscle cell</p> Signup and view all the answers

<p>Smooth muscle = Controlled involuntarily by the autonomic nervous system Skeletal muscle = Controlled voluntarily by the somatic nervous system Cardiac muscle = Involuntarily controlled and rhythmic Skeletal muscle fibers = Help maintain posture through voluntary control</p> Signup and view all the answers

<p>Peristalsis = Smooth muscle action in digestive tract Heart pumping = Cardiac muscle action to circulate blood Lifting an object = Skeletal muscle contraction involved Maintaining body posture = Skeletal muscle function under voluntary control</p> Signup and view all the answers

<p>Involuntary muscles = Include smooth and cardiac types Voluntary muscles = Comprise primarily of skeletal muscle Acetylcholine release = Essential for initiating contraction Tendons = Connect muscles to bony structures</p> Signup and view all the answers

<p>Dermatomyositis = A disease of unknown origin involving muscular inflammation as well as dermatitis and skin rashes Fibromyalgia syndrome (FMS) = A disorder associated with widespread muscular aches and stiffness and having no known cause Myasthenia gravis (MG) = A disease characterized by progressive muscular weakness; an autoimmune disease affecting the neuromuscular junction Polymyositis = A disease of unknown cause involving muscular inflammation and weakness</p> Signup and view all the answers

<p>Skeletal muscle = Voluntary muscle that moves the skeleton and maintains posture Smooth muscle = Involuntary muscle that makes up the wall of hollow organs, vessels, and ducts Cardiac muscle = Involuntary muscle that makes up the heart wall Fascia = The fibrous sheath of connective tissue that covers a muscle</p> Signup and view all the answers

<p>Creatine kinase (CK) = An enzyme found in muscle tissue; the serum CK level increases in cases of muscle damage Electromyography (EMG) = Study of the electrical activity of muscles during contraction Physical therapy (PT) = Health profession concerned with physical rehabilitation and prevention of disability Rheumatology = The study and treatment of rheumatic diseases</p> Signup and view all the answers

<p>Anti-inflammatory agent = Drug that reduces inflammation; includes steroids and nonsteroidal anti-inflammatory drugs COX-2 inhibitor = Nonsteroidal anti-inflammatory drug that does not cause stomach problems Muscle relaxant = A drug that reduces muscle tension NSAID = Drug that reduces inflammation but is not a steroid; examples include aspirin and ibuprofen</p> Signup and view all the answers

<p>Agonist = The muscle that carries out a given movement Antagonist = The muscle that opposes an agonist; it must relax when the agonist contracts Tendon = A fibrous band of connective tissue that attaches a muscle to a bone Fascicle = A small bundle, as of muscle or nerve fibers</p> Signup and view all the answers

<p>Ataxia = Lack of muscle coordination Tetany = A condition marked by spasms caused by a metabolic imbalance Fasciculation = Involuntary small contractions or twitching of muscle fiber groups Tetanus = An acute infectious disease marked by painful spasms of voluntary muscles</p> Signup and view all the answers

<p>Actin = One of the two contractile proteins in muscle cells Myosin = One of the two contractile proteins in muscle cells Calcium = Needed for muscle contraction and signaling ATP = The cell’s energy compound necessary for muscle function</p> Signup and view all the answers

<p>Fibrositis = Inflammation of fibrous connective tissue, especially the muscle fasciae Rhabdomyolysis = An acute disease involving diffuse destruction of skeletal muscle cells Rhabdomyoma = A benign tumor of skeletal muscle Tendinitis = Inflammation of a tendon, usually caused by injury</p> Signup and view all the answers

<p>Neuromuscular junction (NMJ) = The point of contact between a motor neuron and a muscle cell Acetylcholine (ACh) = A neurotransmitter that stimulates contraction of skeletal muscles Fascia = Connective tissue covering muscles that supports and protects Fascicle = Bundles of muscle fibers working together within a muscle</p> Signup and view all the answers

<p>Isometric contraction = Muscle tension increases but there's no movement Isotonic contraction = Muscle changes length while maintaining tension Eccentric contraction = Muscle lengthens while producing tension Concentric contraction = Muscle shortens while producing tension</p> Signup and view all the answers