Muscle Terminology PDF

Dr. Aisha Alhaddad (2024) - The main characteristic of muscle tissue is its ability to contract. When stimulated, muscles shorten to produce movement of the skeleton, vessel walls, or internal organs. - Muscles may also remain partially contracted to maintain posturer. Types of Muscles There are...

Dr. Aisha Alhaddad (2024) - The main characteristic of muscle tissue is its ability to contract. When stimulated, muscles shorten to produce movement of the skeleton, vessel walls, or internal organs. - Muscles may also remain partially contracted to maintain posturer. Types of Muscles There are three types of muscle tissue in the body : 1- Smooth (visceral) muscle makes up the walls of the hollow organs, such as the stomach, intestines, and uterus, and the walls of ducts, such as the blood vessels and bronchioles. Smooth muscle operates involuntarily and is responsible for peristalsis, the wave-like movements that propel materials through the systems. 2- Cardiac muscle makes up the myocardium of the heart wall. It functions involuntarily and is responsible for the heart’s pumping action. 3- Skeletal muscle is attached to bones and is responsible for voluntary movement. It also maintains posture and generates a large proportion of body heat. All of these voluntary muscles together make up the muscular system. Skeletal Muscle Muscles are composed of individual cells, often referred to as fibers because they are so long. These cells are held together in fascicles (bundles) by connective tissue. Covering each muscle is a sheath of connective tissue or fascia. These supporting tissues merge to form the tendons that attach the muscle to bones. Skeletal muscles are stimulated to contract by motor neurons of the nervous system. At the neuromuscular junction (NMJ), the synapse (junction) where a branch of a neuron meets a muscle cell, the neurotransmit- ter acetylcholine (ACh) is released from small vesicles (sacs) in an axon branch. ACh interacts with the muscle cell mem brane to prompt cellular contraction. Two special protein filaments in muscle cells, actin and myosin, interact to produce the contraction. ATP (the cell’s energy compound) and calcium are needed for this response  Normal Structure Function Acetylcholine (ACh) A neurotransmitter that stimulates contraction of skeletal muscles Agonist A muscle that carries out a given movement Antagonist The muscle that opposes an agonist; it must relax when the agonist contracts Fascia The fibrous sheath of connective tissue that covers a muscle Fascicle A small bundle, as of muscle or nerve fibers Neuromuscular junction (NMJ) The point of contact, or synapse, between a branch of a motor neuron and a muscle cell Normal Structure Function Actin One of the two contractile proteins in muscle cells Myosin One of the two contractile proteins in muscle cells 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 Tendon A fibrous band of connective tissue that attaches a muscle to a bone  Disorder Definition 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 Muscular dystrophy A group of hereditary muscular disorders marked by progressive weakness and muscular atrophy 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 Tendinitis Inflammation of a tendon, usually caused by injury  Disorder Definition Ataxia Lack of muscle coordination Fasciculation Involuntary small contractions or twitching of muscle fiber groups Fibrositis Inflammation of fibrous connective tissue, especially the muscle fasciae; marked by pain and stiffness Rhabdomyolysis An acute disease involving diffuse destruction of skeletal muscle cells Rhabdomyoma A benign tumor of skeletal muscle Tetanus An acute infectious disease caused by the anaerobic bacillus Clostridium tetani; marked by persistent painful spasms of voluntary muscles Tetany A condition marked by spasms, cramps, and muscle twitching caused by a metabolic imbalance such as low blood calcium resulting from underactivity of the parathyroid glands  Procedure Definition Creatine kinase (CK) An enzyme found in muscle tissue; the serum CK level increases in cases of muscle damage; Electromyography Study of the electrical activity of muscles during contraction (EMG) Physical therapy (PT) Health profession concerned with physical rehabilitation and prevention of disability exercise, massage, and other therapeutic methods are used to restore proper movement Rheumatology The study and treatment of rheumatic diseases  Drugs Definition Anti-inflammatory agent Drug that reduces inflammation; includes steroids, such as cortisol, and nonsteroidal anti-inflammatory drugs COX-2 inhibitor Nonsteroidal anti-inflammatory drug that does not cause the stomach problems associated with other NSAIDs; inhibits the cyclooxygenase (COX)- 2 enzyme without affecting the COX-1 enzyme Muscle relaxant A drug that reduces muscle tension; Nonsteroidal, anti- Drug that reduces inflammation but is not a steroid; examples include inflammatory drug aspirin, ibuprofen and other inhibitors of prostaglandins, naturally (NSAID) produced substances that promote inflammation