muscular system

"What percentage of body weight is skeletal muscle?"

"Approximately 40%"

"What is muscle contraction?"

"The ability of a muscle fiber to generate force"

"What type of energy is converted during muscle movement?"

"Chemical energy is converted into mechanical energy"

"What are the 3 types of muscle tissue?"

"Skeletal muscle; Cardiac muscle; Smooth muscle"

"What are the main functions of muscles?"

"Movement; Posture; Heat production; Organ support"

"What are the characteristics of skeletal muscle?"

"Attached to bones; Voluntary control; Striated; Long cylindrical fibers; Multinucleated cells"

"What are the functions of skeletal muscle?"

"Movement; Facial expressions; Maintaining posture; Heat production"

"Most skeletal muscles extend from where to where?"

"From one bone across a joint to another bone"

"What attaches muscles to bones?"

"Tendons"

"What are bursae?"

"Small synovium-lined sacs containing synovial fluid"

"Origin"

"Point of attachment to the bone"

"Insertion"

"Point of attachment to the bone that moves when a muscle contracts"

"Body of a muscle"

"Main part of the muscle"

"What are the characteristics of cardiac muscle?"

"Found only in the heart; Involuntary; Striated; Branched fibers; Intercalated discs"

"What are the functions of cardiac muscle?"

"Pumps blood; Maintains circulation; Continuous rhythmic contractions"

"What are the characteristics of smooth muscle?"

"Involuntary; Non-striated; Spindle-shaped cells"

"Where is smooth muscle found?"

"Blood vessels; Digestive tract; Bladder; Airways"

"What are the functions of smooth muscle?"

"Moves substances through organs; Controls blood flow"

"Levels of muscle organization"

"Muscle organ; Fascicle; Muscle fiber; Myofibril; Sarcomere"

"What is a sarcomere?"

"The basic contractile unit of muscle"

"What are the connective tissue coverings of skeletal muscle?"

"Epimysium; Perimysium; Endomysium"

"Epimysium location"

"Outermost layer surrounding the entire skeletal muscle"

"Epimysium function"

"Protects muscle; Maintains shape; Merges with tendons"

"Perimysium location"

"Surrounds fascicles"

"Perimysium function"

"Supports fascicles and carries blood vessels and nerves"

"Endomysium location"

"Surrounds individual muscle fibers"

"Endomysium function"

"Insulates muscle fibers and contains capillaries and nerve endings"

"What is a muscle fiber?"

"A muscle cell specialized for contraction"

"What do muscle fibers contain?"

"Myofibrils"

"Important parts of a muscle fiber"

"Sarcolemma; Sarcoplasm; Mitochondria; Myoglobin"

"Sarcolemma"

"The specialized plasma membrane of a muscle fiber"

"Sarcoplasm"

"The cytoplasm of a muscle cell"

"Mitochondria"

"Produce ATP through cellular respiration"

"Myoglobin"

"Oxygen-storing protein in muscle cells"

"What are the contractile proteins?"

"Actin and Myosin"

"Actin"

"Thin filament"

"Myosin"

"Thick filament"

"What are the bands and zones of a sarcomere?"

"A band; I band; H zone; Z lines"

"Sliding filament theory"

"Muscles contract when actin and myosin slide past each other"

"Z lines"

"Boundaries of a sarcomere"

"A band"

"Dark region containing the full length of thick filaments"

"I band"

"Light region containing only thin filaments"

"H zone"

"Center region containing only thick filaments"

"M line"

"Center line anchoring thick filaments"

"What shortens during muscle contraction?"

"I bands and H zones"

"What are the main functions of skeletal muscles?"

"Movement; Maintaining posture; Heat production; Stabilizing joints; Protecting organs"

"Examples of muscle movement"

"Walking; Running; Writing; Speaking"

"What are the types of muscle actions?"

"Flexion; Extension; Rotation; Abduction; Adduction"

"Posture"

"Continuous low-level muscle contractions that keep the body upright"

"Heat production"

"Muscle activity generates heat to regulate body temperature"

"What increases heat production?"

"Shivering"

"What is muscle fatigue?"

"Temporary loss of muscle performance after activity"

"Causes of muscle fatigue"

"ATP depletion; Oxygen deficiency; Lactic acid buildup; Dehydration"

"How can muscle fatigue be prevented?"

"Rest; Hydration; Proper nutrition; Exercise training"

"What is the role of the nervous system in movement?"

"Sends signals to muscles"

"What is the role of the skeletal system in movement?"

"Provides support and levers"

"What is the role of the circulatory system in movement?"

"Supplies oxygen and nutrients"

"What is the role of the respiratory system in movement?"

"Provides oxygen and removes carbon dioxide"

"What is a motor unit?"

"A motor neuron and all muscle fibers it controls"

"Importance of motor units"

"Controls muscle strength and coordinates movement"

"Small motor units"

"Provide precise movement"

"Large motor units"

"Provide powerful movement"

"Where are large motor units found?"

"Quadriceps; Hamstrings; Back muscles"

"Large motor units control what type of fibers?"

"Fast-twitch (Type II) fibers"

"How many fibers may a small motor unit control?"

"As few as 2 to 10 muscle fibers"

"What do muscles respond to?"

"Electrical impulses; Nerve stimulation; Chemical signals"

"What is the neuromuscular junction?"

"The connection between a nerve and a muscle"

"What neurotransmitter triggers muscle contraction?"

"Acetylcholine (ACh)"

"What are isotonic contractions?"

"Muscle contractions where tension remains constant while length changes"

"Concentric contraction"

"Muscle shortens while generating force"

"Example of concentric contraction"

"Lifting a weight"

"Eccentric contraction"

"Muscle lengthens while generating tension"

"Example of eccentric contraction"

"Lowering a weight slowly"

"What is an isometric contraction?"

"Muscle generates force without changing length"

"Example of an isometric contraction"

"Plank exercise"

"Positive effects of exercise on muscles"

"Increased strength; Greater endurance; Improved flexibility; Better circulation; Hypertrophy"

"Hypertrophy"

"Increase in muscle size"

"Effects of inactivity"

"Muscle atrophy; Weakness"

"Angular movements"

"Flexion; Extension; Hyperextension; Abduction; Adduction"

"Circular movements"

"Rotation; Circumduction"

"Special movements"

"Supination; Pronation; Dorsiflexion; Plantar flexion"

"Flexion"

"Decreases the angle between bones"

"Extension"

"Increases the angle between bones"

"Hyperextension"

"Extension beyond anatomical position"

"Rotation"

"Movement around an axis"

"Circumduction"

"Circular movement of a limb"

"Elevation"

"Movement upward"

"Depression"

"Movement downward"

"Opposition"

"Touching the thumb to the fingertips"

"Inversion"

"Turning the sole of the foot inward"

"Eversion"

"Turning the sole of the foot outward"

"What are the major skeletal muscle groups?"

"Head; Neck; Upper extremity; Trunk; Lower extremity"

"Facial muscles"

"Frontalis; Orbicularis oculi; Orbicularis oris; Buccinator"

"Muscles of mastication"

"Masseter; Temporalis"

"Functions of head muscles"

"Facial expressions; Chewing; Speaking"

"Major neck muscles"

"Sternocleidomastoid; Trapezius; Scalenes"

"Functions of neck muscles"

"Head movement; Neck stabilization; Posture support"

"Shoulder and arm muscles"

"Deltoid; Biceps brachii; Triceps brachii; Brachialis"

"Forearm muscles"

"Flexors; Extensors"

"Functions of upper extremity muscles"

"Lifting; Pulling; Gripping"