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exam 2

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Terms in this set (30)

  • Red bone marrow function

    Red marrow produces blood cells: red blood cells, white blood cells, and platelets.

  • Yellow bone marrow composition and role

    Yellow marrow consists mainly of adipose tissue and serves as an energy reserve.

  • Osteon components

    An osteon includes the central canal (blood vessels and nerves), lamellae (concentric bone matrix rings), lacunae (spaces housing osteocytes), and canaliculi (channels for nutrient/waste exchange).

  • Appositional bone growth process

    Osteogenic cells become osteoblasts adding bone matrix outside; osteoclasts remove bone inside, enlarging medullary cavity.

  • Functions of articular cartilage in synovial joints

    Reduces friction and absorbs compression; avascular and nourished by synovial fluid.

  • Ligament vs tendon vs meniscus

    Ligament: bone to bone; Tendon: muscle to bone; Meniscus: fibrocartilage pad improving joint fit and shock absorption.

  • Six types of synovial joints and example

    Hinge (elbow), Saddle (thumb carpometacarpal), Ball-and-socket (shoulder), Plane (intercarpal), Pivot (proximal radioulnar), Condylar/ellipsoid (wrist).

  • Difference between dorsiflexion and plantar flexion

    Dorsiflexion: toes move toward shin; Plantar flexion: toes point downward.

  • Three C's of knee injury triad

    Medial collateral ligament, medial meniscus, and anterior cruciate ligament.

  • Osteoarthritis effects on joints

    Articular cartilage thins and roughens, increasing friction, causing pain, stiffness, and reduced mobility.

  • Five functions of skeletal muscle

    Movement, posture, joint stabilization, support of soft tissues, and heat production.

  • Organization of skeletal muscle from largest to smallest

    Whole muscle → fascicle → muscle fiber → myofibril → myofilaments.

  • Thin filament proteins in sarcomere

    Actin, troponin (binds calcium), and tropomyosin (blocks myosin-binding sites at rest).

  • Role of T tubules and sarcoplasmic reticulum in muscle contraction

    T tubules carry action potentials into muscle fiber; sarcoplasmic reticulum stores and releases calcium.

  • Sequence at neuromuscular junction (NMJ)

    Action potential → calcium entry → ACh release → ACh binds receptors → muscle action potential → SR releases calcium.

  • How muscle contraction signal ends at NMJ

    Acetylcholinesterase breaks down ACh in synaptic cleft, stopping stimulation.

  • Cross-bridge cycle steps involving ATP

    1. Myosin binds actin; 2. Power stroke; 3. ATP binds myosin causing detachment; 4. ATP hydrolysis re-energizes myosin.

  • Cause of rigor mortis

    ATP depletion prevents myosin detachment from actin despite calcium presence, causing muscle stiffness.

  • Sodium-potassium pump function in muscle cells

    Moves 3 Na⁺ out and 2 K⁺ in; maintains resting membrane potential; Na⁺ influx causes depolarization, K⁺ efflux causes repolarization.

  • Definitions of twitch, treppe, summation, and tetanus

    Twitch: single contraction; Treppe: increasing strength in relaxed twitches; Summation: stimuli before relaxation; Tetanus: sustained contraction.

  • Motor unit definition and role

    One motor neuron and all muscle fibers it controls; more units recruited for stronger contractions.

  • Types of muscle contraction

    Concentric: muscle shortens; Eccentric: muscle lengthens under load; Isometric: tension without length change.

  • Energy systems for muscle ATP regeneration

    Phosphocreatine (fastest, ~15s), anaerobic glycolysis (fast, low yield), aerobic metabolism (slow, high yield).

  • Muscle fiber types and characteristics

    Type I: slow oxidative, fatigue resistant; Type IIa: fast oxidative-glycolytic; Type IIb: fast glycolytic, fatigues quickly.

  • Muscle atrophy vs hypertrophy

    Atrophy: muscle fiber size decreases due to disuse; Hypertrophy: muscle fiber size increases with training.

  • Difference between axial and appendicular muscles

    Axial muscles stabilize head, neck, trunk; appendicular muscles move and stabilize limbs and girdles.

  • Four fascicle arrangements and their functional advantage

    Parallel: range of motion; Convergent: versatile pull; Pennate: force; Circular: constricts openings.

  • Lever components and classes

    Lever: bone; Fulcrum: joint; Effort: muscle force; Load: resistance. Classes: 1st (fulcrum between effort/load), 2nd (load between fulcrum/effort), 3rd (effort between fulcrum/load).

  • Origin vs insertion of a muscle

    Origin: fixed, usually proximal attachment; Insertion: movable attachment.

  • Muscle roles: agonist, antagonist, synergist, fixator

    Agonist: prime mover; Antagonist: opposes action; Synergist: assists agonist; Fixator: stabilizes joint or origin.