BSC2085C Exam Study Guide - Skeletal and Muscular Systems

Vocabulary flashcards based on key concepts from the BSC2085C study guide covering both the skeletal and muscular systems.

Functions of the skeletal system

Support, protection, movement, mineral storage, and blood cell production.

Red vs. Yellow marrow

Red marrow produces blood cells, while yellow marrow stores fat.

Types of tissues in the skeletal system

Bone tissue, cartilage, and connective tissues.

Structure & components of a long bone

Includes diaphysis, epiphysis, metaphysis, and bone marrow.

Spongy vs. compact bone

Spongy bone is lighter and porous; compact bone is dense and forms the outer layer.

Osteons

Structural units of compact bone, consisting of concentric layers of bone matrix.

Canaliculi

Small channels that connect osteocytes to each other and to the central canal.

Trabeculae

The supporting bundles of bony fibers in spongy bone.

Matrix of bone

Extracellular material made of organic and inorganic components providing structure.

Osteoblast function

Bone-forming cells responsible for secreting bone matrix.

Osteoclast function

Bone-resorbing cells that break down bone tissue.

Intramembranous bone formation

Process by which bone develops from a fibrous membrane.

Endochondral bone formation

Process of bone development from a cartilage model.

Epiphyseal plate

Growth plate responsible for the lengthening of bones during growth.

Bone maintenance hormones

Thyroid hormones regulate metabolism; parathyroid hormones regulate calcium levels.

Steps of bone repair

Inflammation, callus formation, ossification, and remodeling.

Fibrous joints

Joints connected by dense connective tissue; immovable.

Cartilaginous joints

Joints connected by cartilage; slightly movable.

Synovial joints

Freely movable joints with a synovial cavity and fluid.

Structure of a synovial joint

Includes articular cartilage, joint capsule, synovial membrane, and synovial fluid.

Muscular system functions

Movement, stability, heat production, and posture.

Byproducts of muscle contraction

Lactic acid and heat.

Types of muscle tissues

Skeletal, cardiac, and smooth muscles.

Anatomy of a muscle cell

Includes sarcolemma, sarcoplasm, myofibrils, and nuclei.

Anatomy of a skeletal muscle

Composed of bundles of muscle fibers surrounded by connective tissue.

Smooth muscle structure

Non-striated, involuntary muscle with spindle-shaped cells.

Peristalsis

Wave-like muscle contractions that move food through the digestive tract.

Tendon

A fibrous connective tissue that connects muscle to bone.

Aponeurosis

A flat sheet of connective tissue that connects muscle to muscle or bone.

Connective tissue layers of skeletal muscles

Epimysium surrounds the whole muscle; perimysium surrounds fascicles; endomysium surrounds individual fibers.

Muscle vs. fascicle vs. muscle fiber

Muscle is the organ, fascicle is a bundle of fibers, and muscle fiber is a single muscle cell.

Myofibril vs. sarcomere

Myofibrils are composed of multiple sarcomeres, the basic unit of contraction.

Thin (actin) vs. thick filament (myosin)

Actin is the thin filament, while myosin is the thick filament in muscle contraction.

I band vs. A band

I band is light and only contains actin; A band is dark and contains both actin and myosin.

M-line vs. Z-line

M-line is the middle of the sarcomere; Z-line marks the boundaries of each sarcomere.

Roles of tropomyosin and troponin

Tropomyosin blocks binding sites on actin; troponin binds calcium and moves tropomyosin.

Steps of muscle excitation

Action potential triggers release of acetylcholine, leading to depolarization of the sarcolemma.

Role of acetylcholine

Neurotransmitter that triggers muscle contraction.

Role of t-tubule

Transmit action potentials into the muscle cell interior.

Role of sarcoplasmic reticulum

Stores and releases calcium ions for muscle contraction.

Troponin vs. tropomyosin

Troponin binds calcium; tropomyosin covers binding sites on actin.

Steps of muscle contraction/sliding filament

Calcium ions bind to troponin, tropomyosin moves, and myosin heads pull on actin filaments.

Role of creatine phosphate

Acts as an energy reservoir for rapid ATP regeneration.

Roles of hemoglobin and myoglobin

Hemoglobin transports oxygen in blood; myoglobin stores oxygen in muscle.

Glycolysis vs. aerobic respiration

Glycolysis occurs in the cytoplasm without oxygen; aerobic respiration occurs in mitochondria with oxygen.

Fermentation and lactic acid buildup

Occurs during anaerobic respiration when oxygen is scarce, leading to fatigue.

Factors affecting oxygen availability

Altitude, physical fitness, and lung capacity affect oxygen availability in muscles.

Factors affecting oxygen demand

Intensity and duration of exercise increase oxygen demand.

Fatigue

Inability to maintain expected power output due to physiological or psychological factors.

Motor unit

A motor neuron and all the muscle fibers it innervates.

Tonic vs. twitch fibers

Tonic fibers are slow and resistant to fatigue; twitch fibers contract quickly and fatigue easier.

Traits of slow twitch fibers-type I

High endurance, more myoglobin, and oxidative metabolism.

Traits of fast twitch oxidative fibers-type IIa

Intermediate fibers; moderate endurance and can use both aerobic/anaerobic metabolism.

Traits of fast twitch glycolytic fiber-type IIx

Low endurance, high-speed contraction, primarily anaerobic.

Distribution of each fiber type

Varies among individuals and muscle groups based on training and genetics.

Switch from type IIa to IIx

Occurs with increased anaerobic training.

Effect of aerobic training on muscle fibers

Increases capillarity and oxidizing enzymes in muscle fibers.

Hypertrophy

Increase in muscle size due to resistance training.

Atrophy

Decrease in muscle size due to disuse or aging.