Unit 3 Study Guide: Muscles and Muscle Tissue

Connective tissue sheath surrounding each muscle fiber

Endomysium.

Three types of muscle

Skeletal, cardiac, and smooth muscle.

Location of skeletal muscle

Attached to bones.

Location of cardiac muscle

Found in the heart.

Location of smooth muscle

Found in the walls of hollow organs.

Striated muscle

Skeletal and cardiac muscles are striated.

Branched muscle

Cardiac muscle is branched.

Voluntary muscle

Skeletal muscle is voluntary.

Muscle contraction without stimulation

Cardiac muscle can contract without stimulation from the nervous system.

Functions of muscle tissue

Movement, posture maintenance, joint stabilization, and heat generation.

Gross structure of a skeletal muscle

Composed of muscle fibers, fascicles, and connective tissue sheaths.

Connective tissue sheath surrounding each muscle fascicle

Perimysium.

Connective tissue sheath surrounding each muscle

Epimysium.

Plasma membrane of a muscle fiber

Sarcolemma.

Bundles of myofilaments inside muscle fibers

Myofibrils.

Sarcomere

The functional unit of a muscle fiber where thick and thin filaments overlap.

Thick filaments protein

Myosin.

Thin filaments protein

Actin.

Sarcoplasmic reticulum function

Stores calcium ions and releases them during muscle contraction.

T tubules function

Transmit action potentials into the muscle fiber.

Sliding filament model

Describes how sarcomeres shorten during muscle contraction.

Distance between sarcomere's Z-discs and M-line during contraction

Decreases.

Four stages of skeletal muscle contraction

Excitation, coupling, contraction, and relaxation.

Action potential

A rapid change in membrane potential that propagates along the muscle fiber.

End plate potential

A local depolarization of the muscle fiber membrane at the neuromuscular junction.

Excitation-contraction coupling

The process linking the action potential to muscle contraction.

Cross-bridge cycle purpose

To generate force during muscle contraction.

Three phases of a muscle twitch

Latent, contraction, and relaxation.

Muscle fatigue

A decline in the ability of a muscle to generate force.

Factors influencing muscle contraction

Muscle fiber type, frequency of stimulation, and muscle length.

Types of skeletal muscle fibers

Slow oxidative, fast oxidative, and fast glycolytic fibers.

Adaptations to endurance exercise

Increased capillary density, mitochondrial density, and myoglobin content.

Adaptations to resistance exercise

Increased muscle mass, strength, and neuromuscular efficiency.