Class 5 - App - Muscular System Definitions Flashcards
What is Smooth Muscle?
Involuntary muscle found in walls of organs, blood vessels, and respiratory passages.
What is Cardiac Muscle?
Involuntary muscle located in the heart.
What is Skeletal Muscle?
Voluntary muscle attached to bones, responsible for body movement.
What does Excitable mean in muscle context?
Ability of muscle to respond to stimulation from the nervous system.
What does Contractile mean?
Ability of muscle to shorten forcefully.
What does Extensible mean?
Ability of muscle to be stretched or lengthened.
What does Elastic mean?
Ability of muscle to return to its original size and shape after stretching.
What is Endomysium?
Connective tissue surrounding each individual muscle fiber.
What is Perimysium?
Connective tissue surrounding a bundle of muscle fibers (fascicle).
What is Epimysium?
Connective tissue surrounding the entire muscle.
What is Fascia?
Tough, pliable sheet of connective tissue that covers, divides, and supports body structures.
What is a Tendon?
A cord-like structure that connects muscle to bone.
What is Aponeurosis?
A broad, flat sheet of connective tissue connecting muscles to bones or other tissues.
What is a Myofibril?
Cylindrical organelles inside muscle fibers made of myofilaments.
What is a Myofilament?
Protein filaments (actin and myosin) in muscle fibers responsible for contraction.
What is Actin?
Thin, light-colored myofilament involved in muscle contraction.
What is Myosin?
Thick, dark-colored myofilament that interacts with actin to cause contraction.
What is a Sarcomere?
The basic contractile unit of muscle fibers.
What is Sarcolemma?
The plasma membrane of a muscle fiber.
What is Sarcoplasm?
The cytoplasm within a muscle fiber.
What is Sarcoplasmic Reticulum?
The endoplasmic reticulum in muscle cells that stores and releases calcium.
What is the Sliding Filament Mechanism?
The process of muscle contraction where myosin pulls actin filaments together, shortening the muscle.
What is a Motor Neuron?
Nerve cells that transmit signals from the brain and spinal cord to muscles, triggering contraction.
What is a Motor Unit?
A motor neuron and all the muscle fibers it stimulates.
What is a Neuromuscular Junction?
The synapse between a motor neuron and a muscle fiber.
What is Acetylcholine?
A neurotransmitter released by motor neurons to stimulate muscle contraction.
What is a Threshold Stimulus?
The minimum level of stimulation required to cause a muscle contraction.
What is ATP (Adenosine Triphosphate)?
The energy molecule used to power muscle contractions and relaxations.
What is a Musculotendinous Junction?
The transitional zone from muscle fascia to tendon or aponeurosis.
What is a Tenoperiosteal Junction?
The transitional zone from tendon/aponeurosis to bone periosteum.
