Muscles and Muscle Tissue

Flashcards about Muscles and Muscle Tissue.

What prefixes refer to muscle?

Myo, mys, and sarco

What are the three types of muscle tissue?

Skeletal, cardiac, and smooth

What are the key words for skeletal muscle?

Skeletal, striated, and voluntary

What are the key words for cardiac muscle?

Cardiac, striated, and involuntary

What are the key words for smooth muscle?

Visceral, nonstriated and involuntary

List four characteristics of muscle tissue.

Excitability, Contractility, Extensibility, Elasticity

List four important functions of muscle.

Produce movement, Maintain posture and body position, Stabilize joints, Generate heat

What are the three connective tissue sheaths from external to internal?

Epimysium, Perimysium, Endomysium

What is the definition of insertion regarding muscle attachment?

Attachment to movable bone

What is the definition of origin regarding muscle attachment?

Attachment to immovable or less movable bone

What is the definition of Sarcolemma?

Muscle fiber plasma membrane

What is the definition of Sarcoplasm?

Muscle fiber cytoplasm

What is a Sarcomere?

Smallest contractile unit (functional unit) of muscle fiber

What two proteins compose Myofilaments?

Actin and Myosin

What protein is lacking in Duchenne Muscular Dystrophy?

Dystrophin

What is the role of Sarcoplasmic reticulum?

Regulation of intracellular Ca2+ levels; Stores and releases Ca2+

What occurs during the sliding filament model of contraction?

Thin filaments slide past thick filaments, causing actin and myosin to overlap more

What neurotransmitter is used to cross from neuron to muscle cell?

Acetylcholine (ACh)

What two classes of ion channels play a role in the change of membrane potentials?

Chemically gated ion channels and Voltage-gated ion channels

What four steps must occur for skeletal muscle to contract?

Events at neuromuscular junction, Muscle fiber excitation, Excitation-contraction coupling, Cross bridge cycling

What occurs when a nerve impulse reaches a neuromuscular junction?

Acetylcholine (ACh) is Released

What is Myasthenia Gravis?

Disease characterized by drooping upper eyelids, difficulty swallowing and talking, and generalized muscle weakness caused by shortage of Ach receptors as person’s ACh receptors are attacked by own antibodies.

What three steps occur during the generation of an action potential?

Generation of end plate potential, Depolarization, Repolarization

What occurs during Excitation-Contraction (E-C) Coupling?

Events that transmit AP along sarcolemma (excitation) are coupled to sliding of myofilaments (contraction)

What occurs during cross bridge cycling?

Myosin heads pull thin filaments toward the center of the sarcomere

What occurs during Rigor Mortis?

Muscles begin to stiffen 3–4 hours after death, peaking at 12 hours postmortem due to increased intracellular calcium levels and lack of ATP, resulting in cross bridge formation and constant muscle contraction until muscle proteins break down.