Muscle Tissues

Flashcards focusing on key vocabulary terms related to muscle tissues.

Myoblast

A mesenchymal cell that gives rise to a myocyte.

Myocyte

A cell that constitutes muscle tissue and does not divide.

Sarcoplasm

The cytoplasm of a muscle fiber.

Sarcolemma

The plasma membrane of a muscle cell.

Sarcoplasmic reticulum

A specialized form of smooth endoplasmic reticulum involved in muscle contraction.

Myoglobulin

An oxygen-binding pigment found in muscle cells.

T tubules

Invaginations of the sarcolemma that facilitate the propagation of electrical signals in muscle cells.

Actin

A contractile protein forming thin filaments in muscle fibers.

Myosin

A contractile protein forming thick filaments in muscle fibers.

Troponin

A regulatory protein that binds calcium ions and is involved in muscle contraction.

Calmodulin

A calcium-binding protein that plays a critical role in muscle contraction in smooth muscle.

Muscle fatigue

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

Aerobic respiration

The process by which cells use oxygen to produce energy in the form of ATP.

Anaerobic glycolysis

A metabolic process that converts glucose to lactic acid when oxygen is insufficient.

Type I Fibers

Slow-twitch muscle fibers that are fatigue-resistant and utilize aerobic metabolism.

Type II Fibers

Fast-twitch muscle fibers that generate more power but fatigue quickly.

Motor unit

A motor neuron and all the muscle fibers it innervates.

Neuromuscular junction

The synapse between a motor neuron and a muscle fiber.

Rigor mortis

Muscle stiffness that occurs after death due to lack of ATP, causing myosin to remain bound to actin.

Desmin

A structural protein that helps align myofibrils in muscle cells.

What is the role of calcium ions in muscle contraction and which protein do they bind to?

A) They bind to myoglobin
B) They bind to desmin
C) They bind to troponin
D) They bind to myosin

Distinguish between aerobic respiration and anaerobic glycolysis in the context of muscle metabolism.

A) Aerobic respiration is faster and produces lactic acid; anaerobic glycolysis is slower and requires oxygen.
B) Aerobic respiration occurs in Type II fibers; anaerobic glycolysis occurs in Type I fibers.
C) Aerobic respiration requires oxygen and produces more ATP; anaerobic glycolysis does not require oxygen and produces lactic acid.
D) There is no difference; both processes are equivalent.

Explain the significance of motor units in muscle contraction and how they relate to muscle control.

A) Motor units allow for all or nothing muscle contraction.
B) Motor units consist of neurons only, with no relation to muscle fibers.
C) Motor units help control the force of muscle contraction by recruiting different fibers.
D) Motor units are only important in Type I fibers.