Muscular System : Part 1

Endomysium separates individual muscle fibers from each other. true false

• true

• false

What is a function of muscles?

• Pumping blood

• Generating electrical impulses

• Storage of minerals

• Cushioning tissues from blunt force

Tags

NGSS.HS-LS1-7

What is the name of the outermost layer of connective tissue surrounding a skeletal muscle?

• Sarcolemma

• Endomysium

• Perimysium

• Epimysium

Myofibrils are composed primarily of__________.

• fascia and tendons

• troponin and tropomyosin

• perimysium and endomysium

• actin and myosin

What causes the striated appearance of skeletal muscle fibers?

• Location of the cisternae

• Organization of components of the sarcomeres

• Position of the sarcoplasmic reticulum network

• Arrangement of transverse tubules

What is a function of transverse tubules?

• To store calcium ions needed for activating tropomyosin

• To connect actin to the myosin filaments

• To transmit action potentials (impulses) into the cell interior

• To store sodium ions needed to initiate an action potential at the cell surface

Which of these options lists the structures in order, from deepest to most superficial?

• Fascia, epimysium, perimysium, endomysium

• Fascia, endomysium, perimysium, epimysium

• Endomysium, perimysium, epimysium, fascia

• Perimysium, epimysium, endomysium, fascia

What is the function of acetylcholinesterase?

• To serve as precursor for production of acetylcholine

• To breakdown acetylcholine

• To be secreted from the axon terminal

• To bind to actin when active sites are revealed

What is the cause of rigor mortis that occurs in skeletal muscles a few hours after death?

• Continued neural activity that produces sustained contractions

• An increase in ATP and decreased membrane permeability to calcium

• A decrease in ATP and increased membrane permeability to calcium

• An increase in ATP in the cells

A runner collapses during their 800-meter race. A medical exam finds that they have lost the ability to plantar flex at the ankle. What muscle has most likely been injured?

• Gastrocnemius

• Biceps femoris

• Tibialis anterior

• Semimembranosus