Muscles Study Guide

The functions of skeletal muscles include:

• Movement and posture maintenance

• Hormone production

• Blood filtration

• Nutrient absorption

Myofibrils are composed of:

• actin and myosin

• collagen and elastin

• keratin and fibrin

• tubulin and dynein

Nerves and blood vessels that service the muscle fibers are located in the connective tissues of the _____________________________.

• muscle

• bone

• skin

• cartilage

The delicate connective tissue that surrounds the skeletal muscles fibers and ties adjacent muscle fibers together is the ____________________________.

• endomysium

• perimysium

• epimysium

• fascia

Neurotransmitters are stored in:

• dendrites

• axon terminals

• cell body

• myelin sheath

The command to contract is distributed throughout the muscle fiber by the:

• sarcoplasmic reticulum

• T-tubules

• mitochondria

• nucleus

The cytoplasm of a skeletal muscle fiber is called the:

• sarcoplasm

• myoplasm

• endoplasm

• cytoplasm

At rest, the tropomyosin molecule is held in place by ____________________________.

• (Answer not provided in the text)

• actin filaments

• myosin heads

• calcium ions

When calcium ion binds to troponin, what happens next?

• Muscle contraction is initiated

• Troponin releases calcium

• Actin and myosin filaments separate

• ATP is hydrolyzed

In response to action potentials arriving from the transverse tubules, the sarcoplasmic reticulum releases:

• Calcium ions

• Sodium ions

• Potassium ions

• Chloride ions