Question 1

Which of the following is NOT a function of skeletal muscle tissue?

Accepted Answer

Secretion of digestive enzymes

Question 2

Which connective tissue sheath surrounds an individual muscle fiber?

Accepted Answer

Endomysium

Question 3

What is the primary contractile protein found in thick filaments of skeletal muscle?

Accepted Answer

Myosin

Question 4

Which structure is the functional and structural unit of a skeletal muscle fiber?

Accepted Answer

Sarcomere

Question 5

During muscle contraction, which theory explains the interaction between thick and thin filaments?

Accepted Answer

Sliding filament theory

Question 6

Which protein blocks the active sites on actin, preventing actin-myosin interaction in a relaxed muscle?

Accepted Answer

Tropomyosin

Question 7

What is the role of calcium ions ($$Ca^{2+}) in $$skeletal muscle contraction?

Accepted Answer

They bind to troponin, causing conformational changes that expose actin active sites

Question 8

Which connective tissue sheath is responsible for surrounding the entire muscle and separating it from surrounding tissues?

Accepted Answer

Epimysium

Question 9

Which of the following best describes the organization of skeletal muscle from largest to smallest structure?

Accepted Answer

Skeletal muscle → Muscle fascicle → Muscle fiber → Myofibril

Question 10

Which of the following is TRUE regarding the sarcolemma?

Accepted Answer

It is the cell membrane of a muscle cell

Question 11

What is the main function of the sarcoplasmic reticulum (SR) in skeletal muscle fibers?

Accepted Answer

To store and regulate $$Ca^{2+}$$ concentration

Question 12

Which protein is responsible for holding F actin strands together in thin filaments?

Accepted Answer

Nebulin

Question 13

Which of the following statements about skeletal muscle fibers is CORRECT?

Accepted Answer

They are multinucleated and very long

Question 14

What is the role of titin in the sarcomere?

Accepted Answer

It stabilizes thick filaments and centers them between thin filaments

Question 15

Which of the following best describes the arrangement of myosin heads in a thick filament?

Accepted Answer

Heads on one half angle to the left, heads on the other half angle to the right

Question 16

Which structure forms the boundary of a sarcomere?

Accepted Answer

Z line

Question 17

What is the primary function of transverse tubules (T tubules) in skeletal muscle fibers?

Accepted Answer

To transmit action potentials deep into the muscle fiber

Question 18

Which of the following is a regulatory protein found in thin filaments that binds calcium ions?

Accepted Answer

Troponin

Question 19

During contraction, what happens when myosin heads interact with actin filaments?

Accepted Answer

They form cross-bridges and pivot, producing a power stroke

Question 20

Which of the following best describes the composition of a muscle fascicle?

Accepted Answer

A bundle of muscle fibers

Muscle Tissue & The Muscular System: Structure and Function of Skeletal Muscle

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