Prcatice 2: Muscle Structure

Match these terms with the correct statement or definition.

• Contractility

• Ability to recoil to original resting length after being stretched.

• Excitability

• Ability to shorten with a force.

• Elasticity

• The capacity to respond to a stimulus.

• Extensibility

• Ability to be stretched.

Match these terms with the correct statement or definition.

• Perimysium.

• Connective tissue that surrounds a muscle fiber.

• Endomysium.

• Muscle bundle.

• Muscle fasiculus

• Connective tissue that surrounds muscle fasciculi.

• Muscle fiber

• Connective tissue sheath that surrounds each skeletal muscle.

• Epimysium.

• Single muscle cell; makes up muscle fasciculi.

Match the following.

• Tropomyosin

• Thick myofilaments which resemble bundles of golf clubs.

• Myofibril

• Thread-like structure that extends from one end of the muscle

  fiber to the other.

• Troponin

• Provide calcium binding sites on actin myofilaments.

• Myosin

• Thin myofilament which resembles two minute strands of

  pearls twisted together.

• Actin

• Covers and uncovers attachment sites for myosin on actin

  myofilaments.

The basic structural and functional unit of the muscle is

• the sarcomere.

• myosin.

• actin.

• a muscle fiber.

Forms an attachment site for actin myofilaments; the end of the sarcomere.

• troponin

• cross-bridge

• z-disk

• myofibril

Match the following.

• Sarcoplasm

• Invaginations (indentions) of the sarcolemma that wrap around sarcomeres.

• Sarcolemma

• The cytoplasm of a muscle fiber.

• Sarcoplasmic reticulum

• The cell membrane of a muscle fiber.

• T tubules

• Highly organized, smooth endoplasmic reticulum; contains

  high concentrations of calcium.

Match the numbered label with the term.

• label 2

• endomysium

• label 1

• Epimysium

• label 4

• perimysium

Tags

NGSS.HS-LS1-2

Match the numbered label with the term.

• label 3

• the myofilament actin

• label 8

• the myofilament myosin

• label 10

• fasciculi

• label 5

• muscle fiber

• label 9

• myofibrils

Tags

NGSS.HS-LS1-2

NGSS.HS-LS1-4

Label 7 is pointing to the ​ (a)   , while label 6 is pointing to the ​ (b)   . The striations are made by many ​ (c)   lined together.

• t-tubules
• sarcoplasmic reticulum
• sarcomeres

Match the structure to the label.

• label 1

• actin

• label 2

• sarcomere

• label 4

• myosin

• label 3

• z disk