Ch 9 & 10 Vocab

Question 1

Contraction

Answer 1

The process where muscles shorten and generate force.

Question 2

Sarcomere

Answer 2

The basic unit of a muscle, made up of actin and myosin, responsible for contraction.

Question 3

Sarcolemma

Answer 3

The membrane surrounding a muscle fiber.

Question 4

Sarcoplasmic Reticulum

Answer 4

A structure that stores calcium ions, which are crucial for muscle contraction.

Question 5

Sarcoplasm

Answer 5

The cytoplasm of a muscle cell, containing nutrients and organelles.

Question 6

Muscle Fiber

Answer 6

A single muscle cell, capable of contraction.

Question 7

Myoblast

Answer 7

An immature muscle cell that can develop into a muscle fiber.

Question 8

Myofibril

Answer 8

A long, thread-like structure within a muscle fiber, made up of sarcomeres.

Question 9

Myofilament

Answer 9

The filaments (actin and myosin) that make up myofibrils and are responsible for muscle contraction.

Question 10

Fascicle

Answer 10

A bundle of muscle fibers grouped together.

Question 11

Tendon

Answer 11

The connective tissue that attaches muscle to bone.

Question 12

Endomysium

Answer 12

The thin layer of connective tissue that surrounds individual muscle fibers.

Question 13

Perimysium

Answer 13

The connective tissue that surrounds a fascicle of muscle fibers.

Question 14

Epimysium

Answer 14

The outer layer of connective tissue that surrounds the entire muscle.

Question 15

Actin

Answer 15

A protein that forms thin filaments in muscle fibers and plays a key role in contraction.

Question 16

Myosin

Answer 16

A protein that forms thick filaments in muscle fibers and interacts with actin to produce contraction.

Question 17

Myosin Heads

Answer 17

Projections on myosin that attach to actin during contraction.

Question 18

Cross-Bridges

Answer 18

Connections formed between myosin heads and actin during contraction.

Question 19

Neuromuscular Junction

Answer 19

The site where a motor neuron communicates with a muscle fiber.

Question 20

Motor End Plate

Answer 20

The part of the muscle fiber membrane that receives signals from the neuron.

Question 21

Acetylcholine

Answer 21

A neurotransmitter released at the neuromuscular junction to trigger muscle contraction.

Question 22

Troponin

Answer 22

A protein that helps regulate muscle contraction by binding calcium ions.

Question 23

Tropomyosin

Answer 23

A protein that blocks actin sites for myosin, preventing contraction until calcium is present.

Question 24

Calcium Ions

Answer 24

Ions that, when released from the sarcoplasmic reticulum, trigger muscle contraction.

Question 25

Sliding Filament Theory

Answer 25

The explanation of how muscles contract by the sliding of actin over myosin.

Question 26

Membrane Potential

Answer 26

The electrical charge difference across a cell membrane.

Question 27

Transverse Tubules

Answer 27

Extensions of the sarcolemma that help transmit electrical signals into the muscle fiber.

Question 28

Triads

Answer 28

Structures formed by a transverse tubule and two adjacent sarcoplasmic reticulum sacs, important for muscle contraction.

Question 29

Depolarization

Answer 29

The process of a muscle cell’s membrane potential becoming less negative, leading to contraction.

Question 30

Repolarization

Answer 30

The return of the membrane potential to its resting state after contraction.

Question 31

Hyperpolarization

Answer 31

When the membrane potential becomes more negative than the resting state

Question 32

Isotonic

Answer 32

Muscle contractions where the muscle changes length (shortens or lengthens) while generating force.

Question 33

Isometric

Answer 33

Muscle contractions where the muscle generates force without changing length.

Question 34

Tetanus

Answer 34

A sustained muscle contraction due to rapid stimulation.

Question 35

Motor Unit

Answer 35

A single motor neuron and all the muscle fibers it controls.

Question 36

Recruitment

Answer 36

The process of activating more motor units to increase muscle force.

Question 37

Fast Fibers

Answer 37

Muscle fibers that contract quickly but tire out fast; good for short bursts of strength.

Question 38

Slow Fibers

Answer 38

Muscle fibers that contract slowly but are more resistant to fatigue; good for endurance activities.

Question 39

Cori Cycle

Answer 39

The process where lactate produced in muscles is converted back to glucose in the liver.

Question 40

Appendicular muscle

Answer 40

those in the limbs

Question 41

Axial Muscle

Answer 41

are in the trunk and head