MUSCULAR SYSTEM

Question 2

A band

Answer 2

The dark band in a sarcomere composed of overlapping thick myosin filaments and thin actin filaments.

Question 3

Abductor muscle

Answer 3

A muscle that moves a body part away from the midline.

Question 4

Actin filament

Answer 4

A thin protein filament that is a component of the cytoskeleton and muscle fibers involved in cell movement and contraction.

Question 5

Adductor muscle

Answer 5

A muscle that moves a body part toward the midline.

Question 6

Adenosine diphosphate (ADP)

Answer 6

A molecule that is produced when ATP releases energy by losing a phosphate group.

Question 7

Adenosine triphosphate (ATP)

Answer 7

The main energy currency of the cell providing energy for cellular processes including muscle contraction.

Question 8

Aerobic metabolism

Answer 8

Metabolic processes that require oxygen to produce ATP yielding a large amount of energy.

Question 9

Agonist

Answer 9

A muscle that is primarily responsible for a specific movement also called the prime mover.

Question 10

Anaerobic metabolism

Answer 10

Metabolic processes that do not require oxygen to produce ATP yielding a small amount of energy rapidly.

Question 11

Antagonist

Answer 11

A muscle that opposes the action of an agonist.

Question 12

Aponeuroses

Answer 12

Broad flat sheets of connective tissue that attach muscles to bones or other muscles.

Question 13

Brachium

Answer 13

The upper arm region containing muscles like the biceps and triceps.

Question 14

Cardiac muscle

Answer 14

Striated involuntary muscle tissue found only in the heart responsible for pumping blood.

Question 15

Creatine phosphate (CP)

Answer 15

A high-energy phosphate molecule stored in muscles that can quickly donate a phosphate to ADP to regenerate ATP during intense activity.

Question 16

Cross-bridge

Answer 16

The connection formed between the myosin heads of thick filaments and the binding sites on actin filaments during muscle contraction.

Question 17

Cutaneous muscle

Answer 17

A muscle located within the skin that causes movement of the skin.

Question 18

Dense body

Answer 18

Attachment points for actin filaments in smooth muscle cells analogous to Z lines in skeletal muscle.

Question 19

Diaphragm

Answer 19

A dome-shaped muscle located at the base of the chest cavity that is the primary muscle of respiration.

Question 20

Endomysium

Answer 20

The delicate connective tissue layer that surrounds individual muscle fibers.

Question 21

Epimysium

Answer 21

The outermost layer of dense connective tissue that surrounds an entire muscle.

Question 22

Expiratory muscle

Answer 22

A muscle that aids in expelling air from the lungs during exhalation e.g. internal intercostals abdominal muscles.

Question 23

Fascicle

Answer 23

A bundle of muscle fibers within a muscle surrounded by perimysium.

Question 24

Fixator

Answer 24

A muscle that stabilizes a joint to allow another muscle to perform a movement effectively.

Question 25

H band

Answer 25

The light region in the center of the A band of a sarcomere where only thick myosin filaments are present.

Question 26

I band

Answer 26

The light band in a sarcomere composed of thin actin filaments and Z lines.

Question 27

Inspiratory muscle

Answer 27

A muscle that aids in drawing air into the lungs during inhalation e.g. diaphragm external intercostals.

Question 28

Intercalated disc

Answer 28

Specialized cell junctions found in cardiac muscle that connect adjacent myocardial cells allowing for rapid electrical communication and coordinated contraction.

Question 29

Intramuscular

Answer 29

Located or occurring within a muscle.

Question 30

Involuntary muscle

Answer 30

Muscle tissue that is not under conscious control includes smooth muscle and cardiac muscle.

Question 31

Involuntary striated muscle

Answer 31

Muscle tissue that has a striped appearance but is not under conscious control characteristic of cardiac muscle.

Question 32

Lactic acid

Answer 32

A byproduct of anaerobic metabolism in muscle cells that can contribute to muscle fatigue.

Question 33

Linea alba

Answer 33

A fibrous band of connective tissue that runs vertically along the midline of the abdomen serving as an attachment point for abdominal muscles.

Question 34

Motor unit

Answer 34

A single motor neuron and all the muscle fibers it innervates which contract together when the neuron is stimulated.

Question 35

Multi-unit smooth muscle

Answer 35

Smooth muscle tissue in which individual muscle cells are innervated and contract independently allowing for fine precise movements found in the iris of the eye and arrector pili muscles.

Question 36

Muscle

Answer 36

A tissue composed of cells that have the special ability to shorten or contract in order to produce movement of the body parts. 1

Question 37

Myofibril

Answer 37

A rod-like bundle of contractile filaments actin and myosin found in muscle cells.

Question 38

Myoglobin

Answer 38

A protein in muscle cells that stores and transports oxygen.

Question 39

Myosin filament

Answer 39

A thick protein filament that is a component of muscle fibers involved in muscle contraction.

Question 40

Neuromuscular junction

Answer 40

The synapse or point of contact where a motor neuron communicates with a muscle fiber transmitting a signal for contraction.

Question 41

Nonstriated involuntary muscle

Answer 41

Muscle tissue that lacks striations and is not under conscious control smooth muscle.

Question 42

Perimysium

Answer 42

The connective tissue layer that surrounds a fascicle a bundle of muscle fibers.

Question 43

Sarcolemma

Answer 43

The plasma membrane of a muscle fiber.

Question 44

Sarcomere

Answer 44

The basic contractile unit of striated muscle tissue the region between two Z lines.

Question 45

Sarcoplasm

Answer 45

The cytoplasm of a muscle fiber.

Question 46

Sarcoplasmic reticulum

Answer 46

A specialized type of endoplasmic reticulum in muscle cells that stores and releases calcium ions 2 essential for muscle contraction.

Question 47

Sinoatrial node

Answer 47

A specialized region of cardiac muscle tissue in the right atrium of the heart that acts as the natural pacemaker initiating the electrical impulses that trigger heartbeats.

Question 48

Skeletal muscle

Answer 48

Striated voluntary muscle tissue attached to bones responsible for voluntary movement.

Question 49

Skeletal muscle fiber

Answer 49

A single muscle cell of skeletal muscle tissue.

Question 50

Smooth muscle

Answer 50

Nonstriated involuntary muscle tissue found in the walls of internal organs and blood vessels responsible for involuntary contractions.

Question 51

Synergist

Answer 51

A muscle that assists an agonist in performing a movement.

Question 52

Tendon

Answer 52

A tough band of fibrous connective tissue that connects muscle to bone.

Question 53

Transverse tubule (T tubule)

Answer 53

An invagination of the sarcolemma that extends into the muscle fiber transmitting electrical impulses from the surface to the sarcoplasmic reticulum.

Question 54

Twitch contraction

Answer 54

A single rapid contraction and relaxation of a muscle fiber in response to a single stimulus.

Question 55

Viscera

Answer 55

The internal organs of the body particularly those in the abdomen.

Question 56

Visceral smooth muscle

Answer 56

Smooth muscle tissue found in the walls of internal organs viscera typically exhibiting slow sustained contractions and connected by gap junctions allowing coordinated movement.

Question 57

Voluntary striated muscle

Answer 57

Muscle tissue that has a striped appearance and is under conscious control skeletal muscle.

Question 58

Z line

Answer 58

A dense protein structure that marks the boundaries of a sarcomere and serves as an attachment point for thin actin filaments.