Muscular System

Question 1

Skeletal muscle

Answer 1

Controlled by the conscious mind and moves the bones of the skeleton, also referred to as voluntary striated muscle

Question 2

Cardiac muscle

Answer 2

Makes up the structure of the heart and controls the heart to beat

Question 3

Smooth muscle

Answer 3

Found all over the body in places such as the eyes, the air passageways in the lungs, the stomach and intestines, the urinary bladder, the blood vessels, and the reproductive tract

Question 4

Epimysium

Answer 4

A fibrous connective sheath surrounding skeletal muscle

Question 5

Aponeuroses

Answer 5

Broad sheet of fibrous connective tissue which help muscles attach to other muscles or bones

Question 6

Linea alba

Answer 6

The most prominent aponeurosis, runs lengthwise between the muscles on an animal’s ventral midline

Question 7

Agonist (or prime mover)

Answer 7

Used to describe a muscle or muscle group that directly produces a desired movement

Question 8

Antagonist

Answer 8

A muscle or muscle group that directly opposes the action of an agonist

Question 9

Synergist

Answer 9

A skeletal muscle that contracts at the same time as an agonist and assists it in carrying out its action

Question 10

Fixator muscles

Answer 10

Stabilize joints to allow other movements to take place

Question 11

Sarcolemma

Answer 11

Muscle cell membrane

Question 12

Sarcoplasmic reticulum

Answer 12

A storage of organelle for calcium ions

Question 13

Myofibrils

Answer 13

Hundreds or thousands creates most of the volume of one skeletal muscle fiber, composed of thousands of even tinier protein filaments

Question 14

Transverse tubules (T-tubules)

Answer 14

A system of tubules that extend in from the sarcolemma

Question 15

Sarcomere

Answer 15

The basic contracting unit of skeletal muscle

Question 16

Z line or Z disc

Answer 16

A disc present on each end of a sarcomere

Question 17

Actin

Answer 17

One protein filament responsible for contraction. Thin, attach to the Z lines and extend toward the center of the sarcomere but do not meet

Question 18

Myosin

Answer 18

A protein filament responsible for contraction within a sarcomere. Thick, appear to float in the middle of the sarcomere between parallel actin fibers. Do not connect to Z lines

Question 19

I bands

Answer 19

Large light-colored bands present microscopically in a myofibril, made up of thin actin filaments

Question 20

A bands

Answer 20

Darker bands present between I bands, areas where the thick myosin filaments and thin actin filaments overlap

Question 21

H band

Answer 21

The light-colored area located in the middle of the A band, made up of myosin filaments only, with no overlapping actin filaments, so it does not cover the entire width of the myosin filament

Question 22

Cross-bridges

Answer 22

Two globular heads attached to a twisted tail produced by the myosin molecule, interacts with the actin to shorten the sarcomere during the muscle contraction

Question 23

Neuromuscular junctions

Answer 23

Sites where the ends of motor nerve fibers connect to muscle fibers

Question 24

Motor unit

Answer 24

Used to describe one nerve fiber and all the muscle fibers it innervates

Question 25

Endomysium

Answer 25

A delicate connective tissue layer that surrounds each individual skeletal muscle fiber, composed of fine, reticular fibers

Question 26

Fasicles

Answer 26

Groups of skeletal muscles, bound together by a tougher connective tissue layer called the perimysium

Question 27

Perimysium

Answer 27

Tough connective tissue layer composed of reticular fibers and thick collagen fibers

Question 28

Epimysium

Answer 28

A fibrous connective tissue layer composed largely of tough collagen fibers, surrounds groups of muscles

Question 29

All-or-nothing principle

Answer 29

When an individual muscle fiber either contracts completely when it receives a nerve impulse, or it does not contract at all

Question 30

Twitch contraction

Answer 30

A single muscle contraction, can be divided into three phases

Question 31

Three phases of twitch contraction

Answer 31

The latent phase, the contracting phase, and the relaxation phase

Question 32

Creatine phosphate (CP)

Answer 32

The "battery charger" that converts ADP back to ATP, a compound in muscle fibers

Question 33

Myoglobin

Answer 33

Stored oxygen attached to large protein molecules

Question 34

Aerobic metabolism

Answer 34

The process when strenuous muscle contractions begin to deplete the oxygen supply to a muscle fiber, myoglobin can release its stash of oxygen molecules to resupply the fiber

Question 35

Cutaneous muscle

Answer 35

Skin muscle, when an animal twitches its skin to get rid of an insect

Question 36

Intercalated discs

Answer 36

Firm, end-to-end attachments between cardiac muscle cells, also transmits impulses from cell to cell to allow large groups of cardiac muscle cells to contract in a coordinated manner

Question 37

Sinoatrial (SA) node

Answer 37

The hearts "pacemaker", located in the wall of the right atrium. The impulse that starts each heartbeat begins here

Question 38

Two main forms of smooth muscle

Answer 38

Visceral smooth muscle and multi-unit smooth muscle