Muscular System

Question 1

Muscular system is only composed of..

Answer 1

skeletal muscle (not cardiac or smooth)

Question 2

Skeletal muscle cells are called..

Answer 2

fibers

Question 3

Fascicle is a..

Answer 3

group of fibers

Question 4

Whole muscle is a..

Answer 4

group of fascicle

Question 5

CT components of skeletal muscle

Answer 5

• Fascia
• Tendons
• Aponeuroses

Question 6

Fascia

Answer 6

connective tissue enclosing muscle of a group of muscles

Question 7

Epimysium

Answer 7

surrounds entire muscle of fascia

Question 8

Perimysium

Answer 8

wraps all of the fascicles

Question 9

Endomysium

Answer 9

wraps each individual muscle fiber

Question 10

Tendons

Answer 10

• connective tissue that attaches muscle to bone

- extensions of epi, peri, and endomysium covering the muscle

Question 11

Each myofibril is divided into contractile units called….

Answer 11

called sarcomeres.

the sarcomeres join end to end to form the myofibril

Question 12

Aponeurosis

Answer 12

sheet-like tendon, anchors muscle to connective tissue covering of a bone (found in skull)

Question 13

Skeletal muscle fiber structure

Answer 13

long, cylindrical multinucleate cells

Question 14

Parts of skeletal muscle fiber structure

Answer 14

• Sarcolemma
• Sarcoplasm
• T-tubules
• Sarcoplasmic reticulum

Question 15

Sarcolemma =

Answer 15

Specialized muscle cell plasma membrane

Question 16

Sarcoplasm =

Answer 16

cytoplasm of muscle fibre

Question 17

Myofibrils

Answer 17

• intracellular structures
• Organelles that form the muscle fiber
• Made up of bundles of myofilaments

Question 18

Myofilaments make up myofibrils and come in 2 forms

Answer 18

• thin filaments

- thick filaments

Question 19

Thin filaments composed of

Answer 19

• actin (functions in contraction)
• tropomyosin (stabilizes actin until contraction occurs)
• troponin (regulate contraction by binding to calcium and actin)

Question 20

Thick filaments composed of..

Answer 20

myosin (rod like tail and 2 globular heads)

Question 21

Thick filaments

Answer 21

are attached to Z band of sarcomere by titin and the globular head binds towards actin forms cross bridge

Question 22

The myofilaments create ___ and ____ bands of the sarcomere

Answer 22

dark; light (provide muscle w striated appearance)

Question 23

Each sarcomere contains ..

Answer 23

• A band
• H zone
• I band
• Z discs
• M line
• T tubules

Question 24

“A” band

Answer 24

spans the length of the thick filament, its dark and composed of action and myosin

Question 25

H zone

Answer 25

at centre of the A band (light and composed of myosin)

Question 26

I band

Answer 26

light and composed of actin, Titian and Z disk

Question 27

Z discs are in the centre of _ band

Answer 27

I

Question 28

Z discs

Answer 28

connect sarcomeres (2 Z discs/1 sarcomere). thick filaments are connected to the Z disk by Titin protein

Question 29

M line

Answer 29

where myosin tails (thick myofilaments) connect to one another art the centre of the sarcomere

Question 30

Myofibrils

Answer 30

sarcomeres joined end to end at Z discs

Question 31

T-tubules (transverse tubules)

Answer 31

continuations of sarcolemma that extend deep into fiber

Question 32

What t-tubules do

Answer 32

directly encircle myofilaments of myofibrils at junction of A and I bands

Question 33

Sarcoplasmic reticulum

Answer 33

Smooth ER with terminal cisternae (expanded regions near the T tubules)

Question 34

The origin of the muscle is on..

Answer 34

the stationary bone

Question 35

The insertion of the muscle is on the..

Answer 35

moving bone

Question 36

Agonists are the..

Answer 36

major muscle producing the movement

Question 37

Synergists act to..

Answer 37

help the agonist by either providing extra force that's needed or preventing undesirable effects by the agonist

Question 38

Antagonists act to oppose the..

Answer 38

action of agonist (contraction inhibited when agonist contracts)

Question 39

Lever system

Answer 39

bone and muscle interact at joint to accomplish moving

Question 40

The lever is the..

Answer 40

bone

Question 41

The fulcrum is the..

Answer 41

joint

Question 42

Effort is the..

Answer 42

contraction of agonist

Question 43

Resistance opposes..

Answer 43

movement of the load

Question 44

Flexors

Answer 44

decrease angle between 2 bones

Question 45

Extensors

Answer 45

increase angle between 2 bones

Question 46

Abductors

Answer 46

move limb away from midline

Question 47

Adductors

Answer 47

move limb toward midline

Question 48

Deltoid

Answer 48

triangular shape of muscle

Question 49

Trapezius

Answer 49

trapezoid shape of muscle (no two sides parallel)

Question 50

Break down origin and insertion of sternocleidomastoid

Answer 50

-origin: sterno =sternum cleido = clavicle -insertion: mastoid - massed process of temporal bone

Question 51

To describe relative size we use..

Answer 51

- maximus - medius - minimus

Question 52

Direction of fibers

Answer 52

- rectus (straight) || - transversus (90 degree angle relative to a reference line) - external (not at a 90 degree angle or straight relative to reference line) \\ //

Question 53

Characteristics of skeletal muscle

Answer 53

- under voluntary control - striated - attached primarily to bone - produces bodily movements - release heat as a byproduct of contraction

Question 54

Triads

Answer 54

T-tubules associated with 2 terminal cisternae

Question 55

Sarcomeres are the ..

Answer 55

contractile unit of muscle

Question 56

Myofibrils are divided intro..

Answer 56

sarcomeres

Question 57

Muscles and bone can produce movement by ..

Answer 57

- muscles pulling on bone when they contract (origin/insertion) - using group action (agonists, antagonists, and synergists) - forming lever systems

Question 58

Number of origins used to describe muscles

Answer 58

- Biceps brachii: 2 points on the scapula - Triceps brachii: 3 points on the scapula and the humerus - Quadriceps femoris: 4 points on the ileum and the femur