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Flashcards in Muscular System Deck (58)
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1
Q

Muscular system is only composed of..

A

skeletal muscle (not cardiac or smooth)

2
Q

Skeletal muscle cells are called..

A

fibers

3
Q

Fascicle is a..

A

group of fibers

4
Q

Whole muscle is a..

A

group of fascicle

5
Q

CT components of skeletal muscle

A
  • Fascia
  • Tendons
  • Aponeuroses
6
Q

Fascia

A

connective tissue enclosing muscle of a group of muscles

7
Q

Epimysium

A

surrounds entire muscle of fascia

8
Q

Perimysium

A

wraps all of the fascicles

9
Q

Endomysium

A

wraps each individual muscle fiber

10
Q

Tendons

A
  • connective tissue that attaches muscle to bone

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

11
Q

Each myofibril is divided into contractile units called….

A

called sarcomeres.

the sarcomeres join end to end to form the myofibril

12
Q

Aponeurosis

A

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

13
Q

Skeletal muscle fiber structure

A

long, cylindrical multinucleate cells

14
Q

Parts of skeletal muscle fiber structure

A
  • Sarcolemma
  • Sarcoplasm
  • T-tubules
  • Sarcoplasmic reticulum
15
Q

Sarcolemma =

A

Specialized muscle cell plasma membrane

16
Q

Sarcoplasm =

A

cytoplasm of muscle fibre

17
Q

Myofibrils

A
  • intracellular structures
  • Organelles that form the muscle fiber
  • Made up of bundles of myofilaments
18
Q

Myofilaments make up myofibrils and come in 2 forms

A
  • thin filaments

- thick filaments

19
Q

Thin filaments composed of

A
  • actin (functions in contraction)
  • tropomyosin (stabilizes actin until contraction occurs)
  • troponin (regulate contraction by binding to calcium and actin)
20
Q

Thick filaments composed of..

A

myosin (rod like tail and 2 globular heads)

21
Q

Thick filaments

A

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

22
Q

The myofilaments create ___ and ____ bands of the sarcomere

A

dark; light (provide muscle w striated appearance)

23
Q

Each sarcomere contains ..

A
  • A band
  • H zone
  • I band
  • Z discs
  • M line
  • T tubules
24
Q

“A” band

A

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

25
Q

H zone

A

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

26
Q

I band

A

light and composed of actin, Titian and Z disk

27
Q

Z discs are in the centre of _ band

A

I

28
Q

Z discs

A

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

29
Q

M line

A

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

30
Q

Myofibrils

A

sarcomeres joined end to end at Z discs

31
Q

T-tubules (transverse tubules)

A

continuations of sarcolemma that extend deep into fiber

32
Q

What t-tubules do

A

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

33
Q

Sarcoplasmic reticulum

A

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

34
Q

The origin of the muscle is on..

A

the stationary bone

35
Q

The insertion of the muscle is on the..

A

moving bone

36
Q

Agonists are the..

A

major muscle producing the movement

37
Q

Synergists act to..

A

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

38
Q

Antagonists act to oppose the..

A

action of agonist (contraction inhibited when agonist contracts)

39
Q

Lever system

A

bone and muscle interact at joint to accomplish moving

40
Q

The lever is the..

A

bone

41
Q

The fulcrum is the..

A

joint

42
Q

Effort is the..

A

contraction of agonist

43
Q

Resistance opposes..

A

movement of the load

44
Q

Flexors

A

decrease angle between 2 bones

45
Q

Extensors

A

increase angle between 2 bones

46
Q

Abductors

A

move limb away from midline

47
Q

Adductors

A

move limb toward midline

48
Q

Deltoid

A

triangular shape of muscle

49
Q

Trapezius

A

trapezoid shape of muscle (no two sides parallel)

50
Q

Break down origin and insertion of sternocleidomastoid

A

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

51
Q

To describe relative size we use..

A
  • maximus
  • medius
  • minimus
52
Q

Direction of fibers

A
  • rectus (straight) ||
  • transversus (90 degree angle relative to a reference line)
  • external (not at a 90 degree angle or straight relative to reference line) \ //
53
Q

Characteristics of skeletal muscle

A
  • under voluntary control
  • striated
  • attached primarily to bone
  • produces bodily movements
  • release heat as a byproduct of contraction
54
Q

Triads

A

T-tubules associated with 2 terminal cisternae

55
Q

Sarcomeres are the ..

A

contractile unit of muscle

56
Q

Myofibrils are divided intro..

A

sarcomeres

57
Q

Muscles and bone can produce movement by ..

A
  • muscles pulling on bone when they contract (origin/insertion)
  • using group action (agonists, antagonists, and synergists)
  • forming lever systems
58
Q

Number of origins used to describe muscles

A
  • 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