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DTCC Anatomy & Physiology > Muscles Classwork > Flashcards

Flashcards in Muscles Classwork Deck (59)
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1
Q

muscles are so important because they make up how much of the body’s mass

A

nearly half of the body’s mass

2
Q

what can muscles transform chemical energy into

A

can transform energy in the cells, called ATP into directed mechanical energy which is capable of exerting force

3
Q

whats the 3 types of muscle

A

cardiac smooth skeletal

4
Q

what are muscles 4 main characteristics

A

exciteabli contractibility Extensibility Elasticity

5
Q

Excitability

A

(responsiveness) ability to receive and respond to stimuli

6
Q

Contractability

A

Ability to shorten forcibly when stimulated

7
Q

Extensibility

A

ability to be stretched

8
Q

Elasticity

A

ability to recoil to resting length

9
Q

what is skeletal muscle

A

an organ made up of diff. tissues with three features: NERVE AND BLOOD SUPPLY, CONNECTIVE TISSUE SHEATHS, and ATTATCHMENTS

10
Q

each muscle receives a nerve, artery, and vein. How are they consciously controlled

A

Consciously controlled skeletal muscle has nerves supplying every fiber to control activity

11
Q

contracting muscle fibers require huge amounts of what two things?

A

oxygen and nutrients they also need waste products to be removed quickly

12
Q

what are the two functional groups

A

Prime mover(agonist) Antagonist

13
Q

Prime mover

A

aka Agonist Major responsibility for producing specific movement

14
Q

Antagonist

A

Opposes or reverses particular movement

15
Q

Prime mover and antagonist are located where

A

opposite sides of joint across which they act

16
Q

Synergist

A

helps prime movers adds extra force to same movement reduces undesireable or unnecessary movement

17
Q

Fixator

A

-Synergist that immobilizes bone or muscles origin -Gives prime mover stable base on which to act

18
Q

Some muscle may be….

A
  • prime mover of one movement - antagonist for diff. movement -synergist for third movement
19
Q

whats the 7 ways muscles are named?

A

location, shape, size, direction of muscle pairs(fascicles), number of origins, location of attatchments Muscle action

20
Q

muscle location

A

bone or body region w/ which muscle associated ex: temporalis

21
Q

whats an ex. of a muscle named for the direction of muscle fibers

A

Rectus, transversus -All skeletal muscles consist of fascicles (bundles of fibers) -fibers arrangements vary, resulting in muscles w/ different shapes and functional capabilities -the most common patterns of arrangements

22
Q

whats the 3 most common patterns of arrangement

A

Circular Congruent Parrallell Pennate

23
Q

insertion

A

attatchment to movable bone

24
Q

origin

A

attatchment to immovable or less movable bone

25
Q

direct attachment

A

epimysium fused to periosteum of bone or perichondrium of cartilage

26
Q

Indirect

A

connective tissue wrappings extend beyond muscle as ropelike tendon or sheet-like aponeurosis

27
Q

describe Muscle Action

A

-when muscles are named for the movement they produced action words such as flexor,extensor, or abductor

28
Q

what is each skeletal muscle and muscle fiber covered in

A

Connective tissue

29
Q

what do connective tissue sheaths do

A

support cells and reinforce whole muscle

30
Q

whats the order of sheaths from external to internal

A

epimysium perimysium Endomysium

31
Q

Epimysium

A

Dense irregular connective tissue surrounding entire muscle; may bend with fascia

32
Q

Perimysium

A

Fibrous connective tissue surrounding fascicles(groups of muscle fibers)

33
Q

Endomysium

A

Fine areolar connective tissue surrounding each muscle fiber

34
Q

Whats the characteristics of skeletal muscle

A

long cylindrical cells that contain multiple nuclei

35
Q

Sarcolemma

A

muscle fiber plasma membrane

36
Q

sarcoplasm

A

muscle fiber cytoplasm

37
Q

what does skeletal muscle contain

A

contains many glycosomes for glycogen storage, as well as myoglobin for oxygen storage

38
Q

what are the 3 modified organelles

A

Myofibrils

Sarcoplasmic reticulum

T Tubules

39
Q

describe Myofibrils

A

densely packed, rodlike elements

  • single muscle fiber can contain 1000s
  • Accounts for 80% of muscle cell volume
40
Q

What are myofibrils features

A

Striations

sarcomeres

myofilaments

41
Q

Striations

A

stripes formed from repeating series of dark and light bands along length of each myofibril

42
Q

what are A bands

A

a-dark regions

43
Q

whats the h zone

A

lighter region in middle od dark A band

44
Q

whats the M line

A

line of protein(myomesin) that bisects H zone vertically

45
Q

whats the I band

A

Lighter regions -z disc(line)- coin-shaped sheet of proteins on midline of light

46
Q

list 4 things about a sarcomere

A

-Smallest contractile unit (functional unit) of muscle fiber -Contains A band w/ half of an I band at each end -Consists of area between Z discs -Indivisual sarcomeres align end to end along myofribril, like boxcars of train -band

47
Q

what are myofiliments

A

orderly arrangement of actin and myosin myofilaments within sarcomere

48
Q

Actin

A

thin filaments -extend length of A and -Anchored to Z discs

49
Q

Myosin

A

thick filaments -Extend length of A band -Connected M line -Sarcomere cross section shows hexagonal arrangement of one thick filament surrounded by 6 thin filaments

50
Q

whats the molecular composition of myofilaments( in thick filaments)

A

thick filaments: composed of protein myosin that contains two heavy and four light polypeptide chains

51
Q

what does the molecular composition of myofiliaments contain( in thick filaments)

A

-heavy chains intertwine to form myosin tail Light chains form myosin globular head

–During contraction, heads link thick and thin filaments together, forming cross bridges

52
Q

in molecular composition of myofilaments, what are offset of each other (in thick filaments)

A

Myosins are offset from each other, resulting in staggered array of heads at different points along thick filament

53
Q

In molecular composition of myofilaments, what are the thin filaments made up of

A

Composed of fibrous protein actin

54
Q

what role does actin play in molecular composition of myofilaments in thin filaments

A

Actin is ploypeptide made up of kidney-shaped G actin (globular) subunits

55
Q

what role does G actin play in molecular composition of myofilaments (in thin filaments)

A

G actin subunits bears active sites dor myosin head attatchement during contraction

-G actin subunits link together to form long, fibrous F actin(filamentous

56
Q

what role does F actin play in molecular composition of thin filaments

A

Two F actin strands twist together to form a thin filaments

57
Q

whats tropomyosin and troponin

A

regulatory proteins bound to actin

58
Q

what does each thick filament consist of

A

many myosin molecules whose heads protrude at opposite ends of the filament

59
Q

what does a thin filament consists of two strands of

A

actin subunits twisted into a helix plus two types of regulatory proteins (troponin and tropomyosin)