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1
Q

(3 main types of muscle tissue) skeletal- attached to bones/skin
striated: striped - distinct banded pattern throughout muscle; striation is incredibly …
muscles laid out from one … to another, have more or less … configuration

A

even;
joint;
straight

2
Q

(3 main types of muscle tissue) cardiac:
striated- not in the same way as skeletal
laid out in … around the heart – causes some muscle fibers to go off at an angle

A

spirals

3
Q

(3 main types of muscle tissue) smooth: doesn’t have ability to contract as … or as … as skeletal/cardiac muscle

A

quickly; forcefully

4
Q

(3 main types of muscle tissue) smooth: present in .., …, and muscles that line major … in …–> tissues that respond to internal signals that one has no conscious control over

A

GI tract; bladder; airways; lungs

5
Q

facial muscles tend to sag bc they are attached to other … rather than to bone

A

muscles

6
Q

smooth muscle is about same size as …; contractile apparatus laid out in criss cross pattern, such that when it contracts it both gets less … and less ..

A

skin cell; wide; long

7
Q

(muscle tissue) can become … and can then contract –> shortens in length
has ability to extend beyond resting length
can recoil on its own if its extended beyond a certain limit
flexibility per person is related to … of one’s muscles - innate feature, can’t be learned

A

excited;

extensibility

8
Q

great deal of energy exerted to maintain …, but it’s not noticed because we’re used to it

A

body position

9
Q

muscle stabilizes joints and … system

most complex joint system is that of the …

A

skeletal;

knee

10
Q

muscles allow for heat generation via shivering:

only source of generating … for humans

A

additional heat

11
Q

“white” pieces around muscle is mostly

A

protein

12
Q

in direct muscle attachment there is typically no need for muscle to extend all the way to the …; can actually be hindrance

A

end of the bone

13
Q

fingers are entirely … - no …

A

tendons; muscle

14
Q

there are muscles in palms

muscles in forearm extend … up through to fingers –> using forearms when …

A

indirect tendons up through to fingers;

moving fingers

15
Q

(muscle tissue) epimysium contains all of the …, …, …, etc

A

blood vessels; nerve fibers; connective tissue

16
Q

muscle fibers can be very …, but they are very long

A

skinny

17
Q

muscle cells have multiple nuclei, because as they are developing, muscle cells are … to form long, single cell that is multinucleated

A

fusing together

18
Q

difference between myoglobin and hemoglobin is that myoglobin only has …, whereas hemoglobin has …

A

tertiary structure; quaternary structure

19
Q

sarcoplasmic reticulum is not concerned with …; there as storage

A

protein construction

20
Q

myofibril:
appearance of dark and light striations are result of how underlying architecture is laid out bc skeletal muscle uses two … elements to facilitate contraction

A

cytoskeletal

21
Q

myofibril:
dark bands are there bc of presence of myosin- found in other cell types as single molecule, but in skeletal muscle they band together to form very …, … … structures

A

thick, stiff ropelike

22
Q

myofibril:

light band: consists of actin; when shining light through it, more light goes through because actin fibers are

A

thin

23
Q

myomesin makes up M line in sarcomere:

… such that they cannot move independent of one another –> keeps them lined up

A

holds thick filaments in place

24
Q

I band spans from end of one … to the beginning of another …

A

thick filament; thick filament

25
Q

thick filaments anchored to Z disc by protein called … –> acts like a …

A

titin; spring

26
Q

when individual muscle fibers are stretched, … allows them to return to their original shape
otherwise thick and thin filaments would slide past one another and wouldn’t be able to return back to original configuration
differences in … of this protein can be responsible for variations in flexibility

A

titin;

elasticity

27
Q

H zone slightly lighter than … but not as light as ..

A

A band; I band

28
Q

myosin in muscles have very long .., unlike in other cells, and these wind around one another
… at end
… that walks along actin

A

tails;
myosin head;
motor protein

29
Q

myosin:
works by …
organized in a fashion such that on one side of the M line all of the heads are … and on the other side the heads … – such that during contraction both sides move towards the …

A

hydrolyzing ATP;
pointing in one direction;
point in the other direction;
midline

30
Q

actin is a polymer:

if it is not polymerized it is called … 0 …

A

G actin; globular actin

31
Q

when actin … it forms twisted filament called f actin
G actin doesn’t stack perfectly evenly – when they associate, they associate at an angle so that they twist to forma. spiral - spiral enables action of … and …

A

polymerizes; tropomyosin; troponin

32
Q

(tropomyosin) if muscle is not actively contracting, this protein mimics … to block myosin binding sites
troponin keeps tropomyosin in such a position that by its … nature, it completely obscures all of the actin-myosin binding sites - …

A

spiral;

complementary spiral nature; reinforcer

33
Q

(tropomyosin) for contraction to occur, troponin has to undergo … so it pulls tropomyosin in different direction that changes … of spiral and slides it away from myosin binding sites

A

conformational change;

pitch;

34
Q

SR resembles SER more than RER
no …
form … that isn’t really organized
when muscle wants to contract, this opens up and “dumps” calcium onto entire muscle fiber - does so as evenly as possible

A

embedded ribosomes;

webbing

35
Q

SR:
terminal ends of SR adjacent to …, which carry the electrical signal for muscle fiber contraction and when it reaches SR< this organelle has … on it that change shape to allow for exit of Ca2+

A

T tubules;

voltage-gated receptors

36
Q

T tubules are continuous with sarcolemma - … of sarcolemma that extend into interior of muscle fiber
allows for more … contraction of muscles

A

invaginations;

coordinated

37
Q

without T tubules, muscle contraction would be …, not … and …

A

jerky; smooth; even

38
Q

SR has plates at end called … which are responsible for communicating signal from … to …

A

terminal cisternae; T tubule; SR

39
Q

voltage sensitive proteins in T tubule change … and push on proteins in those terminals, i.e. … proteins

A

shape; foot

40
Q

foot proteins then change shape and opens … and calcium rapidly rushes out of interior of SR and into … of muscle

A

calcium channels;

cytoplasm

41
Q

… contraction: can generate force but not actually move muscle
shortening only happens when generate enough attachments to … to exceed force that’s actually generating them

A

isometric; thin filaments

42
Q

sliding filament model of contraction:
when contraction occurs, all sarcomeres shorten such that there are huge amounts of .. between the two filaments
… doesn’t move, stays in place but pulls actin filaments towards M line, sliding them past thick filaments

A

overlapping; myosin

43
Q

… shorten when contraction, but … do not change length

A

sarcomeres; filaments

44
Q

… do not ever shorten, they are just moving closer together
.. disappears during contraction: no longer center space where there are no … filaments

A

thick and thin filaments;
H line;
actin

45
Q

…: bundle of axons in PNS

A

nerve

46
Q

neuromuscular junction in middle of each fiber:
coordination of contraction more even
otherwise muscle tissue would develop … and potentially lead to …

A

unevenly; muscle tears

47
Q

… is the muscle part of the neuromuscular junction and contains ACh receptors

A

postsynaptic endplate

48
Q

when ACh is released into synaptic cleft it can either be … or become broken down by an enzyme that is constantly released into synaptic cleft - …

A

reabsorbed; acetylcholinesterase

49
Q

action potential in muscle:
delay for slow voltage gated potassium channels is much … than in neurons, because muscle contractions takes longer than sending an action potential down a nerve
… also takes longer

A

longer;

refractory period

50
Q

change in voltage triggers opening of calcium gated channels, calcium will bind to proteins on the …

A

synaptic vesicles

51
Q

synaptic vesicles will line up in a “neat, orderly line” - those that are ready to be released are … at the plasma membrane
calcium binds to proteins that keep the vesicles docked - … (these proteins capture the vesicles and hold them by the plasma membrane)

A

docked;

SNAREs

52
Q

calcium present in extracellular fluid in high concs. - no … because Ca2+ is so universal in its function that we want to maintain tight control over it

A

calcium leak channels

53
Q

synaptic cleft is small so Ach … - this is the initiation of the action potential

A

diffuses instantly

54
Q

ion disturbances that occur through release of calcium ultimately results in …
two …
this process is slower bc the amount of space being covered is much larger as compared to neurons

A

excitation-contraction coupling;

latent periods

55
Q

… channels spread evenly throughout sarcolemma

A

voltage sensitive sodium

56
Q

action potential travels down length of sarcolemma in both directions both … and also in both directions across the …

A

lengthwise; circumference

57
Q

… are embedded in the sarcolemma. these are not ion channels. act as … When voltage disturbance comes along, the protein changes shape and pushes on ion channels that are embedded in the sarcolemma

A

voltage-sensitive tubule proteins;

molecular levers

58
Q

voltage-sensitive tubule proteins:
terminal cisterna of SR have … sensitive calcium channels, and the voltage sensitive levers push on these and … them, pushing them open

A

pressure;

deform

59
Q

voltage-sensitive tubule proteins:
calcium rapidly floods out of SR and into the cytoplasm of the cell –> all the action will then occur at level of … - rapid diffusion of calcium throughout the sarcomeres

A

sarcomere

60
Q

voltage-sensitive tubule proteins: calcium ions will bind to …, facilitating movement of tropomyosin to expose active sites such that the myosin heads on the thick filaments can bind to binding sites on the actin filaments, creating a …

A

troponin;

cross-bridge

61
Q

cross-bridge: physical joining of … in thick filament ot … on filamentous actin

A

myosin head; myosin binding site

62
Q

when not contracting, intracellular calcium concs are

A

low

63
Q

… and … pop off when myosin binds so that it can change shape and pull thin filaments towards M line

A

ADP; Pi

64
Q

regeneration via creatine phosphate - direct phosphorylation
facilitated by …, which sticks as phosphate onto creatine

A

creatine kinase

65
Q

muscles store creatine phosphate:
the amount that muscles hold can be increased - through …, will be absorbed into muscles
but total amount that can be absorbed gives at most … of ATP

A

supplements; 4-6 s

66
Q

increased … leads to increased “muscle size” - it’s not more muscle …, it’s increased … tissue

A

vasculature; tissue; circulatory

67
Q

exercise strengthens …, training muscles to have more … per contraction as compared to prior to working out

A

neuromuscular junctions;

cross bridge cycles

68
Q

forming cross bridge cycles with at best 40% of available myosin heads in thick filaments - this is because tends have to grow as well when muscles do, and tendons gain strength at … the speed of muscles, so if 100% of myosin heads were used, you’d increase the risk of …

A

1/8th;

tearing tendons

69
Q

steroids allow for muscles to … more quickly, doesn’t cause muscles to … more quickly

A

recover; strengthen

70
Q

at …, ATP has been burned through and ATP supply depends on glycolysis leading to lactic acid buildup

A

70% of maximum contractile activity

71
Q

smaller changes in muscle size primarily due to increased …, but over years, actual … amounts can be increased

A

vasculature; muscle fiber

72
Q

net gain of … ATP/glucose through aerobic respiration

A

32

73
Q

muscle fatigue occurs due to ionic imbalances (caused partly by …) - contraction becomes …, start getting … and … - not getting full … at end plate

A
sweating; 
jittery; 
spasms; 
cramps; 
action potential
74
Q

total lack of ATP rarely occurs - only when you’re … –> …, this state only ends when muscle begins to degrade

A

dead; rigor mortis

75
Q

…% of energy investment is lost as heat - inefficient process
… allows for heat dissipation

A

60; sweating;