Exam 2 - Lecture Notes

Question 1

(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

Answer 1

even;
joint;
straight

Question 2

(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

Answer 2

spirals

Question 3

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

Answer 3

quickly; forcefully

Question 4

(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

Answer 4

GI tract; bladder; airways; lungs

Question 5

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

Answer 5

muscles

Question 6

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 ..

Answer 6

skin cell; wide; long

Question 7

(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

Answer 7

excited;

extensibility

Question 8

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

Answer 8

body position

Question 9

muscle stabilizes joints and … system

most complex joint system is that of the …

Answer 9

skeletal;

knee

Question 10

muscles allow for heat generation via shivering:

only source of generating … for humans

Answer 10

additional heat

Question 11

“white” pieces around muscle is mostly

Answer 11

protein

Question 12

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

Answer 12

end of the bone

Question 13

fingers are entirely … - no …

Answer 13

tendons; muscle

Question 14

there are muscles in palms

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

Answer 14

indirect tendons up through to fingers;

moving fingers

Question 15

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

Answer 15

blood vessels; nerve fibers; connective tissue

Question 16

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

Answer 16

skinny

Question 17

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

Answer 17

fusing together

Question 18

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

Answer 18

tertiary structure; quaternary structure

Question 19

sarcoplasmic reticulum is not concerned with …; there as storage

Answer 19

protein construction

Question 20

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

Answer 20

cytoskeletal

Question 21

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

Answer 21

thick, stiff ropelike

Question 22

myofibril:

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

Answer 22

thin

Question 23

myomesin makes up M line in sarcomere:

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

Answer 23

holds thick filaments in place

Question 24

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

Answer 24

thick filament; thick filament

Question 25

thick filaments anchored to Z disc by protein called ... --> acts like a ...

Answer 25

titin; spring

Question 26

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

Answer 26

titin; | elasticity

Question 27

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

Answer 27

A band; I band

Question 28

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

Answer 28

tails; myosin head; motor protein

Question 29

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 ...

Answer 29

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

Question 30

actin is a polymer: | if it is not polymerized it is called ... 0 ...

Answer 30

G actin; globular actin

Question 31

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 ...

Answer 31

polymerizes; tropomyosin; troponin

Question 32

(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 - ...

Answer 32

spiral; | complementary spiral nature; reinforcer

Question 33

(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

Answer 33

conformational change; | pitch;

Question 34

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

Answer 34

embedded ribosomes; | webbing

Question 35

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+

Answer 35

T tubules; | voltage-gated receptors

Question 36

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

Answer 36

invaginations; | coordinated

Question 37

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

Answer 37

jerky; smooth; even

Question 38

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

Answer 38

terminal cisternae; T tubule; SR

Question 39

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

Answer 39

shape; foot

Question 40

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

Answer 40

calcium channels; | cytoplasm

Question 41

... 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

Answer 41

isometric; thin filaments

Question 42

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

Answer 42

overlapping; myosin

Question 43

... shorten when contraction, but ... do not change length

Answer 43

sarcomeres; filaments

Question 44

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

Answer 44

thick and thin filaments; H line; actin

Question 45

...: bundle of axons in PNS

Answer 45

nerve

Question 46

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

Answer 46

unevenly; muscle tears

Question 47

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

Answer 47

postsynaptic endplate

Question 48

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 - ...

Answer 48

reabsorbed; acetylcholinesterase

Question 49

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

Answer 49

longer; | refractory period

Question 50

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

Answer 50

synaptic vesicles

Question 51

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)

Answer 51

docked; | SNAREs

Question 52

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

Answer 52

calcium leak channels

Question 53

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

Answer 53

diffuses instantly

Question 54

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

Answer 54

excitation-contraction coupling; | latent periods

Question 55

... channels spread evenly throughout sarcolemma

Answer 55

voltage sensitive sodium

Question 56

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

Answer 56

lengthwise; circumference

Question 57

... 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

Answer 57

voltage-sensitive tubule proteins; | molecular levers

Question 58

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

Answer 58

pressure; | deform

Question 59

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

Answer 59

sarcomere

Question 60

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 ...

Answer 60

troponin; | cross-bridge

Question 61

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

Answer 61

myosin head; myosin binding site

Question 62

when not contracting, intracellular calcium concs are

Answer 62

low

Question 63

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

Answer 63

ADP; Pi

Question 64

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

Answer 64

creatine kinase

Question 65

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

Answer 65

supplements; 4-6 s

Question 66

increased ... leads to increased "muscle size" - it's not more muscle ..., it's increased ... tissue

Answer 66

vasculature; tissue; circulatory

Question 67

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

Answer 67

neuromuscular junctions; | cross bridge cycles

Question 68

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 ...

Answer 68

1/8th; | tearing tendons

Question 69

steroids allow for muscles to ... more quickly, doesn't cause muscles to ... more quickly

Answer 69

recover; strengthen

Question 70

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

Answer 70

70% of maximum contractile activity

Question 71

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

Answer 71

vasculature; muscle fiber

Question 72

net gain of ... ATP/glucose through aerobic respiration

Answer 72

32

Question 73

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

Answer 73

``` sweating; jittery; spasms; cramps; action potential ```

Question 74

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

Answer 74

dead; rigor mortis

Question 75

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

Answer 75

60; sweating;