問題一覧
1
which of these is not one of theee major types of skeletal muscle fibre
resistant
2
? produced by an i social muscle fibre, or indeed an entire skeletal muscle, can vary widely and can change moment to moment
tension
3
? ions are released into the sarcoplasm on receiving electrical signals
calcium (Ca2+)
4
a motor unit containing few muscle fibres produces
fine movement
5
interactions during contraction produce ? and consume energy
tension
6
a single stimulus contraction relaxation sequence in a muscle fibre is called a twitch, which can be measured as a
myogram
7
each cell in skeletal muscle tissue is a
single muscle fibre
8
what functions of skeletal muscle is least dependent on its connections to other tissues
heat generation
9
which organs are capable of generating heat
skeletal muscle only
10
? is induced in muscle when the stimulation rate is increased so much that the relaxation phase is completely eliminated
complete tetanus
11
muscle tissue, one of the four principle types of tissue, consists chiefly of muscle cells that are highly specialised for
contraction
12
what is the role of Ca2+ in the muscle action potential?
none - Ca2+ only regulates contraction
13
when a whole motor nerve is stimulated electrically, increasing strength of stimulus causes the muscle to contract more strongly. why is the all or non law apparently not obeyed
a motor nerve contains many motor units. greater stimulation causes additional motor units to become active
14
at the molecular level, the energy source for contraction is
ATP
15
when a skeletal muscle contracts
the width of the A band remains constant
16
what is generally considered in terms of power and endurance
muscle performance
17
which of the following can not be used to describe part of a single twitch
tetanic phase
18
during excitation contraction coupling, troponin bonds Ca2+. how does this enable contraction to occur
troponin causes tropmyosin to expose the myosin binding site on the Acton filament
19
after release from the sarcoplasmic reticulum, ions then trigger interactions between ? resulting in muscle fibre contraction
thick and thin filaments
20
while Ca2+ is present in the sarcoplasmix reticulum
the muscle will continue to contract
21
which muscle type does not contract spontaneously
skeletal muscle
22
what is the role of the sarcoplasmic reticulum in skeletal muscle
store Ca2+ and release it when triggered by an action potential
23
if a second stimulus arrives before the relaxation phase has ended a second more powerful contraction occurs which is referred to as
wave summation
24
a strand of the protein ? lies alongside thin filaments, which helps align thin filaments of the sarcomere
nebulin
25
elextrical implieses (action potential) travel down ? into the muscle cells to efficiently trigger muscle fiver contraction
transverse tubules
26
how many subunits does troponin molecule have
3
27
during contraction, thin filaments slide towards the centre of each sarcomere alongside the thick filaments and sliding occurs in every sarcomere along a myofibril, thus the
myofibril gets shorter
28
a muscle fibre is either contracting or relaxed, this is the ? and whje a fibre contracts it does so fully
all or non principle
29
what is the first step in the contraction of a skeletal muscle fibre
an action potential is triggered at the neuromuscular junction
30
the first step in muscle contraction is the release of ? into the sarcoplasm
calcium ions
31
myofilaments are organised into repeating functional units called ?
sarcomeres
32
the energy dependent rotation of the myosin head during muscle contraction is responsible for
pusing the actin filament
33
skeletal muscle tissue forms skeletal muscles, organs that also contain each of the following except
bones
34
in the ? thin filaments are situated between the thick filaments and they can slide across each other during contraction
zone of overlap
35
what is the name for the cylindrical structures which can actively shorten and this are responsible for skeletal muscle fibre contraction
myofibrils
36
a sarcomere contains each of the following except
proteins that regulate generation of thick and thin filaments
37
the ? is an intracellular membrane complex, containing Ca2+ ions
sarcoplasmix reticulum
38
which of the following correctly describes the sarcomere during contraction
A band constant, I band gets smaller, Z lines I’ve closer together
39
accumulation of lactic acid in contracting skeletal muscle is also called the ‘oxygen debt’. what does this mean
lactic acid is a waste product of oxygen I depend glucose metabolism. it is converged back into glucose during recovery, consuming oxygen
40
visually, when viewed microscopically, the sarcomeres have a banding pattern of A bands with a ? at the centre
M line
41
skeletal muscles perform each of the following functions excepr
moves contents of the digestive tract
42
what is the role of T tubules in skeletal muscle function
ensure the muscle is exxited as quickly and evenly as possible
43
the model representing the physical changes that occur, which describes what happens to the sarcomere during contraction is called the
sliding filament theory
44
myofibrils consist of bundles of ? which are protein filaments composed primarily of thin filaments and thick filaments
myofilaments
45
what is another name for the cell membrane of a muscle fibre
sarcolemma
46
normal skeletal muscle contraction only occurs when skeletal muscle fibres are activated by motor neurons resulting in so called
excitation-contraction coupling
47
curare completely blocks cholinergic transmission at the neuromuscular junction. it will therefore cause
complete paralysis and relaxation
48
strands of the protein ? function to keep the thick and thin filaments in proper alignment, helps resist extreme stretching, and returns stretched muscles to resting length
titin
49
during development, groups of ? fuse together to form individual skeletal muscle fibres
myoblasts
50
which of the following is not a type of muscle tissue
vascular
51
during peak activity muscles cannot generate enough ATP from oxygen dependent metabolism. what happens?
energy is derived from oxygen independent mechanisms
52
if a muscle is stretched until the zone of overlap disappears
it can no longer contract
53
if a skeletal muscle is stimulated a second time immediately after the relaxation phase has ended the force will rise, if this happens repeatedly force rises like steps in a staircase, a phenomenon called
treppe
54
when sarcomere shorten in a contraction, they ? the muscle fibre
shorten
55
which strands are part of the thin filament and function to cover active sites thus preventing actin-myosin interactions
tropomyosin
56
under resting conditions, interaction between thick and thin filaments and this muscle fibre contraction is prevented by the ? complex
troponin- tropomyosin
57
what component of sarcomere does the I band represent
the portion of thin filaments not overlapping with thick filaments
58
muscle fibre contraction involves the interaction of ? of the thick filaments with binding sites on the thin filaments
myosin heads