Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIOE340 > skeletal muscle contraction (midterm 1) - look at figures as well > Flashcards

skeletal muscle contraction (midterm 1) - look at figures as well Flashcards

1
Q

what are satellite cells

A

resident progenitor cells which matures into either another satellite cell or a myoblast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is a myoblast

A

mononucleated cells that fuse to form myotubes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are myotubes (myofibrils)

A

multinucleated, function cell of skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are myofibers

A

organized structures of myotubes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what happens to satellite cells during skeletal muscle regeneration

A

they become activated and proliferate -> they can repopulate the reserve or differentiate into myoblasts (absolute number of satellite cells decreases with age)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

in the muscle, how are myofibers organized

A

they’re stacked and bound by connective tissues that contain nerves and blood vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are skeletal muscles composed of

A

muscle cells, connective tissue, blood vessels, and nerve fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the primary functions of skeletal muscle

A

contraction, force generation, and induction of movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the parenchymal cell

A

muscle fiber responsible for muscle contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is muscle fiber composed of

A

(10-80 um diameter) sarcolemma -> membrane: muscle -> tendon -> bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are myofibrils composed of

A

sarcomere: actin and myosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is an A-band

A

anisotropic (polarized light) => dark -> areas with both myosin and actin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is an I-band

A

isotropic => light -> areas with just actin that helps identify a z-disk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what does a skeletal muscle look like

A

PICTURE IN NOTES PG 5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the sarcolemma

A

cell membrane of the muscle fiber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the ends of actin filaments attached to

A

a Z disc, which interdigitates with the myosin filaments

17
Q

what is a sarcomere

A

the portion of the myofibril that lies between two successive z discs -> normally 2 um when fully stretched resting length

18
Q

what is titin

A

maintains the side-by-side relationship between the myosin and actin filaments

19
Q

what is sarcoplasm

A

intracellular fluid the spaces between the myofibrils are filled with

20
Q

what is myosin molecules composed of

A

two heavy chains (make up myosin tail) and four light chains (make up myosin head)

21
Q

what are actin filaments composed of

A

actin, tropomyosin, and troponin
- composed of polymerized G-actin molecules, which each contain one ADP

22
Q

what are ASP molecules thought to be

A

active sites on which the cross-bridges of myosin filaments interact to cause muscle contraction

23
Q

what does it mean when z-bands are closer

A

more actin and myosin connection = more FORCE

24
Q

what are the three loosely bound protein subunits of troponin

A

troponin I = strong affinity for actin
troponin T = strong affinity for tropomyosin
troponin C = strong affinity for calcium ions

25
Q

what is the walk-along theory of contraction

A

after Ca++ activation, the heads of the cross-bridges from the myosin filaments become attracted to the active sites of the actin filament, and causes contraction to occur

26
Q

what is the energy source for contraction

A

ATP

27
Q

what determines tension in muscles

A

actin overlap - more overlap = more tension

28
Q

how long are sarcomeres

A

2.2 um - know the figures on slide 24 and 25

29
Q

what occurs with more fast fibers

A

faster muscles

30
Q

what provides 5-8 seconds of additional contraction

A

phosphocreatine

31
Q

what provides 60 seconds of contraction

A

glycogen

32
Q

what occurs with isometric contraction

A

muscle length does not change during contraction

33
Q

what occurs with isotonic contraction

A

muscle tension does not change during contraction

BIOE340 (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions