Muscle contraction

?
  • Created by: syaqub18
  • Created on: 08-05-15 16:52
What are the three types of muscle fibres?
Smooth muscle, cardiac muscle and skeletal muscle
1 of 31
What is smooth muscle?
Muscles which contract without conscious control such as stomach, intestines and blood vessels
2 of 31
What is a cardiac muscle?
Muscles which contract without conscious control but only found in heart
3 of 31
What is skeletal muscle made up of?
Large bundles of long cells called muscle fibres
4 of 31
What is the cell membrane of a muscle fibre called?
The sarcolemma
5 of 31
What is the cytoplasm of a muscle fribre called?
Sarcoplasm
6 of 31
What are the fold in the sarcolemma called?
T-tubules (transverse tubules)
7 of 31
What is the purpose of t-tubules?
To spread electrical impulse throughout the sarcoplasm so they reach all parts of muscle fibre
8 of 31
What are the networks of internal membranes called?
Sarcoplasmic reticulum
9 of 31
What is the job of the sarcoplasmic reticulum?
Stores calcium ions for muscle contraction
10 of 31
What is the meaning of multinucleate?
Having many nuclei
11 of 31
What are the long cylindrical organelles in the muscle called?
Myofibrils
12 of 31
what is the purpose of myofibrils?
They contain thin and thick myofilaments that move past each other to cause a contraction
13 of 31
What are the thick myofilaments in myofibrils made up of?
Myosin
14 of 31
What are the thin myofilaments made up of?
Actin
15 of 31
Under a microscope, which band appears dark?
A-band
16 of 31
What does the A-band contain?
Myosin filaments which some overlapping actin filaments
17 of 31
Under a microscope, what band appears light?
I-band
18 of 31
What does the I-band contain?
Actin filaments
19 of 31
What are the short units of a myofibril called?
Sacromere
20 of 31
What marks the end of each sarcomere?
The Z-line
21 of 31
What is the middle of each sarcomere?
The M-line
22 of 31
What does the H-zone consist of?
Only of myosin filaments
23 of 31
What is the sliding filament theory?
Myosin and actin filaments slide over each other to make sarcomere contract, myofibrils themselves do not contract
24 of 31
What happens do the bands when sacromeres contract?
A-band stays the same, I-band gets shorter, H-zone gets shorter
25 of 31
what are the stages of muscle contraction?
Arrival of an action potential, movement of the actin filament, breaking of cross bridge, return to resting state
26 of 31
What happens in the arrival of an action potential stage of muscle contraction?
Action potential depolarises sarcolemma, moves down t-tubules to sarcoplasmic reticulum, releases Ca2+ ions, ions bind to troponin to change its shape, this pulls out tropomyosin, actin-myosin cross bridge formed
27 of 31
What happens in the movement of the actin filament stage of muscle contraction?
Ca2+ ions also activate ATPase to break down ATP for energy for muscle contraction, energy allows myosin globular head to preform power stroke
28 of 31
What happens in the breaking of cross bridge stage of muscle contraction?
ATP provides energy to break cross bridge, myosin head removed from binding site and returns to starting position and reattaches to another binding site, cycle repeated.
29 of 31
What happens in the return to resting state stage of muscle contraction?
When stimulation stops, Ca2+ ions leave their troponin binding site and go back to sarcoplasmic reticulum (needs ATP), troponin goes back to normal shape, tropomyosin blocks actin-myosin binding site
30 of 31
How do the muscles get energy from ATP-phosphocreatine system (PCr)?
PCr joins to ADP to make ATP, PCr stored in cells, PCr system is very quick, PCr runs out very quick
31 of 31

Other cards in this set

Card 2

Front

What is smooth muscle?

Back

Muscles which contract without conscious control such as stomach, intestines and blood vessels

Card 3

Front

What is a cardiac muscle?

Back

Preview of the front of card 3

Card 4

Front

What is skeletal muscle made up of?

Back

Preview of the front of card 4

Card 5

Front

What is the cell membrane of a muscle fibre called?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Cellular processes and structure resources »