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A2 BIOLOGY (PAPER 2) > Skeletal Muscle > Flashcards

Flashcards in Skeletal Muscle Deck (19):
1

What are the three types of muscle give any alternative names

Skeletal/striated/ voluntary
Cardiac
Smooth/ involuntary

2

Where does skeletal muscle occur?

At skeletal joints

3

What is meant by the term antagonistic pairs?

One muscle must reflax for another to contract

4

Thin filaments are also known as?

Actin

5

Thick filaments are also known as?

Myosin

6

What causes striation on skeletal muscle?

The arrangement of myosin and actin fibres

7

Describe cardiac muscle

Branched to ensure charge distribution
Contain intercolated disks
Striated
Myogenic

8

Describe smooth muscle

Slow to contract and slow to tire
Less striated
Two layers of smooth muscle

9

Describe what happens at a neuromuscular junction

Action potential travels down the Motor neurone
Volatge gated Ca2+ channels open
Causes vesicles of acetylcholine to fuse to membrane
Acetylcholine diffuses out binds to receptors
Na+ channels open causes depolarisation
Wave of depolarisation travels down the T tubule to the sacrolemma

10

When a motor neurone branches and controls more than one muscle what is this called?

Motor unit

11

Describe slow twitch muscle and the conditions it requires

Slow contractions
Less powerful but over a greater period of time
Requires aerobic respiration and therefore rich blood vessel supply and many mitochondria

12

Describe fast twich muscle and the condions it works in

More quick
More powerful but cant go for long periods pf time
Intense excerises
Usually anerobic respiration
So needs many enzymes
Glycogen
And phosphocreatine

13

What two filaments are present in a myofibril

Myosin and actin

14

The myosin head can bind to?

Actin

15

Describe the interrelationships between tropomyosin tropanin and actin

Tropomyosin hides actin binding sites. It also binds to tropnin
Troponin has binding sites if Ca2+ binds it changes shape
Uncovers the actin site by moving tropomyosin in this shape change

16

An action potential has arisen down t tubules, describe how this triggers a muscular response

Action potential reaches sarcoplasmic reticulum
Releases Ca2+ into the sarcoplasm
Ca2+ reaches troponin binding sites
Allows myosin and actin to bind
Allows sliding filament hypothesis

17

Describe the sliding filament hypothesis

ATP attaches to myosin head
ATP----> ADP + Pi
Moves myosin head back storing elastic potential energy
Myosin attches to actin sites
Power stroke occurs where myosin head snaps forward
ATP inputted causing myosin to detach
Shortens the sacromere

18

How are muscle contractions stopped?

Ca2+ ions are actively transported back into the sacroplasmic reticulum

19

Other than aerobic and traditional anaerobic respiration describe how energy for muscle contraction can occur

Creatine phosphate
Phosphate removed
Added to ADP
ATP formed