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Flashcards in Muscles I Deck (36)
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1
Q

Two types of regulatory proteins

A

Tropomyosin and troponin

2
Q

The fibre pennation angle of pennate muscles allow for …..

A

Packing of large numbers of fibres into smaller cross-sectional area

3
Q

Pennate fibres lie at _______ pennation angle

A

Oblique

4
Q

Pennation allows muscle fibres to be ______ relative to length of muscle

A

short

5
Q

Pennate muscles differ from fusiform muscles in that they contain (longer/shorter) fibres, possess (more/less) individual fibres, and exhibit (more/less) range of motion

A

Shorter fibres, more individual fibres, and less range of motion

6
Q

Perimysium surrounds?

A

A bundle of fibres called a fasciculus

7
Q

Differences in sarcomere_________ and ______ affect muscle’s force and power generating capacity

A

alignment and length

8
Q

Fusiform fibres run ______ to muscles long axis and _____ at tendinous attachment

A

parallel; taper

9
Q

Effect of training on muscle capiliaries

A

Increased capillary-to-muscle fibre ratio, enhanced capillary microcirculation

10
Q

Cross-bridge cycling depends on ____ _______

A

ATP hydrolysis

11
Q

______ actin filaments encircle each myosin filaments

A

Six

12
Q

Two types of contractile proteins

A

Myosin and actin

13
Q

Muscle functions (4)

A

Producing body movement, stabilizing body positions, storing and moving substances within the body, generating heat

14
Q

Contents of myofibrils

A

Myofilaments

15
Q

Low energy form of myosin head

A

ATP bound to myosin; low affinity for actin

16
Q

What stimulates capillary development during training?

A

Vascular stretch/shear stress on vessel walls from increased blood flow

17
Q

Contents of muscle fibre

A

Myofibrils

18
Q

Muscle properties (3)

A

Excitable, contractable, extensible

19
Q

Sarcoplasmic reticulum provides

A

Structural integrity

20
Q

Sarcolemma surrounds…

A

Each muscle fibre and encloses a fibre’s cellular contents

21
Q

Three types of muscle proteins

A
  1. Contractile
  2. Regulatory
  3. Structural
22
Q

___________: shortening of muscles; how muscles generate force

A

Cross-bridge cycle

23
Q

________ muscles facilitate rapid muscle shortening because fibre length = muscle length

A

Fusiform

24
Q

High energy form of myosin head

A

ADP and Pi bound; high affinity for actin

25
Q

________ filaments have two twisted monomer chains bound by tropomyosin polypeptide chains

A

Actin

26
Q

________________: how muscle contractions are turned on and off

A

Excitation-contraction coupling

27
Q

Purpose of structural proteins

A

Contribute to the alignment, stability, extensibility, and elasticity

28
Q

Five types of structural proteins

A
  1. titin
  2. alpha-actinin
  3. myomesin
  4. nebulin
  5. dystrophin
29
Q

Two main mechanisms of force generation in muscle

A
  1. crossbridge cycle

2. excitation-contraction coupling

30
Q

Pennate muscles generate _______ power

A

Considerable

31
Q

Endomysium surrounds…?

A

Each muscle fibre to separate it from neighbouring fibres

32
Q

Degree of pennation directly impacts….

A

Sarcomere fibre number per cross-section of muscle

33
Q

Epimysium surrounds…?

A

Entire muscle and blends into intramuscular tissue sheaths to form tendons

34
Q

_________ filaments are bundles of molecules with polypeptide tails and globular heads

A

Myosin

35
Q

Myofilaments consist of:

A

Actin and myosin

36
Q

Four major steps of contraction cycle

A
  1. ATP hydrolysis
  2. Attachment of myosin to actin
  3. Power stroke
  4. Detachment of myosin from actin