L11: Skeletal Muscle Organ, Structure and Function Flashcards Preview

ANAT > L11: Skeletal Muscle Organ, Structure and Function > Flashcards

Flashcards in L11: Skeletal Muscle Organ, Structure and Function Deck (57):
1

what are the three types of muscles?

- cardiac
- skeletal
- smooth

2

what makes up skeletal muscle tissue?

- muscle cells
- extracellular matrix (minimal)

3

muscle cell/fibre are/consist of?

- multinucleated
- myofibrils

4

what are myofibrils?

- bundles of myofilaments

5

what are myofilaments?

- actin and myosin contractile proteins

6

classification of type 1 skeletal muscle cells

- slow oxidative
- slow aerobic

7

size of type 1 skeletal muscle cells

smallest

8

function and power of type 1 skeletal muscle cells

- fatigue resistant
- least powerful

9

classification of type 2a skeletal muscle cells

- fast oxidative
- fast aerobic

10

size of type 2a skeletal muscle cells

- intermediate

11

fatigue resistance of type 2a skeletal muscle cells?

- some fatigue resistance

12

classification of type 2b skeletal muscle cells

- fast glycolytic
- fast anaerobic

13

size of type 2b skeletal muscle cells

- largest

14

Properties of type 2b skeletal muscle cells

-fatigue
- most powerful
- most common

15

each muscle contains a combination of the fibre types
TRUE or FALSE?

-true
- %s vary according to function

16

how many tissues present in skeletal muscle organs?

- 4 tissues

17

what is a myotendinous junction?

- collagen fibrils of the tendon attach to the end of the muscle fibres

18

what is ethesis?

- where a tendon or ligament attaches to bone

19

what do collagen fibrils attach to?

- periosteum and/or anchor into the bone tissue

20

what is a motor unit?

a single motor neuron and the muscle fibres it innervates

21

what is an isometric contraction?

- muscle force matches load
- constant length

22

what are isotonic contractions?

-concentric
- eccentric

23

what is a concentric contraction?

- muscle force >load
- muscle shortens
-e.g lifting weight

24

eccentric contraction?

- muscle force

25

what is isokinetic?

constant speed

26

what are sphincters

- fibres arranged concentrically around an opening
- circular

27

example of sphincters?

- orbicularis oris
- orbicularis oculi

28

what is parallel muscle architecture

- fascicles parallel to muscle

29

example of fascicles parallel to muscle

- masseter
- biceps brachii
- rectus abdominis
- sartorius

30

what is convergent muscle architecture?

- fibres converge toward a common attachment site

31

example of convergent muscles?

- pectoralis major
- latissimus dorsi

32

what is pennate (feather) muscle architecture?

- fascicles at an oblique angle to the tendon

33

what are the three different types of pennate muscles

- unipennate
- bipennate
- multipennate

34

the extensor digitorum is what sort of pennate muscle?

unipennate

35

the arrangement of fascicles in the rectus femoris is?

- bipennate

36

the arrangement of fascicles in the deltoid is ?

multipennate

37

function of parallel muscles

excursion

38

function of pennate muscles

strength

39

function of axial muscles

- stabilise or move elements of axial body

40

function of appendicular muscles

- stabilise or move appendicular body

41

3 compartments of the thigh?

- anterior
- posterior
- medial

42

3 compartments of the leg?

- anterior
- posterior
- lateral

43

what must a muscle cross in order to actively move a joint

- cross a joint

44

what determines which movements are available?

joint structural and functional classification

45

what helps predict a muscles general action relative to the joint it crosses

- the location of a muscle

46

the amount of force that a muscle produces is a function of its?

physiological cross sectional area (PCSA)

47

what is line of action?

when a muscle contracts concentrically it will pull its attachment site toward the centre of the muscle belly

48

for a given force, the resultant moment will be affected by its?

- moment arm

49

in biomechanics, bones are considered

levers

50

in biomechanics, joints are considered

axes/ centre of rotation (COR)

51

in biomechanics, muscles provide ?

force = pull

52

what is moment of force?

- strength of rotation of body segment
-produced by force

53

what is moment arm?

- perpendicular distance from the COR to the line of action of the force

54

a force directed through the centre of rotation will produce a?

translation

55

a force applied at a distance from the centre of rotation will produce a??

rotation called moment of force

56

when a force acts on an object, and the object is fixed at some point, the object will?

- rotate around the fixed point
- results in a rotation called moment of force

57

when a force (muscle pull) acts on an object (bone), and the object is fixed at some point (joint), the object will??

- rotate around the fixed point