Wk 3: myology

Question 1

Muscle characteristics

Answer 1

Excitability
Contractibility
Elasticity
Extensibility

Question 2

Excitability (muscle characteristics)

Answer 2

tissue responds to a stimulus

Question 3

Contractility (muscle characteristics)

Answer 3

tissue can shorten & generate force

Question 4

Extensibility (muscle characteristics)

Answer 4

tissue can be stretched

Question 5

Elasticity (muscle characteristics)

Answer 5

tissue can return to original length

Question 6

Muscle types

Answer 6

• Smooth: non-striated and involuntary
• Cardiac: striated and involuntary
• Skeletal: striated and voluntary

Question 7

Gross anatomy of skeletal muscle

Answer 7

• Belly: the bulk of the muscle
• Attachments: to the skeleton
• Muscles CROSS joints

Question 8

Types of attatchments

Answer 8

• Proximal attachment (origin usually): least mobile bone
• Distal attachment (insertion usually): most mobile bone

Question 9

Tendon Sheaths

Answer 9

• Surround tendons as they pass through tunnels or over other structures
• Reduce friction (contain synovial fluid)
• Common at distal ends of limbs
• Allow efficient ‘action’ long distances from muscle belly: prevent tendons pulling away from skeleton

Question 10

Skeletal muscle attachments

Answer 10

Fleshy

Tendon

Raphe

Question 11

Fleshy (muscle attatchment)

Answer 11

muscle fibres attach directly to bone with a small amount of connective tissue

Question 12

Tendon (muscle attachment)

Answer 12

muscle fibres attach to a cord of connective tissue that attaches to bone

fibre-> connective tissue -> bone

Question 13

Raphe (muscle attachment)

Answer 13

muscle fibres attach to a sheet of connective tissue that attaches to bone

fibres-> sheet of connective -> bone

Question 14

Parallel skeletal muscle types

Answer 14

Strap
Fusiform
Triangular/convergent
Flat/quadrilateral

Question 15

Strap

Answer 15

long and flat

Question 16

Fusiform

Answer 16

classic type

Question 17

Triangular/convergent

Answer 17

broad origin and narrow insertion

Question 18

Flat/quadrilateral

Answer 18

fibres in same axes as tendon

Question 19

Oblique skeletal muscle types

Answer 19

Unipennate

Bipennate

Multipennate

Question 20

Unipennate

Answer 20

muscle fibres attach to one side of tendon only

Question 21

Bipennate

Answer 21

fibres attach to both sides of tendon and central septum

Question 22

Multipennate

Answer 22

group of several bipennate ‘units’

Question 23

Sliding filament theory:

Answer 23

• Actin (thin) & myosin (thick) filaments slide over one another
• Produce muscle shortening

Question 24

Parallel muscles

Answer 24

maximum shortening of muscle belly

• Larger range of movement but with less force/power

Question 25

Oblique muscles

Answer 25

**less shortening **of muscle belly * Less range of movement BUT more **force/power**

Question 26

Muscle action what to describe

Answer 26

what JOINT is MOVED name of MOVEMENT

Question 27

Functional anatomy

Answer 27

is taking the knowledge of the body structures that we learn and applying it to live, moving bodies

Question 28

Action

Answer 28

the movement produced when a muscle contracts concentrically in isolation

Question 29

Action is dependant on

Answer 29

* Site of attachments * Type of joint * Relationship of line of pull to joint

Question 30

Isometric contraction

Answer 30

* Occurs when tension is generated in a muscle * Muscle length and angle of joint DOES NOT change * Produces no movement

Question 31

Isotonic contraction

Answer 31

* Muscle contraction that **changes** the length Eccentric and concentric

Question 32

Eccentric

Answer 32

muscle lengthening

Question 33

Cocentric

Answer 33

muscle shortening

Question 34

Functions/roles of skeletal muscles

Answer 34

* Agonist * Antagonist * Fixator (stabiliser) * Synergist (neutraliser)

Question 35

Agonist

Answer 35

muscle producing the desired movement by contracting * Concentric, eccentric or isometric

Question 36

Antagonist

Answer 36

muscle which must relax to allow the desired movement to occur * Usually the opposite muscle to the agonist Cannot have another role

Question 37

Fixator/stabiliser

Answer 37

stabilises a body segment so that another muscle can perform an action * Acts to eliminate the unwanted movement of an agonist's origin

Question 38

Synergist/neutraliser

Answer 38

assists the agonist to produce the desired movement by cancelling the unwanted action of the agonist

Question 39

External forces

Answer 39

Gravity: force acting on every object Momentum: can produce movement

Question 40

Two joint muscles

Answer 40

passes over two joints * Implications for recruitment: increased requirement for synergism * Implications for joint range testing: must consider 2 joint muscles when testing range of motion

Question 41

Length-Tension relationship

Answer 41

direct relationship between the tension a muscle fibre can produce and the length of the sarcomeres in that muscle fibre

Question 42

Passive insufficiency

Answer 42

max passive length is insufficient to allow full range of movement at both joints together

Question 43

Active insufficiency

Answer 43

max length change insufficient to produce full range of movement at both joints together

Question 44

Axis/fulcrum

Answer 44

pivot point

Question 45

Force/load

Answer 45

external force (gravity/weight, friction)

Question 46

Resistance/effort

Answer 46

generated by the muscle pulling

Question 47

Types of levers

Answer 47

ARF