week 3 Flashcards
Parallel muscles fibre orientation
Larger range of movement BUT with less force/power
sliding filament theory.
actin (thin) & myosin (thick) filaments slide over one another
Oblique muscles
Less range of movement BUT more force/power
Strap
Long & flat parallel muscle
Fusiform
the classic shape of parallel muscle
Triangular/convergent
Broad origin & narrow insertion
Flat/quadrilateral
Fibres in same axis as tendon
Unipennate
Fibres attach to one side of tendon only
Bipennate
Fibres attach to both sides of
central septum & tendon
Multipennate
Group of several bipennate ‘units’
Muscle characteristics
- Excitability: Respond to a stimulus
- Contractility: Can shorten & generate force
- Extensibility: Can be stretched
- Elasticity: Can return to original length
Muscle types
- Smooth: Non-striated & Involuntary
- Cardiac: Striated ( verticle stripped) & Involuntary
- Skeletal: Striated & Voluntary
Muscle fibre/ cell is encased in tissue called
endomysium
collectrion of muscle fibres is called
Fascile
Entire muscle itself is encased in a tissue called
empimysium
fibre
Long cylindrical muscle cell / Multi-nucleated
Tendon sheaths
surround tendons as they pass through tunnels or over other structures to reduce friction and contain small amts of synovial foots. Common at distal ends of limbs
fleshy
Muscle fibres attach directly to bone with small amount of connective tissue
Eg deltoid
Tendon
Muscle fibres attach to a cord of connective tissue that then attaches to bone
Eg bicep
Raphe
Muscle fibres attach to a sheet of connective tissue that then attaches to bone
Eg abdoninal wall
Fibre direction when crossing a joint matters horizontal/ vertical
Horizontal or oblique fibres produce rotation movements
Vertical fibres produce angular movements
anterior movement/ action
movement- anteriorly directed
action- flexion
posterior movement/ action
movement posteriorly directed
action- extension
medial movement/ action
movement- medially directed
action- adduction
lateral movement/ action
movement- laterally directed
action- abduction
muscles in the same area can..
act on 2 or more joints
have same nerve supply
blood supply
lymphatic drainage
Action
what joint is moved and name of movement
Function
what is the use of the muscle in daily life
What is functional anatomy
Functional anatomy is taking the knowledge of the body structures that we learn and applying it to live, moving bodies.
isometric contraction
under tension the muscle length does not change
concentric contraction
muscle length shortens under tension
eccentric contraction
muscle length lengthens under tension
Agonist
Muscle producing the desired movement by contracting
Antagonist
Muscle which must relax (i.e. not contracting) to allow the desired movement to occur
stabiliser
Stabilises a body segment so that another muscle can perform an action
fixator/ synergist
is a stabiliser that acts to eliminate the unwanted movement of an agonist’s origin
neutraliser
Assists the agonist to produce the desired movement by cancelling the unwanted action of the agonist
other forces
- Gravity
- Sometimes momentum
Length-Tension relationship
Direct relationship between the tension a muscle fibre can produce and the length of the sarcomeres in that muscle fibre
Passive insufficiency
Maximum passive length is insufficient to allow full range of movement at both joints simultaneously best desc as a stretch
Active insufficiency:
Maximum length change insufficient to produce full range of movement at both joints simultaneously best desc as a cramp
first class lever
centeral axis w forces on one side and resistance on the other eg seesaw
second class lever
force on one end and the axis on the other end eg wheel barrow/ calf raise
resistance is in bw
third class lever
resistance on one end and axis on the other. the force is in between
eg bicep curl