Ch. 10 - Anatomy of the Muscular System Flashcards
The body contains more than _____ skeletal muscles
600
skeletal muscle is ____ % to ____% of body weight
40 - 50
Muscles, along with the skeleton, determine the ________ and ___________ of the body
form and contour
Skeletal muscles vary considerably in the following 3 things:
- size
- shape
- fiber arrangement
size of muscle ranges from:
extremely small to large masses
11 muscle shapes
broad, narrow, long, tapering, short, blunt, triangular, quadrilateral, irregular, flat sheets, or bulky masses
6 types of muscle arrangement
- parallel
- convergent
- pennate
- fusiform
- spiral
- circular
the direction of muscular fibers is significant because of its relation to __________
function
2 points of muscular attachment
Origin
Insertion
attachment of muscle that is “point of attachment that does not move when the muscle contracts”
origin
attachment of muscle that is “point of attachment that moves when the muscle contracts”
insertion
Most movements are produced by the ___________ action of several muscles; some muscles in the group _________ while others _________
coordinated
contract
relax
a muscle that directly performs a specific movement
Prime mover
any “mover” muscle that directly performs a movement, including the prime mover
Agonists
muscles that, when contracting, directly oppose prime movers; relax while the prime mover (agonist) is contracting to produce movement; provide precision and control during contraction of prime movers
Antagonist
muscles that contract at the same time as the prime movers; facilitate prime mover actions to produce a more efficient movement
Synergists
joint stabilizers (type of synergist)
Fixator muscles
Muscle names can be in ________ or _________
latin
english
5 ways muscles are named
- Location, function, shape
- Direction of fibers
- Number of heads or divisions
- Points of attachment
- Relative size
4 Rotator cuff muscles
- Infraspinatus
- Supraspinatus
- Teres minor
- Subscapularis
Quadriceps femoris group:
Rectus femoris
Vastus medialis
Vastus lateralis
Vastus intermedius
3 muscles in the gluteus
- gluteus maximus
- gluteus minimus
- gluteus medius
2 injection sites
Deltoid
Gluteus medius
this muscle raises or lowers the shoulder
Trapezius
flat sheet of connective tissue connecting muscle to oterh structures
Aponeurosis
this muscle assists with mastication
Masseter
posterior arm muscle that extends the forearm
Triceps brachii