Chapter 15 Flashcards
There are more than ____ skeletal muscles in the body
6000
From ____ to _____ of our body weight is skeletal muscles
40-50%
Muscles fill in the ___ and _____ of the body
Form and contour
Endomysium
Delicate CT membrane that covers skeletal muscle fibers
Muscle fibers=
Muscle cells
Perimysium are
Tough CT that binds groups of skeletal muscle fibres which are called fasicles (together)
Epimysium
Coarse sheath that covers the muscle as a whole
3 structures that fuse to become a tendon
Endomysium
Perimysium
Epimysium
The endomysium may extend as a
Flat, broad sheet of CT called an aponeurosis which typically merges wit hthe epimysuim of another
Tendons and aponeuroses are very ______ and often are not torn but _________
Strong
Pulled off bones
Most muscle span at least ______
One joint, attaching to the bone on either side
Origin of muscle
Point of attachement to the bone that remain fixed when movement at joint occurs
Insertion of muscle
Point of attachment to the bone that moves when a muscle contracts
Body of muscle
Main part of the muscle
Most body movements are produced dby the ______________
Coordinated action of groups of muscle. Somemuscles contract others relax
Types of main muscles involved in a movement (4)
Prime mover (agonist)
Synergist
Antagonist
Fixator
Primemover (agonist) main contraction is
Mainly responsible for producing a movement
A synergist contraction
Helps the prime mover produce a movement
The antagonist actions
Oppose the action of the prime mover in a movement
Fixator functions
As a joint stabilizer
In the upper arm the bicep is ___ the brachialis is ____ and the tricep is _____
Prime mover
Brachialis
Antagonist
Muscle movement resembles a _______ system
Lever and fulcrum
Bone are levers
Joints are falcrum
Movement is caused by
The ability of muscle cells to shorten of contract
Muscle cells are called
Fibers
All muscle fibers specialize in
Contraction (shortening)
Muscles are named according to whch 4 thinfs
- Location, function, shape, direction of fibers
- Number of heads or divisions
- Points of attachment
- Relative size- small, medium or large
3 muscles of the thorax
External intercostals
Internal intercostals
Diaphragm
Fibres in the abdominal wall run is _______ to ____________
Different directions to increase strength
3 abdominal wall layers
Rectus, transverse, oblique
Muscles of the abdominal wall
External oblique Internal oblique Transverse abdominis Rectus abdominis Quadratus lumborum
Muscles of the back ____- or _____ the back
Bend or stabilize
Muscle of the back include
Sternocleidomastoid
Trapezius
Deltoid
Latissimus dorsi
