Chapter 5 (Muscular System) Flashcards
What are muscle names based off of?
- Location
- Shape
- Action
- # of heads or divisions
- Attachments= origin/insertion
- Direction of fibers
- Size
When a muscle contracts it knows no direction: it simply ____?
shortens
What is the more movable bone?
Insertion (most distal) which moves toward the origin
What is the more stable bone?
Origin (most proximal)
What is the reversal of a muscle action ?
When the origin moves towards the insertion
Long and thin, fibers run the entire length of the muscle
Strap muscle (parallel)
Spindle shape- wide mouth tapered ends (muscle)
Fusiform muscle (parallel)
Four sided, flat (muscle)
Rhomboidal muscle (parallel)
Flat, fan shaped, fibers radiating from a narrow attachment
Triangular muscle (parallel)
looks like one side of a feather (muscle)
Unipennate (oblique)
pattern common feather (muscle)
Bipennate (oblique)
Many tendons (muscle)
Multipennate (oblique)
What is normal resting length?
- when the length is unstimulated
2. When there are no forces or stresses on it
What are the four functional characteristics of muscle ?
- Irritability
- Contractility
- Extensibility
- Elasticity
Ability to respond to a stimulus
- Contracts when stimulated, motor nerve or electric current
Irritability
Ability to shorten or contract
- Produces tension between ends
- The muscle shortens, stays the same, or lengthens
Contractile
Ability of a muscle to stretch or lengthen when force is applied
Extensibility