Chapter 2 Flashcards
There are about how many ….. skeletal muscles that usually work in cooperation with each other to perform opposite actions at the joints they cross
215
Muscles work in groups rather than independently to achieve a given joint motion
Aggregate muscle action
Muscles also have four other functions… what are they?
- provide protection
- contribute to support & posture
- Produce a major portion of body heat
- Provide dynamic stability
Muscles are usually named based on their:
- visual appearance
- functions
- anatomical locations
True or false: A muscle can be identified by a combination of two or more of these features
true
What does maximus and minimus mean? what does longus and brevis mean? what characteristics is this dsecribing?
Maximus- large
Minimus - small
Longus- Long
Brevis- short
Visual appearance: Directional fibers: What do the following mean?
Oblique
Rectus
Transverse
Oblique- slanting fibers
Rectus - Parallel fibers
Transverse - horizontal fibers
Skeletal muscle is made up of what ? They are stimulated by what when they are contracted?
They are made of up individual muscle fibers.; A motor nerve.
Muscle fiber arrangement affects:
- Muscle’s ability to exert force
- Cross-sectional- area
- Range through which the muscle can effectively exert force
4: Longer muscles can shorten through a greater range: move joints through larger range of motion
What are the two major types of fiber arrangements?
- Parallel & Pennate
Describe the diffrence between parallel and pennate fibers
Parallel fibers are fibers that are parallel in length to the muscle. They produce greater movement than simialr sized pennate muscles
Pennate fibers on the other hand are fibers that are shorter and arranged obliquely to their tendons. They have a greater cross sectional area; thus greater power.
The part of the muscle that attaches farthest from the midline or center of the body
insertion
The part of the muscle that attaches closest to the midline or center of the body
orgin
Fibrous connective tissue that connects muscles to bones and other structures
Tendon
Development of tension in a muscle as a result of a stimulus
Contraction
There are two types of muscle contraction? What are they?
Isotonic and isometric
There are 3 primary things a muscle contraction focuses on?
Cause; control; and prevent of a joint movement
What happens during an isometric concentration?
During an isometric concentration, muscle tension is being created; however, the joint angles remain constant. In other words, I am holding a weight in a stable condition. I am not moving my arm up or down. Therefore, my muscles are contracting and creating tension and being used to stay in that stable condition
Muscle develops active tension but joint angles remain constant (static contraction)
Isometric contraction
There are two types of isotonic contraction? What are they?
Eccentric & concentric
Muscle develops active tension to either cause or control joint movements (dynamic stability)
isotonic contraction
What is another name for static contraction?
isometric contraction
What is another name for dynamic contraction?
isotonic contraction
muscle develops active tension as it shortens
Concentric contraction