Human Anatomy Chapter 11

Start Studying!

Terms

undefined, object

copy deck

The muscular system refers ONLY to what muscle tissue: Skeletal muscle
(not cardiac or smooth)
lever systems explain...: how muscles act with or against each other to bring about movements.
A lever is...: a rigid bar that moves on a FIXED POINT.
the fixed point around which a lever moves is called a: Fulcrum
What is the applied force on a lever called: effort
the purpose of applying EFFORT is to move a resistance or..: load.
In human lever systems, what is the: -levers? -fulcrums? -effort? -load?: Bones

Joints

Muscle contraction

The weight of the body part itself + any other weight.
Mechanical ADVANTAGE is characterized as having the load (close/far) from the fulcrum and providing the effort (close/far) from the fulcrum.: close, far.
What is an example of a mechanical advantage lever system?: Car Jack

(when effort is farther from the fulcrum, than is the load, a smaller effort can lift a larger load)
Mechanical disadvantage is characterized as having the load (closer/further) from the fulcrum than the effort?: Further
What is an example of mechanical disadvantage?: Carrying a shovel full of dirt.
From NOTES: "The operation of skelletal muscles involves...: leverage"
First class levers -Analogous name -relative positions - Mechanical example - class example - mechanical advantage/disadvantage?: see-saw levers

Load, Fulcrum, Effort

Scisors

Falling asleep (muscles keep head from falling forward)

Can work under both.
Second class levers -Order of forces -Mechanical example -Class example - Mechanical advantage/disadvantage: Fulcrum, Load, Effort

Wheelbarrow

Standing on tip-toes

ALL AT MECHANICAL ADVANTAGE!
Second class levers -Rare/Common - Advantages - Disadvantages: Very rare in the human body

Stength (Very strong system (Only mechanical advantage)

Speed and motion are sacraficed.
Third-class levers -Order of forces -Mechanical example -Class example -Mechanical avantage/disadvantage: Load, Effort, Fulcrum

Tweezers

Lifting weights around the elbow. (bicep workout)

Mechanical DISadvantage ALWAYS!
Third class levers -Rare/Common -Strong/Weak: The most common of lever systems

Weaker than second class but they have better motion and speed.
What are the classes of fassicle arrangement (4): Parallel
Convergent
Pennate
Circular
Parallel Fassicles of Muscles -Arrangement -Strength/endurance -example: fasicles run along the long axis of the muscle itself.

Not very strong, good endurance

Sartorius, Rectus Abdominus (bicep, sternocleidomastoid)
Convergent fassicles -Arrangement -Strength/endurance -examples: Have WIDE ORIGINS and NARROW INSERTIONS

Stronger than parallel

Pectoralis major
Pennate -Arrangement -Strength/endurance -Example: fasicles are short and attach obliquely to a tendon that runs the length of the muscle.
Pennate fassicles can be either unipennate, bipennate or multipennate depending on: the number of sides in which it attaches to the tendon.
Circular Fasicles -Arrangement -example: Concentric rings around orifice

Obicularis Oculi, Obicularis Ori
According to Tillman, circular fassicles are not _________________ b/c _________.: Sphincters;

circular fasicles are sphincteral (circular) but NOT classified as sphincters.
What is a MAJOR difference between parallel/convergent arrangements and pennate/circular.: in parallel/convergent fasicle arrangements the muscles extend the length of the muscle.
Skelletal Muscles are FUNCTIONALLY classified into four categories. What are they?: Agonists
Antagonists
Synergists
Fixators
Agonist -often called - a muscle that has the... -example: Primary mover

major responsibility for a specific motion.

Biceps Brachii
Antagonist -often called - a muscle that has the... -example: "against the leader"

job of opposing or reversing a particular movement.

Triceps Brachii
Synergist -functions: 1.) To add a little more strength to the agonists.

2.) MORE IMPORTANTLY, to stabilize the movement. Several Agonists articulate in several places and cause unwanted movements. Synergists stop these unwanted movements.
Fixators -Function: Fixators are considered a class of synergist that function to hold a bone firmly in place when an agonist acts on it.
Muscles can be named according to all of the following:: Location
Shape
Size
Direction of fassicles
Location of attachments
Number of origins
Actions
Recall that all muscles develop from what embryonic layer: mesoderm
Musculature of the VISCERAL ORGANS includes both... This muscle originates from the...: skeletal muscle and cardiac muscle.

splanchnic muscles (early gut)
Musculature of the PHARNGEAL ARCH MUSCLES develop around the...: embryonic pharnyx (from the 4-7th somitomeres.
Musculature for the axial muscles develop from: myotomes and some somitomeres.
Musculature of the limb muscles develops from...: the lateral parts of nearby myotomes.

Start Studying!

Deck Info

Number of cards 36