A&P chapter 10 exam

terms we need to know

muscle action

aka: muscle effect

agonist

aka: prime mover

antagonist

* opposes the prime mover
* prevents excessive movement
* sometimes relaxes to give prime mover control over movement

antagonistic pair

muscles that act on opposite sides of a joint

antigravity muscles

prevent us from falling over

direct attachment

* little separation between muscle and bone
* muscle and bone connected by collagen fibers

endomysium

* thin sleeve of loose CT around each fiber (muscle cell)
* allows room for capillaries and nerve fibers
* provides chemical environment for fiber and nerve

epimysium

* fibrous sheath surrounding entire muscle
* outer surface integrates with fascia
* inner surface creates projections that form perimysium

extrinsic muscle

muscles isolated from the region on which they act

fascia

* sheet of CT surrounding entire muscle
* separates neighboring muscles or muscle groups from each other and from the subcutaneous tissue
* continuous with tendon which is continuous with periosteum

fixator

* muscle that prevents movement of bone
* gives prime mover something to pull against

fleshy attachment

aka: direct attachment

glycemic control

* skeletal muscles absorb, store, and use glucose which helps regulate blood sugar levels
* reduced muscle mass due to old age, obesity, or disuse associated with type 2 diabetes

indirect attachment

* tendons connect muscle to bone
* collagen fibers of the endomysium, perimysium, and epimysium continue into the tendon and from there into periosteum

insertion

bony attachment at mobile end of muscle

intrinsic muscle

muscles entirely contained within the region on which they act (both the origin & insertion are here)

muscle

* Greek for “little mouse”
* 3 kinds: skeletal, cardiac, smooth
* purpose: to convert the chemical energy of ATP into the mechanical energy of motion

muscle compartments

groupings of muscles, nerves, and blood vessels in your arms and legs

muscular system

refers to the skeletal muscles

myology

the study of skeletal muscles/muscular system

origin

bony attachment at stationary end of muscle

perimysium

* thicker layer of CT around bundles of fibers (fascicles)
* carries nerves, blood vessels, and stretch receptors

prime mover

muscle that produces most of the force during a movement

sphincters

internal muscular rings that control the movement of food, blood, and other materials within the body

synergist

* muscle that aids the prime mover
* may contribute additional force, modify the direction of movement, or stabilize the joint

tendon

a fibrous connective tissue that attaches muscle to bone

belly

thicker, middle region of muscle between origin and insertion → site of contraction