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My Notes
Mrs eastams Class Notes
Term | Definition |
---|---|
Contractibility | Ability of skeletal muscle to shorten with force. |
Excitability | capacity of skeletal muscle to respond to a stimulus. |
Extensibility | ability to be stretched. |
Elasticity | ability to recoil to original resting length after they have been stretched. |
epimysium | surrounds skeletal muscle and is a connective tissue sheath. |
fascia | another connective tissue located outside the epimysium. it surrounds and seperates muscles. |
perimysium | loose connective tissue tht surrounds fasiculi. |
fibers | single muscle cells |
endomysium | connective tissue sheath tht surrounds fibers. |
myofibrils | threadlike structure tht extends from one end of the fiber to the other. |
actin myofilaments | thin, resemble 2 minute strands of pearls twisted together. |
myosin myofilaments | thick, resemble bundles of minute golf clubs. |
sarcomeres | highly ordered units which are joined end to end to form the myofibril. |
resting membrane potential | charge difference across the membrane. |
action potential | the brief reversal back of the charge. |
motor nuerons | nerve cells that carry action potentials to skeletal muscle fibers. |
belly | portion of muscle between the origin and the insertion |
Erector spinae | of muscles on each side of the back |
Thoracic Muscles | muscles that move the thorax |
Diaphragm | accomplishes quiet breathing |
Trapezius | rotates scapula |
Serratus anterior | pulls scapula anteriorly |
Pectoralis major | adducts and flexes the arm |
Latissimus dorsi | medially rotates, adducts, and powerfully extends the arm |
Biceps brachii | flexes the forearm |
Triceps brachii | extends the forearm |
Brachialis | flexes forearm |
Brachioradialis | flexes and supinates the forearm |
Retinaculum | strong band of fibrous connective tissue that covers the flexor and extensor tendons |
Flexor carpi | flexes the wrist |
Extensor carpi | extends the wrist |
Flexor digitorum | flexes the fingers |
Extensor digitorum | extends the fingers |
the intrinsic hand muscles | 19 hand muscles |
Gluteus maximus | buttocks |
Gluteus medius | hip muscle and common injection site |
Quadriceps femoris | extends the leg |
Sartorius | flexes the thigh |
Hamstring muscles | flexes the leg and extends the thigh |
Gastrocnemius and soleus | form the calf muscle |
calcaneal tendon | Flex the foot and toes |
peroneus muscles | turning the lateral side of the foot outward |
intrinsic foot muscles | flex extend, abduct, and adduct the toes |
synapse | near center of cell |
motor unit | single motor nueron mujscle fibers |
presynaptic terminal | space between muscle cell |
synaptic vessels | secretes synaptic cleft |
acetylcholine | nuerotransmitter |
acetylcholinesterase | enzymes tht rapidly breaks down |
sliding filament mechanism | sliding of actin myofilaments |
muscle twitch | contraction of entire muscle |
threshold | point muscle contracts fully |
lag phase | time between stimulis to motor nueron |
contraction phase | time of contraction |
relaxation phase | time which muscle relaxes |
tetany | muscles remain contracted |
recruitment | increase in number of motor units |
atp | needed for energy |
atp | produced in mitochondria |
atp | short lived |
atp | unstable |
atp | degenerates to more stable adp |
creatine phosphate | high energy molecule |
anaerobic respiration | without oxygen |
aerobic respiration | with oxygen |
oxygen dept | amount of oxygen needed for chemical reaction |
muscle fatigue | mucles tire faster than oxygen can b produced |
isometric | equal distance |
isotonic | equal tension |
muscle tone | constant tension of muscles |
origin | head |
insertion | end of muscle undergoing most work |
belly | between origin and insertion |
synergists | muscles tht work together |
antagonist | muscles tht work in opposition |
prime mover | a muscle tht plays as the major role |