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muscular systems
muscles
Term | Definition |
---|---|
muscle cells | muscle fibers |
slow twitch fibers | dark meat; legs of chicken |
fast twitch fibers | white meat; breast of chicken |
isotonic muscle contraction | same tension but length changes |
isometric muscle contraction | tension changes but length does not |
muscle tone does what | keep head up and back straight |
two types of muscle contractions | isotonic & isometric |
anaerobic | without oxygen |
aerobic | within oxygen |
four major muscle functional characteristics | contractility excitability extensibility elasticity |
fascia | located outside of the epimysium and separates muscles |
epimysium | skeletal muscles surrounded by connective tissue sheath |
perimysium | surrounds the fascicle |
fascicle | the composition of a muscle in bundles; bundles of muscle fibers |
endomysium | surrounds each fiber |
two major kinds of protein fibers | actin & myosin |
sarcomeres | actin and myosin myofilaments form highly ordered units which are joined end to end to form the myofibril |
extensibility | ability to be stretched |
elasticity | ability to recoil |
contractility | ability to shorten with force |
excitability | responds to a stimulus |
tendon | attaches muscle to bone |
ligament | attaches bone to bone |
motor neurons | carry action potentials to muscle fibers |
action potential | brief reversal back of the charge |
resting membrane potential | charge difference across the membrane |
synaptic cleft location | between the presynaptic terminal and the muscle cell |
acetylcholine | presynaptic terminal contains synaptic vesicles that secrete a neurotransmitter |
Z line | attachment site for actin |
A band | extends the length of myosin; the darker central region |
I band | located on each side of the Z line ; consist of actin |
origin | most stationary end of the muscle |
insertion | undergoes the greatest amount of movement |
belly | between the origin and insertion |
points of attachment of each muscle | origin and insertion |
what are the origin and insertion connected to? | to bone by tendons |
tetany | where the muscle remains retracted without relaxing. |
recruitment | increase in number of motor units being activated |
threshold | point at while muscle fiber will contract maximally |
muscle contraction occurs when | actin and myosin myofilaments slide past each other causing the sarcomere to shorten |
ATP stands for | adenosine triphosphate |
ATP is produced where | mitochondria |
ATP is not stable (true or false) | true |
nomenclatures of muscles are descriptive in what ways | they tell size, shape, location, origin, insertion, function, etc. |
synergists | muscles that work together |
antagonist | muscles that work opposite of each other |
prime mover | among synergist if one muscle plays a major role in accomplishing a desired movement |
Orbicularis oris | puckers lips |
Buccinator | flattens cheeks |
Orbicularis oris and buccinator are | kissing muscles |
Zygomaticus | smiling muscles |
Levator labii superioris | sneering |
Depressor anguli oris | frowning |
4 pairs of mastication muscles: | 2 pair of pterygoids, temporalis, and masseter |
Mastication | chewing |
Intrinsic Tongue Muscles | shape |
Extrinsic Tongue Muscles | movement |
Neck Muscle | Sternocleidomastoid |
lateral neck muscle and prime mover | sternocleidomastoid |
Trunk Muscles | Erector spinae |
External intercostals | elevate the ribs during inspiration. |
Internal intercostals | contract during forced expiration. |
Diaphragm | Dome-shaped muscle. Aids in breathing |
linea alba | tendinous area of the abdominal wall |
rectus abdominis is located here | On each side of the linea alba |
Trapezius | rotates scapula |
Serratus anterior | pulls scapula anteriorly |
Pectoralis major | adducts and flexes the arm |
Deltoid | attaches the humerus to the scapula and clavicle, and is the major abductor of the upper limb |
intrinsic hand muscles | 19 hand muscles |
Interossi muscles | located between the metacarpals, are responsible for abduction and adduction of the fingers |
Gluteus maximus | buttocks. |
Sartorius | flexes the thigh |
Hamstring muscles | posterior thigh muscles; flexes the leg and extends the thigh |
Gastrocnemius and soleus | form the calf muscle. |