Question | Answer |
contracility | shorten with force |
excitability | respond to a stimulus |
extensibility | stretched |
elasticity | go back to original after being stretched |
epimysium | connective tissue sheath around each skeletal muscle |
fascia | outside the epimysium, surrounds& separates muscles |
perimysium | loose connective tissue |
muscle fasciculi | visible bundles |
fibers | single muscle cells |
endomysium | connective tissue sheath surrounding fiber |
myofibrils | extends from one end of the fiber to the other |
actin myofilaments | thin myofilaments |
myosin myofilaments | thick myofilaments |
sarcomeres | highly ordered units |
resting membrane potential | charge difference across membrane |
action potential | reversal back of the charge |
motor neurons | nerve cells that carry action potentials |
neuromuscular junction/ synapse | forms when branch connects to muscle |
motor unit | single motor neuron |
presynaptic terminal | enlarged nerve terminal |
synaptic cleft | space between the presynaptic terminal and muscle cell |
postsynaptic terminal | muscle fiber |
synaptic vesicles | in every presynaptic terminal |
acetylcholine | neurotransmitter |
acetylcholinesterase | enzyme |
sliding filament mechanism | sliding of actin myofilaments |
muscle twitch | contraction of muscle |
threshold | muscle fiber contract maximally |
all- or- none response | threshold |
lag phase | beginning of contraction |
contraction phase | time of contraction |
relaxation phase | muscle relaxes |
tetany | the muscle remains contracted without relaxing |
recruitment | increase of in number of units |
creatine phosphate | high energy molecule |
anaerobic repiration | without oxygen |
aerobic respiration | with oxygen |
oxygen debt | amount of oxygen needed in chemical reactions |
muscle fatigue | ATP is used during muscle contraction |
isometric | equal distance |
isotonic | equal tension |
muscle tone | constant tension produced by muscle |
fast twitch fibers | contract and fatigue quickly |
slow twitch fibers | contract more slowly |
origin | most stationary end of the muscle |
insertion | end of the muscle undergoing |
belly | muscle between origin and insertion |
synergists | muscles that work together |
antagonists | muscles that work in opposition to each other |
prime mover | accomplishing desired moevment |
occipitofrontalis | raises the eyebrow |
orbicularis oculi | closes the eyelid and creates the wrinkles next to your eye |
orbicularis oris | puckers the lips |
buccinator | flattens the cheeks |
zygomaticus | smiling muscle |
levator labii superioris | sneering |
depressor anguli oris | frowning |
mastication | chewing |
intrinsic tongue muscles | change the shape of tongue |
extrinsic tongue muscles | move the tongue |
sternocleidomastoid | lateral neck muscle and prime mover |
erector spine | group of muscles on each side of back |
external intercostals | elevate the ribs during inspiration |
internal intercostals | contract during forced expiration |
diaphragm | quiet breathing |
linea alba | tendinous area of abdominal wall |
rectus abdominis | on each side of the linea alba |
tendinous inscriptions | cross the rectus abdominis at 3 or more locations |
trapezius | rotates scapula |
serratus anterior | pulls scapula anteriorly |
pectorallis major | attaches the arm to the thorax |
latissimus dorsi muscles | attaches the arm to the thorax |
pectorallis major | adducts and flexes the arm |
latissimus dorsi | medially rotates, adducts, and powerfully extends the arm |
deltoid | attaches the humerus to the scapula and clavicle |
triceps brachii | extends the forearm |
biceps brachii | flexes the forearm |
brachialis | flexes forearm |
brachioradialis | flexes and supinates the forearm |
retinaculum | strong band of fibrous connective tissue |
flexor carpi | flexes the wrist |
extensor carpi | extends wrist |
flexor digitorum | flexes the fingers |
extensor digitorum | extends fingers |
intrinsic hand muscles | 19 hand muscles |
interossi | abduction and adduction of fingers |
gluteus maximus | buttocks |
quadriceps femoris | extends the leg |
sartorius | flexes the thigh |
hamstring | flexes leg and extends thigh |
gastrocnemius | form calf muscle |
intrinsic foot | 20 muscles located in the foot |