Question | Answer |
Occipitofrontalis | raise the eyebrows |
Orbicularis oculi | closes the eyelids and causes “crows feet” wrinkles in the skin at the lateral corners of the eye. |
Orbicularis oris | puckers the lips. |
Buccinator | flattens the cheeks. Trumpeter’s muscle. |
Zygomaticus | smiling muscle. |
Levator labii superioris | sneering |
Depressor anguli oris | frowning |
Mastication | chewing |
Sternocleidomastoid | rotates and abducts head |
Erector spinae | muscles on each side of back keeping it straight |
Diaphragm | accomplishes quiet breathing |
External intercostals | elevate the ribs during inspiration |
Internal intercostals | contract during forced expiration |
Intrinsic Tongue Muscles | changes the shape of the tonuge |
Extrinsic Tongue Muscles | move the tongue |
Dome | shaped muscle aiding breathing |
Trapezius | rotates scapula |
Serratus anterior | pulls scapula anteriorly |
Pectoralis major | adducts and flexes the muscle |
Latissimus dorsi | powerfully extends the arm |
Deltoid | major abductor of the upper limb |
Triceps brachii | extends the forearm |
Biceps brachii | flexes the forearm (anterior compartment) |
Brachialis | flexes forearm |
Brachioradialis | flexes and supinates the forearm |
Flexor carpi | flexes the wrist |
extensor carpi | extends the wrists |
flexor digitorum | flexes the fingers |
extensor digitorum | extends the fingers |
Gluteus maximus | buttocks |
Quadriceps femoris | extends the leg |
Sartorius | tailors muscle. flexes the thigh |
Hamstring muscles | posterior thigh muscles; flexes the leg and extends the thigh |
Gastrocnemius and soleus | form the calf muscle. |
intrinsic foot muscles | 20 muscles located within the foot |
peroneus muscles | the laternal muscles of the leg |
Contractility | skeletal muscle to shorten with force |
Excitability | skeletal muscle to respond to a stimulus. |
Extensibility | ability to be stretched. |
Elasticity | recoil to their original resting |
epimysium | surrounds skeletal muscle |
Fascia | connective tissue outside the epimysium |
perimysium. | loose connective tissue |
endomysium. | surrounds each muscle fiber |
myofibrils | cytoplasm of each fiber |
actin myofilaments | thin myofilaments |
myosin myofilaments | thick myofilaments |
sarcomeres | basic structural and functional unit of the muscle. |
resting membrane potential. | charged difference between cell membranes |
action potential. | brief reversal back of the |
Motor neurons | nerve cells that carry action potentials to skeletal muscle fibers. |
neuromusclular junction or synapse | branch that connects to the muscle forms |
motor unit | single motor neuron and all the skeletal muscle fibers it innervates |
presynaptic terminal | enlarged nerve terminal |
postsynaptic terminal. | the space between the presynaptic terminal and the muscle cell |
synaptic vesicles | presynaptic terminal contains this |
acetylcholine. | this secrete a neurotransmitter |
acetylcholinesterase. | enzymes that rapidly break down acetylcholine |
sliding filament mechanism | sliding of actin myofilaments past myosin myofilaments during contraction |
Muscle twitch | contraction of an entire muscle |
threshold | point the muscle fiber will contract maximally |
lag phase. | time between application of a stimulus and beginning of a contraction |
contraction phase | time of contraction |
relaxation phase | time of relaxation |
Tetany | when muscle remains contracted |
recruitment | increase in number of motor units |
creatine phosphate. | high energy molecule |
Anaerobic respiration | without oxygen |
Aerobic respiration | with oxygen |
oxygen debt | amount of oxygen needed to convert lactic to glucose |
Muscle fatigue | results when ATP is used |
isometric | the length of the muscle does not change, but the amount of tension increases during the contraction process. |
isotonic | the amount of tension produced by the muscle is constant during contraction, but the length of the muscle changes. |
muscle tone | constant tension produced by muscles |
Fast-twitch fibers | contract quickly and fatigue quickly |
13. Slow-twitch fibers | contract more slowly and release slowly |
origin | stationary end of muscle |