Question | Answer |
occipitofrontalis? | raises of eyebrows |
obricularis oculi? | closing of eyelids, and causes, “crows feet”. |
orbicularis oris? | picked of the lips. |
buccinator? | flattening of the cheeks |
zygomaticus? | smiling muscle |
levator labii superioris? | sneering. |
depressor anguli oris? | frowning. |
mastication? | chewing |
intrinsic tongue muscles? | change the shape of the muscle |
extrinsic tongue muscle? | moves tongue |
sternocleidomastoid? | lateral neck muscle, and prime mover |
erector spinae? | group of muscles on each side of the back |
thoracic muscles? | muscles that move the thorax |
most involved in breathing? | external intercostal.
internal intercostal.
diaphragm.
dome. |
external intercostal? | elevate ribs during inspiration |
internal intercostal? | contact during forced expirations |
diaphragm? | accomplishes quiet breathing |
dome? | shaped muscle, aids in breathing |
abdominal wall muscles? | they flex and rotate the vertebral column, compress the abdominal cavity, and hold the abdominal viscera. |
linea alba? | tendinous area in abdominal area, consists of white connective tissue rather than muscle. |
rectus abdominis? | on each side of the linea alba |
trapezius? | rotates scapula |
serratus anterior? | pulls scapula anteriorly |
pectoralis major ? | adducts and flexes the arm |
latissimus dorsi? | rotated, adducts, and powerfully extends arm. |
Gluteus maximus | buttocks |
quadriceps femoris | extends the leg |
satorius | flexes the thigh |
triceps brachii | extends the forearm |
biceps brachii | flexes the forearm |
brachialis | flexes forearm |
brachioradials | flexes and supinates the forearm |
retinaculum | strong band of fibrous connective tissue that covers the flexor |
flexor carpi | flexes the wrist |
extensor carpi | extends the wrist |
flexor digitorum | flexes the fingers |
extensor digitorum | extends the fingers |
deltoid | attaches the humerus to the scapula |
hamstring | posterior thigh muscles |
gastrocnemius and soleus | from the calf muscle |
calcaneal tendon | flex the foot and toes |
peroneus | lateral muscles of the leg |
intrinsic foot | 20 muscles located within the foot |
contractility | skeletal muscles to shorten with force |
excitability | capacity of skeletal muscles to respond to stimulus |
extensibility | ability to be stretched |
elasticity | ability to recoil to their original resting length |
epimysium | surrounds muscles with connective tissue |
fascia | connective tissue located outside the epimysium |
perimysium | A muscle is composed of numerous visible bundles called muscle fasciculi, which are surrounded by loose connective tissue |
fibers | The fasciculi are composed of single muscle cells |
endomysium | Each fiber is surrounded by a connective tissue sheath called the |
myofibrils | The cytoplasm of each fiber is filled |
actin myofilaments | thin myofilaments. They resemble 2 minute strands of pearls twisted together |
myosin myofilaments | thick myofilaments. They resemble bundles of minute golf clubs. |
sarcomeres | which are joined end to end to form the myofibril |
the resting membrane potential. | The outside of most cell membranes is positively charged compared to the inside of the cell membrane, which is negatively charged. The charge difference across the membrane |
action potential. | When a muscle cell is stimulated the membrane characteristics change briefly. The brief reversal back of the charge |
Motor neurons | are nerve cells that carry action potentials to skeletal muscle fibers |
neuromusclular junction | Axons enter the muscles and branch. Each branch that connects to the muscle forms a |
synapse | near the center of the cell. |
motor unit | A single motor neuron and all the skeletal muscle fibers it innervates |
presynaptic terminal | the muscle fiber |
synaptic cleft | the space between the presynaptic terminal and the muscle cell |
acetylcholine | that secrete a neurotransmitter |
acetylcholinesterase. | The acetylcholine released into the synaptic cleft between the neuron and muscle cell is rapidly broken down by an enzymes |
sliding filament mechanism | The sliding of actin myofilaments past myosin myofilaments during contraction |
Muscle twitch | is a contraction of an entire muscle in response to a stimulus that causes the action potential in one or more muscle fibers. |
threshold | A muscle fiber will not respond to stimulus until that stimulus reaches a level |
all-or-none response. | The phenomenon |
lag phase | The time between application of a stimulus to a motor neuron and the beginning of a contraction |
contraction phase | The time of contraction |
relaxation phase | The time during which the muscle relaxes |
Tetany | where the muscle remains contracted without relaxing. |
recruitment | The increase in number of motor units being activated |