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muscular system ch 9
Chapter 9 The Muscular System
Term | Definition |
---|---|
muscular system | includes the skeletal muscles and accessory structures |
functions of muscular system | provides mobility, provides movement, and produces heat |
endomysium | delicate connective tissue covering each muscle fiber |
fascicles | bundles of muscle fiber |
fascicles | surrounded by perimysiium and bundled into the muscle |
epimysium | connective tissue covering that surrounds muscles as a whole and binds all muscle fibers together |
contraction | what muscle cells are specialized for |
muscle fibers | only shorten to produce movement |
tendons | anchor muscle to bone and other muscles |
tendons | made of dense fibrous connective tissue and a continuation of deep fascia |
tendons | merge with the periosteum to anchor to bone |
sarcolemma | special name for the cell membrane of the muscle cell |
sarcoplasm | special name for cytoplasm of muscle cell |
sarcoplasm | filled with myofibrils and contain sarcomeres |
sarcomeres | the unit of contraction of the myofibrils of the muscle |
myofibrils | long protein bundles that fill the sarcoplasm of a muscle fiber |
muscle fiber | a skeletal muscle cell |
myofilaments | fine protein fibers that make up a myofibril |
z-disc | protein backbone that anchors actin filaments |
actin filaments | thin contractile proteins that interact with myosin |
myosin filaments | thicker contractile proteins |
tintin filaments | protein that anchors myosin to the z-disc |
actin | forms a cross-bride with myosin which shortens the sarcomere |
troponin and tropomyosin | inhibitory proteins that prevent contraction when relaxed |
tropomyosin and troponin | attach to actin and block myosin from forming a cross bridge |
motor nerve | end at each muscle fiber |
axon terminal | enlarged end of the motor neuron and contains sacs of neurotransmitter acetylcholine |
acetylcholine | chemical messenger released from the end of a motor neuron |
synapse | the junction between the axon terminal and the muscle fiber sarcolemma |
exocytosis | when ACh is released across the synapse |
receptors | ACh attaches to this in the sarcolemma |
electrical impulse | ACH causes this in the sarcolemma |
cholinesterase | deactivates ACh |
T-Tubules | tubes that allow signals to travel into the cell |
sarcoplasmic reticulum | stores calcium ions, ER of muscle cell |
contraction | when myosin binds to actin |
origin | where the muscle originates, usually the more stationary of the two ends |
belly | the thick middle part of a muscle |
insertion | opposite end of the origin, crosses at least one joint from the origin |
insertion | determines what the action of the muscle is |
heads | in muscles with more than one belly |
action | the movement a muscle causes when it contracts |
prime mover (protagonist) | the primary muscle that brings about the desired movement |
antagonist | the muscle that does the opposite of the prime mover |
synergist | secondary muscles that bring about the desired movement. assists the prime mover |
thermogenesis | heat production from normal muscle metabolism |
thermogenesis | is due to friction and chemical reactions, increased with increased activity |
maximus | largest |
minimus | smallest |
major | large |
minor | small |
longus | long |
brevis | short |
deltoid | triangular |
rhomboid | diamond shaped |
sarratus | sawtoothed |
trapezius | trapezoidal |
pectoralis | chest |
brachio | upper arm |
radialis | radius bone |
gluteus | buttock |
femoris | femur |
sterno | sternum |
cleido | clavicle |
mastoid | mastoid process |
digiti | fingers or toes |
pollicis | thumb |
hallicus | big toe |
lateralis | lateral |
medialis | medial |
intermedium | middle |
profundus | deep |
superficialis | superficial |
biceps | 2 heads |
triceps | 3 heads |
quadriceps | 4 heads |
rectus | straight |
transverse | sideways/across |
oblique | diagonal |
adductor | adducts |
abductor | abducts |
flexor | flexes |
extensor | extends |
levator | elevates |
head and neck | frontalis, orbicularis oculi, masseter, temporalis, sternocleidomastoid and orbicularis oris |
abdominal wall | rectus abdominis, external oblique, internal oblique, transverse abdominis, and line alba |
shoulder and back | deltoid, pectoralis major, serratus anterior, latissimus dorsi, and trapezius |
upper extremity | brachialis, biceps brachii, triceps brachii, brachioradialis, hand and digit extensors, and hand and digit flexors |
quadriceps femoris | rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis |
glutes | gluetus maximus, gluteus medius, and gluteus minimus |
hamstrings | biceps femoris, semitendinosus, and semimembranosus |
calf | gastrocnemeus, soleus and plantaris |
foot and toe extensors | tibalis anterior |
plantaris | 25% of population does not have one |