muscles vocab Flashcards
antagonist
These muscles act in opposition to the movement generated by the agonists and are responsible for returning a limb to its initial position
hamstrings
any one of the three posterior thigh muscles in between the hip and the knee (from medial to lateral: semimembranosus, semitendinous, and biceps femoris)
belly
the widest part of a muscle
insertion
the place where one end of a muscle is attached to the freely moving bone of its joint
serratus anterior
very thin and covers the side of the ribcage. also known as the boxer muscle
biceps brachii
commonly known as the biceps, is a large, thick muscle on the ventral portion of the upper arm
latissimus dorsi
a broad, flat muscle occupying most of the lower posterior thorax. the muscles primary function is to move the upper extremity, but it is also considered an accessory muscle of respiration.
semitendinosus
one of the three muscles that make up the hamstrings muscle group, and it is located at the posterior and medial aspect of the thigh. The semitendinosus is so named due to it having a long tendon of insertion
sternocledidomastoids
each of a pair of long muscles that connect the sternum, clavicle, and mastoid process of the temporal bone and serve to turn and nod the head
biceps femoris
a muscle of the posterior compartment of the thigh, and lies in the posterolateral aspect
complete tetany
The stimulus frequency is so high that the relaxation phase disappears completely, contractions become continuous.
myocyte
a muscle cell
synaptic vesicle
small, electron-lucent vesicles that are clustered at presynaptic terminals. they store neurotransmitters and release them by calcium-triggered exocytosis
conductivity
ability to cross space in between neurons
myofibril
a cylindrical bundle of contractile filaments within the skeletal muscle cell. they myofibrils are composed of individual contractile proteins called myofilaments
temporal summation
the effects of impulses received at the same place can add up if the impulses are received in close temporal succession
contractility
the ability of muscle cells to forcefully shorten
myofilament
threadlike structures that comprise the myofibril inside the muscle cell. there are 2 main types of myofilaments: thin filaments and thick filaments. in skeletal muscle, the myofilaments are arranged in a repeating pattern of light and dark bands
tendon
a flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to bone
contraction phase
a single muscle twitch has a latent period, a contraction phase when tension increases, and a relaxation phase when tension decreases
myoglobin
a protein that’s found in striated muscles, which includes skeletal muscles and heart muscle. Its main function is to supply oxygen to myocytes
elasticity
the ability to recoil or bounce back to the muscle’s original length after being stretched
myosin
a fibrous protein that forms (together with actin) the contractile filaments of muscle cells and is also involved in motion in other types of cells
endomysium
the key element that separates single muscle fibres from one another. it allows their autonomous gliding during muscle contraction
myosin ATPase
an enzyme that causes ATP hydrolysis which provides energy for actomyosin contraction
epimysium
a sheath of fibrous elastic tissue surrounding a muscles
neuromuscular junction
a synaptic connection between the terminal end of a motor nerve and a muscle (skeletal/ smooth/ cardiac)
threshold stimulus
the minimum strength required for the stimulus to initiate the response of muscle contraction
oxygen debt
the difference between the amount of oxygen needed by the muscles and the actual amount present
titan
a molecular spring in muscle cells. Titin binds calcium at specific sites, thereby increasing its stiffness
extensibility
the ability of a muscle to be stretched
masseter
a muscle which runs through the rear part of the cheek from the temporal bone to the lower jaw on each side and closes the jaw in chewing
synergist
Assists the agonists muscle or “primary mover” for a specific action of a joining. this muscle is not the main muscle involved in the action, but works in synergy with the primary muscle.
deltoid
a large triangular-shaped muscle that lies over the glenohumeral joint and which gives the shoulder its rounded contour
origin (head)
The proximal site that stays more stable and relatively fixed during muscle contraction. the head is a portion at the end of the origin muscle where it fixes to the bone
temporalis
A fan-shaped muscle which runs from the side of the skull to the back of the lower jaw and is involved in closing the mouth and chewing
