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Muscular Gladis Vazquez Period 5 - Coggle Diagram
Muscular Gladis Vazquez Period 5
Major Functions of Muscular System
Flexion: decrease in the angle btw. bones at joint
Extenstion: increase in the angle between bones at joints
Synergists: muscles that assist prime mover
Antagonists muscles that oppose an action
3 Types of Muscles & their Functions
Smooth
movement of viscera, peristalsis, vasoconstriction
walls of hollow viscera, blood vessels
Cardiac
pumping action of the heart
walls of the heart
Skeletal
movement of bones at joints, maintenance of posture
skeletal muscles
Skeletal Muscle (including facials)
Temporalis: close jaw, elevates & retracts mandible
Zygomaticus: smiling muscles, raises lateral comers of mouth
Orbicularos Oris: close lips, kissing, whistling
Buccinator: compress chest
Platysma: tense skin if neck, pulls lower lip back & down
Masseter: prim mover of jaw closure, elevates mandible
Orbicularis Oculi: close eyes, blink, squinting
Frontal Belly: wrinkles forehead, raise eyebrows
Pectoralis Major: size & location
Deltoid: shape
Biceps brachii: number of attachments and location
Sternocleidomastoid: attchements; sterum, clavicle, mastoid process
External Oblique: location & direction of fibers
Sarcomere
myofibrils made up of many units which are sarcomere
extends from one Z line to the next
I Bands (light bands): actin filaments, anchored to Z lines
A Bands ( dark bands): overlapping thick and thin filaments
Neuromuscular Junction
a synapse between major neuron and a muscle fiber that it regulates
motor neuron contains mitochondria & synaptic vesicles
neurotransmitters: neuron communicates with muscle fibers
Synapse: muscle fibers connected to axon of a motor neuron
Sliding Filament Theory of Muscle Contraction
Thick Filaments: consist of protien myosin
Thin Filaments: in myofibrils are mainly composed of protein actin ( contains troponin & tropomyosin )
Acetylcholine: neurotansmitter for skeletal muscle fibers contraction at the neuromuscular junctions
Action Potential in Muscle Fiber
cylindrical muscle cell
fibers respond to sitmulation by contracting
sarcolemma is a cell membrane of muscle fiber
Striations is the organization of filaments
SR associated with transverse (T) tubules
Muscle Covering
Skeletal
each muscle cell is called endomysium separates single muscle fibers from one another overlies the sarcolemma
fascia ( blends with epimysium) layer of connective tissue around each skeletal muscle