The muscle system
names of all the
muscles and categorized based on location and their actions
Muscles of head chart
3 types of muscle tissue
Skeletal: cells are long,cylindrical,parallel and multinucleated, attached by tendons to bones, striated visible banding and voluntary subject to conscious control.
Cardiac: cells are long,cylindrical,branched, has single central nucleus, has striations, forms heart wall and joined to another cell at intercalated disc involuntary.
Smooth: spindle shaped cells with single central nucleus, has n striations, found mainly in hollow walls of organs and eyes control size of pupil and it is involuntary.
body movement terminology structure and organizational levels of the skeletal muscle
Neuromuscular Junction
Connection of the nerves and skeletal muscle
Synapse is the connection between nerve with muscle and other organs.
Axon is the long portion of the nerve release a chemical called a neurontransmitter.
Neurotransmitter is chemical messenger stored and released by synaptic vesicles into synaptic cleft.
Synaptic cleft is a gap between neuron and sarcolemma.
Acetylcholine is a neurotransmitter for skeletal muscle.
Axonal termials ends of axon many branches, synaptic end bulbs are found in axonal terminal.
Motor end plates are region across synaptic cleft rom the synaptic end bulbs
Muscle contractions are nerve impulse reaches synaptic end bulbs and causes synaptic vesicles to fuse with neurolemma and releases
Ach diffuses across synaptic cleft and binds with receptor on motor end plate of the muscle cell.
This causes receptor to change shape and opens Na+ channel in sarcolemma.
Electrical current is generated and is carried along sarcolemma causes action potential.
Muscle Relaxation
Ach is broken down by an enzyme called acetylcholinesterase.
Action potentials are no longer generated so the Ca++ channels is SR close
Frontalis is the raise of the eyebrows
Orbicularis oculi is the skin and muscle around the mouth and blinks and closes as well.
Zygomaticus raises the corner of mouth
Buccinator is the compresses cheek as in whistling and sucking, holds food between teeth during chewing/sucking or sucking cheek in like a fish face.
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Platysma pulls corners of the mouth inferiorly
temporalis is the close jaw
orbicularis oris closes and protrudes the lips
Masseter closes the jaw
sternocleidomastoid flexes the neck or rotates the head.
Muscles of the trunk chart
Pectoralis major moves and flexes humerus.
Rectus Abdominis flexes vertebral column.
Latissimus Dorsi extends and moves humerus.
trapezius extends the neck and moves scapula.
External Obliques flexes/rotates vertebral column.
Erector spinae extends the back.
Muscles of arm chart
bicep brachii lexes the elbow.
Deltoid is moves the shoulder and arm.
Extensor Digitorium extends toes and flexes foot.
Tricep Brachii extends the elbow.
Flexor Carpi Radialis flexes the wrist.
Flexor Carpi Ulnaris flexes the wrist.
Extensor Carpi Radialis extends the wrist and adducts as well.
Muscles of the thigh and leg chart
Iliopsoas flexes hip.
Adductor Muscles adduct the thigh.
Gluteus Maximus is the booty.
Tibialis Anterior is the invert toe and dorsiflexes.
Extensor Digitorium Longus extends is toes.
Sartorius flexes the thigh on the hip
Quadracep group extends the knee, flexes the thigh.
Hamstring extends the hip when trunk is fixed
Gastrocnemius is the calf muscle .
Soleus is the calf, heel used for walking.
Physiology of muscle contraction
Nerve impulse or action potential travels down Sarcolemma and into T-tubules causing sarcoplasmic reticulum to release Ca++ binds to actin myofilament, exposing the myosin binding site.
Ca++ binds to actin myofilament, exposing the myosin binding site.
Myosin attaches to actin, forming actin/myosin crossbridges.
Myosin head more toward M line of sarcomere, pulling actin filaments past myosin.
This action is repeated many times powered by ATP.
zLINES GET CLOSER TOGETHEER AS ACTIN AND MYOSIN FILAMENTS SLIDE PAST EACH OTHER AND SAROMERES SHRETN, SHORTENING THE ENTIRE MYOSFIBRIL.