Muscular System
Muscles of Head
Frontalis- muscles help to move eye brows.
Temporlalis- muscle functions to move mandible .
Orbicularis Oculi-muscle that controls the eye lids.
Orbicularis Oris- Control the movements of the mouth and lips
Zygomaticus- Draws the angles of the mouth superiorly and posteriorly.
Masseter- Puts the mandible upward.
Sternocleidomastoid- rotation of the head and flexion of the neck.
Platysma-Pulling of the corner lips
Buccinator- compresses the cheeks
Muscles of Trunk Chart
Pectoralis Major- helps with the movement of the humorous.
Trapezius-is the active movement muscle.
Rectus Abdominis- pulls the ribs and pelvis
External Obliques-helps rotate the trunk and pull the chest.Compresses the abdominal cavity.
Latissimus Dorsi-is responsible for extension and adduction
Erector Spinal-Contraction of both sides results in erect posture.
Muscles of Arm
Bicep Brachii- movement of the forearm.
Tricep Brachii-extension muscle of elbow joint and antagonist of the bicep.
Deltoid-contraction of the anterior fibers.
Flexor Carpi Radialis- Providing flexion of the wrist.
Flexor Digitorium superficiali-flexion of the middle phalanges.
Flexor Carpi Ulnaris- flew and adduct of hand.
Extensor Digitorium- keep the extensors tendons aligned.
Extensor Carpi Radialis-abducts and extends wrist
Muscles of Thigh and leg
Iliosoas- Flxing trunk and thigh.
Sartorius- weak bone flexor
Adductor Muscles-presses thigh together.
Quadricep Group- climbing, running and jumping
Gluteus Maximus-climbing and running.
Hamstring- Kicking a ball.
Tibialis Anterior- Flexes foot.
Gastrocnemius-stand on tip toes.
Extensor Digitorium Longus-Flexes Foot.
Soleus- Point Foot.
Muscle Types
Skeletal
Cells are long and cyndrical
Attached by tendons to bones
Striated- Visble Bonding
Cardiac-Cells are long cyndrical and branches out.
Has striations
Forms Heart wall.
Smooth- Spindle shaped cells with single central nucleus
Has no striations
Physiology of Muscle Contraction
Muscle Contraction
Nerve impulse reaches synaptic end bulbs and causes synaptic vessel to fuse neurolemma.
Ach diffuses accrocs synaptic cleft and binds with receptors
Causes receptor to change.
electrical current is generated,
The sliding filament theory
Nerve Impulse or action potential travels down sarcolemma and into T-tubules,
Ca++ binds to actin myofilament exposing the myosin binding binding site.
Myosin attaches top actin forming actin cross bridges.
This actin is repeated many times powered by ATP.
Muscle Relaxation- Ach is broken down by enzyme called acetylcholine
Actin potentials and no longer generated so Ca++ channel
resting potential is reached when Na++ to initial position