Lab 3 and 4: Integumentary and Muscular Systems
Skeletal Muscleorigin - what muscle attaches to for
leverage, usually larger and more stationary bone than insertion
insertion - what muscle attaches to for movement, usually a smaller bone than the origin and not stationary; the insertion is what the muscle acts upon and causes to move
action - this is the type of movement that occurs
Triceps Brachii – origin = proximal humerus, insertion = proximal ulna, action = elbow extention
Biceps Brachii – origin = lateral scapula, insertion= proximal radius, action = flexes forarm
Helpful hints for identification of skeletal muscles:
Relative to direction of muscle fibers: rectus -fibers running parallel to the midline of the body or longitudinal axis of a bone
transverse - fibers running at right angles or perpendicular to the midline or longitudinal axis of a bone
oblique - fibers running obliquely (slanted or at a diagonal) to the midline of the body or longitudinal axis of a bone
Relative to size:
maximus – largestminimus – smallestlongus – longbrevis - short
Relative to the number of origins:
Biceps – 2
Triceps – 3
Quadriceps – 4
Relative to location of origin and insertion example:
sternohyoid - sterno refers to the origin, which is the manubrium of the sternum and hyoid refers to the insertion, which is the hyoid bone.
Relative to location of muscle example:
brachioradialis - brachio refers to arm and radialis refers to the radius. This muscle runs along the radius of the forearm
Relative to shape of the muscle example:
deltoid - the muscle is triangular like the name implies
Rhomboid
Muscle MovementsMovements that occur in the saggital plane:
flexion/extension - waist (bend/extend)
plantarflexion/dorsiflexion - ankle (point/ bend)Movements that occur in the frontal plane:
abduction/adduction - arm/hip (movement away from midline/movement toward midline)
inversion/eversion - foot (turn or roll foot in/ turn or roll foot out)Movements that occur in the transverse plane:
rotation - neck
pronation/supination - wrist (turn hand palm down/palm upantagonist muscle groups - one muscle works against the other (ex: biceps brachii and
triceps brachii - when one muscle flexes the other extends)elevation/depression - upward movement/
downward movement (shrugging your shoulders)protraction/retraction - moving a part of the body away from the axis /opposite
action (you protract your jaw when you grasp your upper lip with your lower teeth)tensor - makes more rigidsphincter - closes hole
Abdominal Wall Muscles:External obliques
Internal obliques
Transverse Abdominus
Rectus Abdominus "6-pack")
Rotator Cuff Muscles ("SITS") ** ALL rotator cuff muscles: origin=scapula, insertion=humerus
Supraspinatus
Infraspinatus
Teres Minor
Subscapularis
Quadriceps Femoris ("Quads") ** ALL quad muscles: insertion=tibial tuberosity via patellar ligament, action=knee extensionVastus Lateralis
Vastus Medialis
Vastus Intermedius
Rectus Femoris
Hamstrings** ALL hamstring muscles: origin=ischium (the ischial tuberosities you "sit on"), action=knee flexion
Biceps femoris
Semimembranosus
Semitendinosous
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