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 Movements

Movements 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