Muscles of Body Flashcards
The attachment of a muscle on a movable bone.
Insertion
The fixed or immovable point of attachment of a muscle.
Origin
The muscle that supplies the major force for producing a specific movement.
Prime mover (agonist)
A muscle that helps the prime mover.
Synergist
A muscle that opposes the prime mover.
Antagonist
A synergist that immobilizes a bone or a muscle’s origin.
Fixator
A straplike muscle in which the long axes of the fascicles travel along the long axis of the muscle and the muscle fibers extend from the origin to the insertion .
Parallel
Similar to #1 except the muscle has an expanded belly in the middle.
Fusiform
The fascicles are arranged in concentric rings surrounding a body opening .
Circular
The origin of the muscle is broad and the fascicles attach on a single tendon.
Convergent
The fascicles are short and insert obliquely on one side of a tendon.
Unipennate
Similar to #5 except the fascicles insert on both sides of a central tendon.
Bipennate
Similar to #6 except the fascicles insert into multiple small tendons that merge to form one large tendon.
Multipennate
Skeletal muscle fibers can shorten by up to of their resting length as they contract.
1/3
The fascicle arrangement that would allow a muscle to contract the greatest distance is:
parallel
The fascicle arrangement that would give a muscle the greatest contraction strength is:
multipennate
Which factor determines the strength of a muscle’s contractions?
total number of muscle fibers
Orbicularis oculi
Closes eye
Squinting your eyes like you don’t believe me.
Origin: Frontal and maxillary bones
Insertion: Tissue of eyelid
Orbicularis oris
Closes and purses lips
Puckering up your lips to give someone a big smooch.
Origin: Maxilla and mandible
Insertion: Angles of mouth
Masseter
Temporalis
Elevates mandible (two muscles)
Biting down hard on something.
Masseter:
Origin: Zygomatic arch
Insertion: Ramus of mandible
Temporalis:
Origin: Temporal fossa
Insertion: Coronoid process of mandible
Frontalis (frontal belly of epicranius)
Wrinkles forehead and elevates eyebrows
Raising your eyebrows when you are surprised.
Origin: Galea aponeurotica
Insertion: Skin of eyebrows
Sternocleidomastoid
Turns head to side, flexes head and neck
Bending your head down, like when praying.
Origin: Sternum & clavicle
Insertion: Mastoid process of temporal bone
Trapezius
Elevates scapula and draws head back
Pulling your head back, like to look up and ask “Why me?”
Origin: Midsagittal head, neck and back
Insertion: Clavicle and spine of scapula
Pectoralis major
Flexes shoulder and adducts arm
Moving your arm in front of your body, like when pointing to something.
Origin: Clavicle and sternum
Insertion: Greater tubercle of humerus
Latissimus dorsi
Extends shoulder and adducts arm
Pulling the arms behind the body, like when doing the breast stroke.
Origin: Iliac crest, lower thoracic and lumbar vertebrae
Insertion: Intertubercular groove of humerus
Biceps brachii
Flexes elbow and supinates forearm and hand
Bending the elbow to show off your arm muscles like Popeye.
Origins: Coracoid process and above glenoid cavity of scapula
Insertion: Radial tuberosity
Triceps brachii
Extends elbow
Straightening the arm at the elbow.
Origin: Posterior, proximal humerus
and scapula
Insertion: Olecranon process of ulna
Deltoid
Abducts arm, extends or flexes shoulder
Raising your arms up away from the sides of your body, like when pretending to fly.
Origin: Clavicle & spine of scapula
Insertion: Deltoid tuberosity of humerus
Rectus abdominis
Flexes vertebral column
Pulling your trunk up when doing sit ups.
Origin: Top of pubis
Insertion: Bottom of ribcage and sternum
External oblique
Compresses abdomen, lateral rotation of vertebral column
Twisting from side to side at the waist.
Origin: Lower eight ribs
Insertion: Linea alba, top of pubis and ilium
Iliopsoas
Flexes thigh and flexes trunk (as in bowing)
Bending the hip like when taking a bow or when raising your thigh towards your chest.
Origin: Iliac fossa and lumbar vertebrae
Insertion: Lesser trochanter of femur
Gluteus maximus
Extends thigh
Straightening the hip, like when rising from sitting in a chair.
Origin: Ilium, sacrum and coccyx
Insertion: Below greater trochanter of femur
Quadriceps group
Extends leg at knee
(Quadriceps Femoris groups) Straightening the leg at the knee, like to kick a ball.
Origin: Four heads on anterior ilium and superior femur
Insertion: All insert on patella and tibial tuberosity via patellar ligament
Hamstring group
Flexes leg at knee
Bending the knee, like when you are preparing to kick a ball.
Origin: Ischial tuberosity
Insertion: Medial and lateral condyles of tibia
Sartorius
Flexes hip and knee, abducts thigh, rotates thigh laterally (as when sitting cross-legged)
Moving your legs to sit with your knees out and ankles crossed (“Indian-style”).
Origin: Anterior superior iliac spine
Insertion: Medial condyle of tibia
Tibialis anterior
Dorsiflexes ankle
While standing on the heels, raising the big toe towards the anterior leg.
Origin: Lateral condyle of tibia
Insertion: Inferior surface of foot
Gastrocnemius
Plantar flexes foot
Standing on your toes like a ballerina.
Origin: Lateral and medial condyles of femur
Insertion: Posterior surface of calcaneus
