Chapter 11 Flashcards
Origin
Less movable attachment of a muscle; proximal attachment
Insertion
More movable attachment of a muscle; Distal attachment
Axial Muscles
Origins and insertions of axial skeleton; support and move the head and vertebral column; function in non-verbal communication; aid breathing; support and protect the abdominal and pelvic organs
Appendicular Muscles
Control movements of upper and lower limbs; control movements of pectoral and pelvic girdles; organized into groups based on locations
Patterns of fascicle arrangement
Circular, parallel, convergent; pennate
Primary Actions
Agonist, antagonist, Synergist
Agonist
prime mover, muscle that contracts to produce a movement
Antagonist
muscle whose contraction opposes that of the agonist
Synergist
muscle that assists agonist by contributing tension or stabilizing point of origin
Naming criteria for skeletal muscles
Muscle action, Specific body regions, muscle attachments; orientation of muscle fibers; Muscle shape, muscle size, number of muscle heads at an attachment site
Pronator Teres and Pronator quadratus
rotate the radius across the ulna to pronate forearm
Supinator
supinates forearm
Triceps brachii
helps extend and adduct the arm
Anconeus
Weak elbow extensor, crosses posterolateral region of elbow
Biceps brachii
assists in flexing the arm
Brachialis
Most powerful flexor of the forearm; deep to biceps brachii
Brachioradialis
located on anterolateral forearm; Synergist in elbow flexion
Latissimus dorsi
broad triangular muscle on back; prime arm extensor;
Pectoralis Major
Thick fan-shaped muscle on superior, anterior thorax; prime arm flexor
Deltoid
Prime abductor of the arm; anterior fibers flex and medially rotate arm; lateral fibers abduct the arm; posterior fibers extend and laterally rotate arm
Croacobrachialis
Flexes and adducts the arm
Teres Major
Extends, adducts, medially rotates arm
Rotator Cuff
includes subscapularis, supraspinatus, infraspinatus, teres minor
Sternocleidomastoid
Extends from sternum and clavicle to mastoid; turns head
Scalenes
lateral flexion of neck
Splenius capitis and cervicus
When contracted unilaterally turn head to same side
Trapezius
primary function is to help move pectoral girdle, but also helps extend neck
Levator Scapulae
elevates and inferiorly rotates the scapula
Quadriceps Femoris
Composite muscle with four heads; prime mover of knee extension;
Satorius
Flexes and laterally and medially rotates the thigh
Gracilis
Flexes the leg and adducts the thigh
Biceps femoris
Two heads; laterally rotates the leg when leg is flexed
Semitendinosus
Medially rotate leg when leg is flexed
Sternocleidomastoid
bilateral contraction flexes neck, unilateral contraction causes lateral flexion of head to contractive muscle’s side and rotation of head to opposite side
Scalenes
Anterior, middle, and posterior, work to flex neck, pull cervical vertebrae toward 1st and 2nd ribs (lateral flexion of neck); elevate 1st and 2nd ribs during forced inhalation
Splenius capitis & cervicus
When contracted bilaterally, extend neck; when contracted unilaterally, turn head to same side
Trapezius
Can elevate, depress, retract, or rotate scapula
Levator scapulae
Elevates and inferiorly rotates the scapula
Erector spinae (lateral to medial)
Iliocostalis, longissimus, spinalis
Semispinalis Group (capitis & cervices)
when contracted bilaterally, extend neck, when contracted unilaterally, turn head to same side
