Lab 5 Flashcards
Prime movers (agonists)
Responsible for producing a particular movement
Antagonists
Oppose or reverse a movement; relaxed when prime mover is active
Synergists
Aid agonists by assisting with the same movement or by reducing unnecessary/undesirable movement
Fixators
Specialized synergists that immobilize the origin of a prime mover so all tension is exerted at insertion
ex: posture muscles
How do muscles of facial expression differ from skeletal muscles
Their insertion is on skin or other muscles rather than bones
What do trunk muscles move
Vertebral column, ribs, head, arms, abdomen
What do upper limb muscles move
arm, forearm, and hands/fingers
What do lower limb muscles move
hip, knee, ankle
Difference between shoulder and pelvic girdle
pelvic girdle needs no extra muscles to stabilize it vs the scapula that needs many to stabilize
Naming skeletal muscles characteristics
Direction of muscle fibers, location of muscle, number or origins, location of muscle origin and insertion, shape of muscle, action of muscle, muscle size
Directional terms of fibers
Rectus- straight (parallel) along midline
Transverse- across midline
Oblique- angled compared to midline
Muscle size terms
Maximus (largest)
Minimus (Smallest)
Longus (long)
Brevis (short)
Origin
Stationary, immovable anchor of muscle
Insertion
Moveable attachment
Innervation
Group of nerves that stimulate a muscle facilitating contraction; trigger contraction
Action of muscle
A muscle can contract or relax and when it contracts an action is produced; allows for motion and joint rotation; action depends on the origin, insertion, and the fiber type arrangement
Typical shapes of muscles
Circular, convergent, parallel, unipennate, bipennate, fusiform, multipennate
Epicranius Occipital Belly
Origin: Occipital and temporal bones
Insertion: Epicranial aponeurosis
Action: Fixes aponeurosis and pulls scalp posteriorly
Epicranius Frontal Belly
Origin: Epicranial aponeurosis
Insertion: Skin of eyebrows, root of nose
Action: Raises eyebrows
Orbicularis Oculi
Origin: Frontal bone, maxilla, and ligaments around orbit
Insertion: Tissue of eyelid
Action: Close eye
Zygomaticus Major
Origin: Zygomatic bone
Insertion: Skin and muscle at corner of mouth
Action: draws angle of mouth laterally and upwards
Zygomaticus Minor
Origin: Zygomatic bone
Insertion: Subcutaneous tissue of lower lip (corner of mouth)
Action: Draws upper lip outward, laterally, and upwards
Orbicularis Oris
Origin: indirectly from maxilla and mandible, fibers blend with fibers of other muscles associated with the lips
Insertion: Encircles mouth, muscle and skin at angles of mouth
Action: close lips
Buccinator
Origin: molar region of maxilla and mandible
Insertion: Orbicularis oris
Action: compresses cheek
Masseter
Origin: Zygomatic arch and bone
Insertion: angle and ramus of Mandible
Action: Prime mover of jaw closure
Temporalis
Origin: Temporal fossa
Insertion: coronoid process of mandible
Action: Close jaw
Platysma
Origin: fascia covering the upper parts of the pectoralis major and deltoid
Insertion: Mandible, skin and muscle at corner of mouth
Action: Tenses skin of neck
Sternohyoid
Origin: Manubrium and medial end of clavicle
Insertion: Lower border of hyoid bone
Action: Depression of hyoid bone, larynx
Sternocleidomastoid
Origin: Manubrium of sternum and medial portion of clavicle
Insertion: Mastoid process of temporal bone and superior nuchal line of occipital bone
Action: flexion of neck, rotate head toward shoulder on opposite side
Scalenes (Anterior, middle, posterior)
Origin: Transverse processes of cervical vertebrae
Insertion: Anterolaterally on ribs 1-2
Action: Elevate ribs 1 and 2
Pectoralis Major
Origin: Clavicle, sternum, cartilage of ribs 1-6 and aponeurosis of external oblique muscles
Insertion: Fibers converge to insert by short tendon into intertubercular sulcus of humerus
Action: Prime mover of arm flexion, adducts medially rotates arm
Serratus Anterior
Origin: ribs 1-9
Insertion: Medial border of scapula
Action: Prime mover to protract and hold scapula against chest wall, rotate scapula
Pectoralis minor
Origin: Anterior surface of ribs 3-5, near their costal cartilages
Insertion: Coracoid process of scapula
Action: With ribs fixed, draws scapula forward and inferiorly
External intercostals
Origin: lower border of ribs above
Insertion: Upper border of ribs below
Action: elevation of ribs
Fibers run like you are putting hands in your pockets
Internal Intercostals
Origin: Superior border of ribs below
Insertion: Inferior border of the ribs above
Action: Depression of the ribs
Diaphragm
Origin: Inferior border of rib and sternum, costal cartilages of last six ribs and lumbar vertebrae
Insertion: Central tendon
Action: Prime mover of inspiration flattens on contraction; expand thoracic, compress abdominal
Rectus Abdominis
Origin: Pubic crest and symphysis
Insertion: Xiphoid process and costal cartilage of ribs 5-7
Action: Flexes and rotates vertebral column
External oblique
Origin: Anterior surface of lower 8 ribs
Insertion: Linea alba, pubic crest and tubercles and iliac crest
Action: Flexes and rotates vertebral column
Fibers run in the direction your hands go in your pockets
Internal oblique
Origin: Lumbar fascia, iliac crest, inguinal ligament
Insertion: linea alba, pubic crest, and costal cartilages of last 3 ribs
Action: flexes and rotates vertebral column, compresses abdominal wall, trunk rotation and lateral flexion
Transverse abdominis
Deepest muscle of abdominal wall
Origin: inguinal ligament, iliac crest, cartilages of the last 5/6 ribs and lumbar fascia
Insertion: Linea alba and pubic crest
Action: Compress abdominal contents.
Trapezius
Origin: Occipital bone, ligamentum nuchae, spines of C7 and all thoracic vertebrae
Insertion: acromion and spinous process of scapula; lateral end of clavicle
Action: Raises, rotates, and retracts (adducts) scapula and stabilizes it
Latissimus dorsi
Origin: indirect attachment to spinous process of lower 6 thoracic vertebrae, lumbar vertebrae, last 3-4 ribs iliac crest
Insertion: Floor of intertubercular sulcus of humerus
Action: Prime mover of arm extension; adducts and medially rotates arm
Levator Scapulae
Origin: Transverse process of C1-C4
Insertion: Medial border of scapula superior to spine
Action: Elevates and adducts scapula
Longissimus
Origin: Transverse process of the upper 4-5 thoracic vertebrae and the articular process of the lower 3-4 cervical vertebrae
Insertion: Posterior margin of the mastoid process, beneath the splenius capitis and sternonucleidomastoid
Action: Extend the head unilaterally, bends the head and turns it to face the same side
Spinalis
Origin: Spinous process of the first 2 lumbar and last 2 thoracic vertebrae
Insertion: spinous process of the upper thoracic vertebrae, 4-8
Action: Extends the head
Iliocostalis
Origin: Iliac crest and lateral portion of the common erector spinae tendon
Insertion: Inferior borders of the angles of the lower six or seven ribs
Action: Extends, laterally flexes, and aids in rotation of the spine, can depress the ribs
Quadratus Lumborum
Origin: Iliac crest and lumbar fascia
Insertion: Inferior border of rib 12, transverse process of lumbar vert
Action: Depresses the 12th rib, flexes lumbar column laterally
Rhomboid major
Origin: Spinous processes of vertebrae T1-T5 (on both sides)
Insertion: Medial vertebral border of scapula
Action: Stabilize scapula
Rhomboid minor
Origin: Spinous process of vertebrae C7-T1 (on both sides)
Insertion: medial border of scapula
Action: stabilization of scapula
