most skeletal muscles
extend from one bone to another and cross at least one joint
some facial muscles
attach to bone and the connective tissue of the skin
tendons
attach muscles to bones and to other muscles - type of dense fibrous connective tissue
aponeurosis
broad, flat expanse of tendon
synergists
groups of muscles working together to cause movement
prime mover
one muscle in a group that accomplishes the major desired movement
antagonists
groups or individual muscles working in opposition to one another
location, size, shape, orientation, origin and insertion, number of heads, function
ways to name muscle
flexion
bringing two ventral surfaces close together
extension
moving two primary ventral surfaces farther apart
dorsiflexion
bringing the toes towards the shin
plantar flexion
flexion of the foot (curling of the toes)
abduction
movement of a limb away from the midline
adduction
movement of a limb toward the midline
circumduction
the distal end of a bone describes a circle while the proximal end stays stationary
pronation
make the palm face the posterior in anatomical position
supination
make the palm face the anterior in anatomical position
inversion
turning the sole of the foot medially at ankle
eversion
turning the sole of foot laterally at the ankle
protraction
moving the mandible or clavicle anteriorly in a plane that is parallel to the ground
retraction
moving the mandible or clavicle posteriorly in a place that is parallel with the ground
elevation
movement in a superior direction
depression
movement in an inferior direction
frontalis
Origin: epicranial aponeurosis
Insertion: skin of forhead and eyebrows
Action: elevates eyebrows and scalp
orbicularis oculi
Origin: Medial margin of orbit
Insertion: Skin around eyelids
Action: Closes eye
zygomaticus minor
Origin: zygomatic bone
Insertion: orbicularis oris muscle
Action: elevates upper lip
zygomaticus major
Origin: zygomatic bone
Insertion: corner of the mouth
Action: draws corner of the mouth
platysma
Origin- Fascia in upper chest
Insertion- Lower border of mandible
Action- Draws angle of mouth downward
orbicularis oris
origin: maxillary bone and mandible
insertion: lips
action: compresses, purses lips
buccinator
origin: molar region of maxilla and mandible
insertion: orbicularis oris
action: compresses cheek
corrugated supercilii
origin: arch of frontal bone above nasal bone
insertion: skin of eyebrow
action: draws eyebrows medially and inferiorly
temporalis
origin: temporal fossa
insertion: coronoid process of mandible
action: closes jaw
masseter
Origin: zygomatic arch
Insertion: mandible
Action: elevates mandible
Sternocleidomastoid (SCM)
origin: clavicle, sternum
insertion: mastoid process of temporal bone
action: flex and rotate head
**contract right turns head to left and vice versa
scalenes
Origin: ribs
Insertion: cervical vertebrae pleurapophyses
Action: flexes neck
serratus anterior
-Origin: fleshy slips from the outer surface of upper 8 or 9 ribs
-Insertion: costal aspect of medial margin of the scapula
-
Actions
: protracts and stabilizes scapula, assists in upward rotation.
pectoralis major
-Origin: Clavicular head, Sternocostal head
-Insertion: Lateral lip of the bicipital groove of the humerus
(anteromedial proximal humerus)
-Actions: flexes the humerus*
pectoralis minor
Origin: sternum
Insertion: humerus
Action: adducts forelimb
diaphragm
Large, flat muscle at the bottom of the chest cavity that helps with breathing - breathe in is active, breathe out is passive
intercostals
muscles between the ribs
rectus sheath
Fibrous sleeve enclosing the rectus abdominis
external oblique
Origin: lumbodorsal fascia and ribs
Insertion: linea alba and pubis
Action: constricts abdomen
rectus abdominus
Origin: pubic crest and symphysis
Insertion: xiphoid process and costal cartilages of ribs 5-7
Action: flexes and rotates vertebral column
linea alba
midline tendinous seam joining the abdominal muscles
internal obliques
Origin: iliac crest, inguinal ligament and lumbar fascia
Insertion: 10th to 12th ribs and rectus sheath
Action: flexes and rotates vertebral column, compresses abdomen and depresses thorax
transversus abdominis
Origin: costal ribs
Insertion: linea alba
Action: compresses abdomen
trapezius
-Origin: spinous processes of vertebrae C1-T12
-Insertion external occipital protuberance, nuchal ligament, medial superior nuchal line, posterior border of the lateral third of the clavicle, acromion process, and spine of scapula
-
Actions
rotation, retr
latissimus dorsi
origin: lower spine and iliac crest
insertion: proximal humerus
action: extends and adducts humerus
splenius capitis
Origin: Spinous processes of C7-T6
Insertion: Mastoid process and occipital bone
Action: Extends head; rotates head
levator scapulae
origin: transverse processes of C1-C4
insertion: medial border of scapula superior to spine
action: elevates and adducts scapula
rhomboid minor
origin: spines of thoracic vertebrae
insertion: vertebral border of scapula
action: pulls scapula back and medial
rhomboid major
Origin:
Spines of T2-T5
Insertion:
Medial border of scapula inferior
to spine
Action:
Elevation, retraction and downward
rotation of the scapula
semispinalis capitis
Origin: Transverse processes of C7-T12
Insertion: Occipital bone
Action: Extends vertebral column
erector spinae group
iliocostalis, longissimus, spinalis
spinalis group
Origin: Vertebrae
Insertion: Vertebrae
Action: Extend Neck
longissimus group
Origin: Vertebrae
Insertion: Vertebrae
Action: Extend Neck
iliocostalis group
Origin: Superior borders of ribs and iliac crest
Insertion: Transverse processes of cervical vertebrae and inferior surfaces of ribs
Action: Extends vertebral column or laterally to that side; moves ribs