anatomy muscles - block 1

masseter origin

zygomatic arch

masseter insertion

ramus of mandible, coronoid process

masseter innervation

trigeminal nerve

masseter action

elevates mandible, closes jaw

temporal origin

temporal fossa

temporalis insertion

coronoid process, ramus of mandible

temporalis innervation

trigeminal

temporalis action

elevates mandible, closes jaw

digastric origin

anterior: mandible

posterior: temporal bone

digastric insertion

body of hyoid bone

digastric innervation

anterior: trigeminal

posterior: facial

digastric action

opens mouth by lowering mandible

mylohyoid origin

mandible

mylohyoid insertion

body of hyoid bone

mylohyoid innervation

trigeminal

mylohyoid action

elevates hyoid bone, depresses mandible

sternohyoid origin

manubrium, medial end of clavicle

sternohyoid insertion

body of hyoid bone

sternohyoid action

depresses larynx and hyoid bone

sternothyroid origin

manubrium

sternothyroid insertion

thyroid cartilage

sternothyroid action

depresses larynx and thyroid cartilage

sternocleidomastoid origin

sternal head: manubrium

calvicular head: medial third of clavicle

sternocleidomastoid insertion

mastoid process of temporal bone, occipital bone

sternocleidomastoid innervation

accessory nerve

sternocleidomastoid action

bilaterally: flex head

unilaterally: turns face toward opposite side

splenius group origin

spinous processes of inferior cervical vertebra and superior thoracic vertebra

splenius group insertion

mastoid process of temporal bone, occipital bone

splenius group action

extend neck

platysma innervation

facial nerve

platysma action

tenses skin of neck

scalenes action

flex neck, elevate ribs

erector spinae origin

posterior sacrum, iliac crest, spinous processes of lower lumbar and sacral vertebrae

erector spinae action

extends and laterally bends vertebral column and head

iliocostalis group insertion

angles of lower ribs, cervical transverse processes

longissimus insertion

between tubercles / angles of ribs, transverse processes of thoracic and cervical vertebrae, mastoid process

spinalis group insertion

spinous processes of upper thoracic and mid-cervical vertebrae

external intercostals origin

lower border of ribs

external intercostals insertion

upper border of rib below rib of origin

external intercostals innervation

intercostal nerves

external intercostals action

elevates ribs in inspiration

quadratus lumborum origin

iliac crest

quadratus lumborum insertion

transverse processes of lumbar vertebrae

quadratus lumborum action

extends and laterally flexes vertebral column

internal intercostals origin

superior border of ribs

internal intercostals insertion

inferior border of the more superior rib

internal intercostals innervation

intercostal nerves

internal intercostals action

depress ribs

external oblique origin

external surfaces of ribs 5-12

external oblique insertion

linear alba, iliac crest

external oblique innervation

intercostal nerves 5-12

external oblique action

compresses and supports abdominal viscera, flexes and rotates trunk

internal oblique origin

iliac crest

internal oblique insertion

inferior borders of ribs 10-12, linea alba, pubis

internal oblique innervation

intercostal nerves 5-12

internal oblique action

compresses and supports abdominal viscera, flexes and rotates trunk

transversus abdominis origin

internal surfaces of costal cartilages 7-12, iliac crest

transversus abdominis insertion

linea alba, pubic crest

transversus abdominis innervation

intercostal nerves 5-12

transversus abdominis action

compresses and supports abdominal viscera

rectus abdominis origin

pubic symphysis, pubic crest

rectus abdominis insertion

xiphoid process, costal cartilages 5-7

rectus abdominis innervation

thoracic nerves T7-T12

rectus abdominis action

flexes trunk, compresses abdominal viscera

trapezius origin

occipital bone, spinous processes of C7-T12

trapezius insertion

lateral third of clavicle, acromion, spine of scapula

trapezius innervation

accessory nerve

trapezius action

elevates, retracts, and rotates scapula;

lower fibers that depress scapula

levator scapulae origin

transverse process of C1-C4

levator scapulae insertion

medial border of scapula

levator scapulae innervation

C3-C4 and dorsal scapular nerve

levator scapulae action

elevates scapula medially, inferiorly rotates glenoid cavity

rhomboid major origin

spinous processes of T2-T5 vertebrae

rhomboid minor origin

spinous processes of C7 and T1 vertebrae

rhomboid muscles insertion

medial border of scapula

rhomboid muscles innervation

dorsal scapular nerve

rhomboid muscles action

adducts and inferior rotation of scapula

pectoralis minor origin

ribs 3-5

pectoralis minor insertion

coracoid process of scapula

pectorlais minor innervation

medial pectoral nerve

pectoralis minor action

lowers scapula and protracts shoulder

serratus anterior origin

first 9 ribs

serratus anterior insertion

medial border of scapula

serratus anterior innervation

long thoracic nerve

serratus anterior action

protracts shoulder and rotates scapula so glenoid cavity moves superiorly