Anatomy lab week 10!! (minus neck muscles lmao)

external intercostals action

elevates and protracts ribs, which expands the thoracic cavity

internal intercostals action

aids in forced exhalation, which depresses and retracts ribs, which compresses thoracic cavity

rectus abdominis origin

pubic symphysis and superior margin of pubis

rectus abdominis insertion

xiphoid process and costal cartilage

rectus abdominis action

flexion of trunk

external obliques action

contralateral waist rotation, maintains posture, and stabilizes vertebral column

internal oblique action

ipsilateral waist rotation, maintains posture, and stabilizes vertebral column

transverse abdominis action

compresses abdominal contents

pectoralis major origin

medial 1/3 of clavicle and lateral margin of sternum

pectoralis major insertion

intertubercular sulcus of humerus

pectoralis major action

flexion of shoulder

pectoralis minor origin

ribs 3-5 and overlying fascia

pectoralis minor insertion

coracoid process of scapula

pectoralis minor action

protracts scapula

serratus anterior origin

all ribs

serratus anterior insertion

medial border of scapula

serratus anterior action

prime mover in all forward reaching and pushing actions

diaphragm action

prime mover of inspiration

linea alba

fibrous structure running between xiphoid process and pubic symphysis

semispinalis action

extension of head and neck

iliocostalis action

depresses ribs and extension and lateral flexion of vertebral column

longissimus action

extension of head, depresses ribs, and extension and lateral flexion of vertebral column

spinalis action

extension and lateral flexion of vertebral column

rhomboideus minor action

fixes scapula during arm movement

rhomboideus major action

retracts scapula

latissimus dorsi action

adduction, extension, and medial rotation of shoulder

trapezius origin

medial 1/3 of superial nuchal line, nuchal ligament, and spinous processes of thoracic vertebrae

trapezius insertion

acromion and spine of scapula and lateral 1/3 of clavicle

trapezius action

elevates and depresses shoulder, stabilizes scapula and shoulder during arm movements, and rotates and retracts scapula

levator scapulae action

elevates scapula (when cervical vertebrae are fixed)

temporalis action

elevation of mandible

masseter origin

zygomatic arch

masseter insertion

lateral surface of mandibular ramus and angle

masseter action

elevation of mandible

orbicularis oculi action

closes eye in blinking, squinting, and sleep

levator palpabrae superioris action

elevates upper eyelid

zygomaticus major action

elevates corner of mouth when smiling/laughing

zygomaticus minor action

elevation of upper lip

orbicularis oris action

closes lips

platysma action

draws lower lip and angle of mouth downward in expressions of horror/surprise

sternocleidomastoid action

contralateral rotation of head

scalenes action

neck flexion