Muscles of the Thorax Flashcards
Epaxial
dorsal to the transverse processes of vertebrae
Hypaxial
ventral to the transverse processes of vertebrae
Systems of Epaxial Muscles
transversospinalis, longissumus, iliocostalis
Transversospinalis Muscle System
closest to midline (touching spinous process of vertebrae). From skull to ilium
Longissimus Muscle System
from skull to ilium
Iliocostalis Muscle System
from first rib to ilium, most lateral
Action of the Epaxial Muscles
to extend vertebral column or flex it laterally
Muscles of Respiration
scalenus, serratus dorsalis cranialis, external intercostals, internal intercostals, serratus dorsalis caudalis
Muscles of Inspiration
scalenus, serratus dorsalis cranialis, external intercostals
Muscles of Expiration
internal intercostals, serratus dorsalis caudalis
Scalenus
attached to transverse processes of cervical vertebrae and first few ribs. Pull first few ribs cranially
Serratus Dorsalis Cranialis
attached from dorsal raphe to proximal aspects of ribs 1-10, pull ribs cranially and dorsally
External Intercostal Muscles
run between adjacent ribs caudal-ventral
Internal Intercostal Muscles
run between adjacent ribs cranial-ventral
Action of Internal and External Intercostals
work together to freeze the ribs into one unit
