Week IIII Muscles Flashcards
Diaphragm
O: internal surface of ribs 7-12 and their costal cartilage, internal surface of the xiphoid process of the sternum, and anterior vertebral bodies of L1-L3
I: central tendon (dome) of the diaphragm
A: expands the thoracic cavity when abdominal breathing
External Intercostals
O: inferior boarder of one rib
I: superior boarder of the rib directly inferior
A: elevates the ribs at the sternocostal and costospinal joints (to assist with inhalation)
Internal Intercostals
O: superior boarder of one rib (and its costal cartilage)
I: inferior boarder of the rib (and its costal cartilage) directly superior
A: depresses ribs at the sternocostal and costospinal joints (to assist with exhalation)
Serratus Posterior Superior
O: inferior ligamentum nuchae and spinous processes (SPs) of C7-T3
I: superior external surfaces of ribs 2-5
A: elevate ribs 2-5 (during inhalation) at the sternocostal and costospinal joints
Serratus Posterior Inferior
O: spinous processes of T11-L3
I: inferior external surfaces of ribs 9-12
A: depress ribs 9-12 (in exhalation) at the sternocostal and costospinal joints