Exam 2 Flashcards
diaphragm
principle muscle for inspiration
diaphragm origin
lower perimeter of rib cage (ribs 7-11), xiphoid process of sternum, body and transverse processes of upper four lumbar vertebrae, rising to an elevated central tendon.
diaphragm insertion
central tendon.
diaphragm action
flattens, drives central tendon inferiorly, inhalation. increase the volume of thorax and thus create inward air flows and negative pressure
changes. inspiration action.
external intercostals
superior attachment is nearer the vertebral end than the inferior attachment. (angled appearance allows ribs to be raised)
external intercostals origin
superficial inferior margin of ribs 1 - 11
external intercostals insertion
superficial superior margin of rib below.
external intercostals action
raise the ribs
- result is a superior and anterior movement of ventral ribs and sternum
- results in an increase in total lung volume
- contraction moves ribs to a more horizontal position, like blinds
Internal Intercostals Interchondral
lie deep to externals
Internal Intercostals Interchondral origin
deep inferior margin of ribs 1 – 11 within the
region of the costal cartilages.
Internal Intercostals Interchondral insertion
deep superior margin of rib below.
Internal Intercostals Interchondral action
muscle exerts upward pull to raise the ribs.
Levator Costarum origin
transverse process of C7-T11.
Levator costarum insertion
Course downward into sub-adjacent rib.
Levator Costarum action
Slight elevation of posterior rib cage.
serratus posterior superior origin
Spinous Process C7-T3
serratus posterior superior insertion
Courses own to insert into angle of ribs 2-5.
serratus posterior superior action
Elevate ribs 2-5.
Thoracic muscles of expiration
cause a decrease of lung volume that basically moves air out
Transversus Thoracis
on the underside of rib cage
Transversus Thoracis origin
deep surface of the sternum
Transversus Thoracis insertion
costal cartilages above its point of origin
Transversus Thoracis action
lowering of costal cartilages 2 through 6
serratus posterior inferior origin
spinous processes of T10-12 and L1-3.
serratus posterior inferior insertion
attaches to inferior borders of lowest four ribs just beyond angles.
serratus posterior inferior action
rib lowering to help expiration.
Internal Intercostal Interosseous
Lie deep to the external intercostals.
– Oblique orientation.
– Superior attachment is more distant from vertebral end than inferior attachment.
antagonist of external group. its origin is more anterior position than its insertion
Internal Intercostal Interosseous origin
inferior margin of ribs 1 through 11.
Internal Intercostal Interosseous insertion
superior margin of rib below.
Internal Intercostal Interosseous action
depress and lower ribs 1 through 11.
Quadratus Lumborum
orientation is straight up and down – vertical
Quadratus Lumborum origin
posterior half of iliac
Quadratus Lumborum insertion
transverse process of upper lumbar vertebrae and inferior edge of 12th rib.
Quadratus Lumborum action
downward pull on 12th rib (exhalation) or more likely postural control of lower thorax and assisting in abdominal compression
activities.
Latissimus Dorsi
accessory muscle, broad and powerful, convergent into humerus, operates as a stabilizer to stabilize back, scapula, and pelvis.
Latissimus Dorsi origin
spinous processes of the lower thoracic, lumbar & sacral vert, & lumbodorsal fascia.
Latissimus Dorsi insertion
humerus
Latissimus Dorsi action
if lats contract as a unit, compresses posterior abdominal wall and assisting expiration.
External Abdominal Oblique origin
abdominal aponerurosis lateral to rectus abd, linea alba, lateral half of inguinal ligament, anterior half of iliac crest.
External Abdominal Oblique insertion
inferior borders and lower 7-8 ribs.
External Abdominal Oblique action
Lowers ribs and antagonistic to diaphragm. Also compresses front and sides of abdom inward.
External Abdominal Oblique aponeurosis
sheet-like linea abla (tough)
Internal Abdominal Oblique origin
lateral half of inguinal ligament, anterior 2/3 of iliac crest, and lower part of lumbodorsal fascia.
Internal Abdominal Oblique insertion
lowest borders of costal cartilages and abd. aponeurosis lateral to rectus abd.