Trunk Flashcards
External oblique
O: ribs
I: linea alba; coxa
A: compresses abdominal cavity; maintains posture
Internal oblique
O: inguinal ligament; iliac crest
I: ribs and costal cartilage; coxa
A: compresses abdominal cavity; maintains posture
Transverse abdominis
O: inguinal ligament; iliac crest; ribs
I: linea alba; coxa
A: compresses abdominal cavity; maintains posture
Rectus abdominis - covered by an aponeurosis called the rectus sheath; linea alba divides left from right
O: coxa - symphysis pubis
I: rib cage – costal cartilage and xiphoid process
A: compresses abdominal cavity; flexes vertebral column (as in leaning forward)
Serratus anterior
O: ribs
I: medial border of scapula
A: abducts and fixes scapula
External intercostals
O: inferior border of a rib
I: superior border of next lower rib
A: elevate ribs when inhaling
Internal intercostals (NOTE: your lab manual has the O and I of these muscles backwards)
O: superior border of a rib
I: inferior border of next higher rib
A: depress ribs when exhaling
Diaphragm
O: rib cage – xiphoid process and lower ribs; vertebrae
I: central tendon
A: inhalation (contraction) and exhalation (relaxation)
Rhomboideus major
O: vertebrae
I: medial border of scapula
A: fixes scapula
Rhomboideus minor
O: vertebrae
I: medial border of scapula
A: fixes scapula
Semispinalis capitis (deep to splenius capitis)
O: vertebrae
I: occipital bone
A: extends head
Other structures/concepts to know
o Linea alba
o Rectus sheath
o Inguinal ligament
One last structure - name origin & insertion
O: skull and sacrum
I: vertebrae and ribs
A: extends and rotates vertebral column
