Muscle Name Description Action Origin Insertion
Pectoralis Major Broad, fan shaped Adducts the foreleg Sternum Humerus of the foreleg
(moves it towards the
Pectoralis Minor Smaller muscle in Adducts and retracts Sternum Proximal end of the
humans. Posterior the foreleg humerus
and deeper to the
Latissimus Dorsi Found near the Moves foreleg caudally - dorsal, lateral and Run anteriorly and
armpits of the pig and dorsally ventral sides of the pig insert on the proximal
- lumbodorsal fascia end of the humerus on
(aponeurosis= sheet of its medial surface
connective tissue in the
area of the lower back)
- lumbar and lower
Linea Alba (not a Center of the ventral
muscle) abdomen. Thickening
of the central part of
“alba”= white (albino) the ventral
like fusion of
Following 4 muscles= abdominal muscles= aid in support of abdominal organs by compressing the abdominal wall + flexing
the trunk. “Huff and puff” muscles. Exercised heavily in sit ups.
**Look for obliques near legs away from midline. NOT found in every abdominal area.
External Oblique Thin sheet of muscle. - posterior ribs -ventral aponeurosis
Fibers run caudo- - lumbodorsal near the linea alba
ventrally (from head fascia they run in both a
caudal and ventral
direction) in an
Internal Oblique Right under the - posterior ribs -ventral aponeurosis
external oblique. - lumbodorsal fascia near the linea alba
Fibers run caudo-
those of the external.
Transverse Abdominus Deep to internal
oblique. Fibers run
right to left, across
the abdominal wall.
Others run almost
parallel to the
Rectus Abdominus Covered by very -pubis -sternum, upper ribs
tough fascia layer
that needs to be
removed to see the
External Intercostals Superficial to internal Raise rib cage during
intercostals. Caudo- inhalation.
Located btwn ribs,
towards the back.
Cover only dorsal
portion of the ribcage.
May need to remove
fibers of latissmus
Internal Intercostals Caudo-dorsal Lower the rib cage
direction. Found during expiration.