Muscles of the Thorax (Ventral View)

Chapter 7:
The Muscular System:
Name:
Period:
Muscles of the Thorax (Ventral View):
Pectoantebrachialis:
(no human homolog)
Action: rotates forelimb and draws the limb towards chest (adduction)
Origin: manubrium (sternum)
Insertion: fascia of forelimb near elbow
Pectoralis Major:
Action: rotates forelimb and draws the limb towards chest (adduction)
Origin: clavicle, sternum, ris 1-6
Insertion: greater tubercle of the humerus
Pectoralis Minor:
Action: rotates forelimb and draws the limb towards chest (adduction)
Origin: sternum (xiphoid process)
Insertion: proximal half of the humerus
Xiphihumeralis:
(no human homolog)
Action: rotates forelimb and draws the limb towards chest (adduction)
Origin: sternum (xiphoid process)
Insertion:by narrow tendon near proximal end of humerus
Muscles of the Abdomen (ventral view):
Latissimus dorsi:
Action: pulls forelimb dorsocaudally
Origin: last 6 thoracic vertebrae, all lumbar vertebrae and iliac crest
Insertion: intertubercular groove- humerus
External obliques:
Paired superficial muscles that make up the lateral walls of the abdomen
Action: trunk movement- flexion, ab compression, lateral rotation
Origin: lower ribs
Insertion: iliac crest
Rectus abdominus:
Most superficial muscles of the abdomen; largest muscle of the abdomen
Action: flex the vertebral column
Origin: pubis
Insertion: xiphoid process, rib cage
Muscles of the Thorax:
1. pectoantebrachial
is
2. pectoralis major
3. pectoralis minor
4. xiphihumeralis
Muscles of the
Abdomen:
5. latissimus dorsi
6. external obliques
7. rectus abdominus