Muscles - Abdomen, Pelvis, & Shoulder Flashcards
What are the important muscles of the abdomen? (4)
- External Oblique
- Internal Oblique
- Rectus Abdominus
- Transversus Abdominus
What is the Origin of the External Oblique?
- Lower Ribs
What is the Insertion of the External Oblique?
- Linea Alba
What is the Linea Alba?
- A fibrous band that is stretched from the xiphoid process to the pubic symphysis
What is the external oblique aponeurosis?
- A flat sheath of connective tissue that serves as a tendon for the external oblique muscle
What innervates the external oblique muscle?
- The lower intercostal nerves
What is the function of the external oblique muscle?
- Contralateral rotation of the torso
- Compression of the abdominal cavity (increase pressure)
What is the inguinal ligament of the external oblique muscle?
- thickened lower border of the external oblique aponeurosis between the ASIS and the pubic tubercle.
What is the origin and insertion of the Internal Oblique muscle?
Origin
- Iliac Crest and Inguinal Ligaments
Insertion
- Linea Alba via the internal oblique aponeurosis
What innervates the internal oblique muscle? what is its function?
Innervates
- Lower intercostal nerves
Function
- Ipsilateral rotation of the torso
What direction does the Rectus Abdominus run? what is unique about its structure?
Direction
- Vertical up abdomen
Unique
- Divided into smaller chunks by tendinous intersections
What is the origin and insertion points of the Rectus Abdominus?
Origin
- Symphysis Pubis
Insertion
- Xiphoid Process and Nearby Costal Margins
What innervates the Rectus Abdominus? What is its function?
Innervates
- Lower Intercostal Nerves
Function
- Flexion of the trunk as a prime mover
What is the Origin and Insertion points of the Transverse Abdominus muscle?
Origin
- Mainly lower ribs and iliac crest
Insertion
- Linea Alba via transverse abdominus aponeurosis
What Innervates the Transverse Abdominus muscle? What is its function?
Innervation
- Lower intercostal nerves
Function
- Compression of the abdominal cavity