Lecture 7 Flashcards
(27 cards)
What are the functions of the muscles in the abdominal wall?
- Protects the internal organs
- Contributes to maintain rect posture
- helps expiration of the lungs
Abdominal muscles from superficial to deep:
- External abdominal oblique
- Internal abdominal oblique
- Rectus abdominis
- Transversus abdominis
What are the key surface anatomy feature of the anterolateral abdominal wall:
- Rectus Sheath
- Linea Alba
Rectus Sheath
- Fascial sheath containing the rectus abdominis muscle
- Runs from pubic symphysis and crests to the xiphoid process and fifth to seventh costal cartilages
Linea Alba
- White line, avascular midline subcutaneous band of fibrous tissue
External Obliques
Largest most superficial of the 4
Origin = External surface of inferior borders of the lower 8 ribs
Insertion = Anterior 1/2 of illiac crest, xiphoid process, linea alba, pubic cres and the pubic tubercle
Functions = Unilateral - Ipsilateral flexion of trunk
Bilateral - Flexes trunk anterolaterlaly
Internal Oblique
- Fibres runs perpendicular to the external oblique
Origin = Thoracolumbar facia, anterior iliac cres, and inguinal ligament
Insertions = Inferior border of the 10-12th ribs and linea alba
Functions = Accessory muscle of respiration and rotates and flex the trunk
Rectus abdominis
Origin = Superior surface of pubic near symohysis
Insertion = Xiphoid process of sternum, inferior surface of ribs 5-7
Actions = Flexes trunk, compresses abdominal wall
Transversus Abdominis
Deepest abdominal muscle
Origin = Deep surface of the lower 6 costal cartilages, lumbar fascia, anterior 2/3 of iliac crest and lateral 1/3 of inguinal ligament
Insertion = Xiphoid process, linea alba, symphysis pubis
Function = Stabilizes lumbar spine and pelvis before movement of the lower and upper limbs
Diaphragm
- A musculotendinous structure is located in the trunk
- Unpaired, dome shaped skeletal muscle that is located in the trunk
- Contraction facilitates expansion of thoracic cavity
Diaphragm
Origin = Xiphoid, Internal surface ribs 7-12 and medial & lateral arcuate ligaments, body of L1-L3 and ALL
Insertion = Central tendon diaphragm
Diaphragm Openings
- Caval opening (vena caval foramen)
- Oesophageal hiatus
- Aortic hiatus
Posterior Abdomen - Lumbar Region
- Lumbar intertransversarii
- Interspinales lumborum intertransversarii
- Multifidus
- Quadratus Lumborum
Iliopsoas Muscles
- Psoas Major
- Psoas Minor
Psoas Minor
Origin = Vertebrae and intervertebral discs of T12-L1
Inserts = Iliopectineal arch
Actions = Flexion, lateral flexion and upward rotation of pelvis
Latissimus Dorsi
Origin = Inferior angle of scapula, ribs 9-12, SP T7-12 and thoracolumbar fascia
Insertion = Intertubercular groove of the humerus
Action = Movement of the arm
Quadratus Lumborum
Origin = Posterior aspect of iliac crest and iliolumbar ligament
Insertion = 12th rib and TP of L1-L4
Functions = Bends trunk, aids in respiration
Multifidus
Origin = Sacrum and TP C2-L5
Insertion = SP of superior vertebrae
Actions = Extension, lateral flexion and contralateral rotation
Erector Spinae Muscles of Lumbar
- Longissimus Thoracic
- Iliocostalis Lumborum
Longissimus Thoracis
Origin = Sacrum, iliac crests, SP L1-L5 and TP of lower Tx
Insertion = TP of T1-L5 and tubercles and angles of lowest 9 or 10 ribs
Action = Erect and laterally flexes the spine when it acts unilaterally
Iliocostalis Lumborum
Origin = Sacrum and iliac crest
Insertion = TP upper Lx, ribs 6-12 and thoracolumbar fascia
Action = extension, abduction and rotation
Muscles of pelvic floor
- Levator ani
- Coccygeus
What is levator ani made up of?
- Puborectalis
- Pubococcygeus
- Iliococcygeus
Puborectalis
Origin = Posterior surface of bodies of pubic bones
Insertion = None
Actions = Draws the distal rectum forward and superiorly, aids in voluntary retention of feces
