Abdomen wk 1 Flashcards
(47 cards)
Origin of External Oblique Muscle
The lower 8 ribs (V-XII)
Describe the arrangement of the dermatomes of the abdomen.
The skin in the right and left hypochondriac regions are innervated by T7-T9 lat and ant cutaneous branches
The skin over the umbilicus is innervated by T10
The skin of the inguinal region is innervated by L1 via the iliohypogastric and ilioinguinal nerves
Insertion of External Oblique Muscle
Linea alba
Lateral lip of iliac crest
Innervation of External Oblique
Thoracoabdominal nerves (T7-T11/T12) and sometimes Subcostal nerve
Main Action of External Oblique Muscle
Compresses abdominal contents
Flexes the trunk
Bends the trunk to the same side
Turns the ant abdomen to the opposite side
Origin of Internal Oblique Muscle
Intermediate Zone of iliac crest
Thoracolumbar fascia
Lat 1/2 of inguinal ligament
Insertion of Internal Oblique Muscle
Linea alba
Lower 3-4 ribs
Pubic Crest
Conjoint tendon/pecten pubis
Innervation of Internal Oblique Muscle
Anterior rami or Lower 6 thoracic spinal nerves T7-T12, L1
Main Action of Internal Oblique
Compresses abdominal contents
Flexes the trunk
Bends the trunk to the same side
Turns the trunk to the same side
Origin of Transversus Abdominis
Medial lip of iliac crest
Thoracolumbar fascia
Lat 1/3 of inguinal ligament
Lower 6 Costal cartilages
Insertion of Transversus Abdominis Muscle
Linea alba
Conjoint tendon
Pubic crest
Innervation of Tranversus Abdominis Muscle
T7-T12, L1
Main Action of Transversus Abdominis Muscle
Compresses abdominal contents
Origin of Rectus Abdominis Muscle
Pubic Crest, Pubic Tubercle, Pubic Symphysis
Insertion of Rectus Abdominis Muscle
Xiphoid process, V-VII costal cartilages
Innervation of Rectus Abdominis Muscle
T7-T12
Main Action of Rectus Abdominis Muscle
Compresses abdominal contents
Flexes the vertebral column
Tenses the abdominal wall
Origin of Pyramidalis Muscle
Front of pubis, pubic symphysis
Insertion of Pyramidalis Muscle
Linea alba
Innervation of Pyramidalis Muscle
Subcostal nerve (T12)
Main Action of Pyramidalis Muscle
Tenses linea alba
What is the combined functions of the anterolateral muscles of the abdominal wall
Move the trunk and maintain posture
Depress ribs during expiration
Support and protect viscera
Compress abdomen
Describe The rectus sheath
The strong, incomplet fibrous compartment of the rectus abdominis and pyramidalis mm & neurovascular structures
It is formed by the aponeurosis of External Oblique, Internal Oblique and transversus abdominus.
At approximately 1/3 the distance between the umbilicus and the pubic crest there is a line known as the arcuate line
Above the arcuate line the rectus sheath has posterior and anterior compartments but bellow it, it has only anterior
Boundaries of the Rectus Sheath
Above the umbilicus:
Ant: External Oblique Muscle
Post: Xiphoid process, 6th & 7th costal cartilages.
At the umbilicus:
Ant: External Oblique m, ant layer of Internal Oblique.
Post: post layer of Internal Oblique, Transversus Abdominis
At arcuate line:
Ant: external & internal oblique, Transversus Abdominis
Post: Transversalis fascia