Muscles of the trunk Flashcards
Origin of external intercostal muscles
Inferior margin of ribs.
Insertion of external intercostal muscles
Superior margin of ribs below
Action of external intercostal muscles
Elevate ribs during forced inspiration
Innervation of external intercostal muscles
Anterior rami of T1-T11
Origin of internal intercostal muscles
Superior margin of ribs below.
Insertion of internal intercostal muscles
Inferior lateral edge of costal grooves above
Action of internal intercostal muscles
Depresses ribs during forced expiration
Innervation of internal intercostal muscles
Anterior rami of T1-T11
Origin of innermost intercostal muscles
Deep surface of ribs below
Insertion of innermost intercostal muscles
Medial edge of costal grooves
Action of innermost intercostal muscles
Depresses ribs during forced expiration
Innervation of innermost intercostal muscles
Anterior rami of T1-T11
Origin of transversus thoracic muscles
Posterior aspect of xiphoid process, inferior aspect of sternum, adjacent costal cartilages of lower true ribs.
Insertion of transversus thoracic muscles
Lower border of costal cartilages of Rib 3-6
Action of transversus thoracic muscles
Depresses costal cartilages. Active during forced respiration.
Innervation of transversus thoracic muscles
Anterior rami of T1-T11
Origin of psoas major muscle
Body, Intervertebral discs and Transverse processes of T12, L1-L5
Insertion of psoas major muscle
Lesser trochanter of Femur
Action of psoas major muscle
Flexes thigh at hip joint when trunk stabilized, flexes trunk when body is supine.
Innervation of psoas major muscle
Anterior rami of L1-L3
Origin of psoas minor muscle
Body of T12 and L1
Insertion of psoas minor muscle
Pectineal line and Iliopubic eminence
Innervation of psoas minor muscle
Anterior rami of L1
Action of psoas minor muscle
Weak flexor of lumbar vertebral column
Origin of quadratus lamborum
Transverse process of L5, Iliac Crest, Iliolumbar process
Insertion of quadratus lamborum
Transverse processes of L1-L4, Inferior border of rib 12
Innervation of quadratus lamborum
Anterior rami of T12, L1-L4.
Action of quadratus lamborum
Depresses and stabilizes Rib 12, lateral bending of trunk, both muscles together extend trunk
Origin of iliacus muscle
Iliac fossa.
Insertion of iliacus muscle
Joins with Psoas major to insert on lesser trochanter of Femur
Innervation of iliacus muscle
Femoral nerve.
Action of iliacus muscle
Flexes thigh at hip joint and flexes trunk when supine
Origin of external oblique
Lower six rib shafts (T7-T12).
Insertion of external oblique
Linea alba, pubic tubercle.
Innervation of external oblique
Thoracoabdominal nerves (T7-T11 anterior rami).
Action of external oblique
Flexion of torso
Origin of internal oblique
Inguinal ligament, iliac crest.
Insertion of internal oblique
Linea alba, Ribs 10-12.
Innervation of internal oblique
Thoracoabdominal nerves (T7-T11 anterior rami) and Subcostal nerve.
Action of internal oblique
Flexion of trunk
Origin of transversalis abdominus muscle
Thoracolumbar fascia, iliac crest, inguinal ligament and costal cartilages of lower 6 ribs
Insertion of transversalis abdominus muscle
Linea alba, Pubic crest, Pectineal line.
Innervation of transversalis abdominus muscle
Thoracoabdominal nerves (T7-T11 anterior rami) and Subcostal nerve.
Action of transversalis abdominus muscle
Compresses abdominal contents
Origin of rectus abdominus muscle
Pubic crest and Pubic symphysis
Insertion of rectus abdominus muscle
Costal cartilages of Rib 5-7, and xiphoid process
Innervation of rectus abdominus muscle
Thoracoabdominal nerves (T7-T11 anterior rami) and Subcostal nerve.
Action of rectus abdominus muscle
Compresses abdominal contents, flexes vertebral column and tenses abdominal wall.
Origin of pyramidalis muscle
Pubis and Pubic symphysis.
Insertion of pyramidalis muscle
Linea alba
Innervation of pyramidalis muscle
Subcostal nerve