Functional Anatomy - Abdominal (Detailed)

Question 1

State the origin, insertion, isometric, concentric and eccentric functions for the muscle in yellow:

Answer 1

RECTUS ABDOMINIS

ORIGIN
Pubic symphysis of the pelvis

INSERTION
Ribs 5–7

Concentric Action
Spinal flexion, lateral flexion, and rotation

Eccentric Action
Spinal extension, lateral flexion, and rotation

Isometric Action
Stabilizes the lumbo–pelvic–hip complex

INNERVATION
Intercostal nerve T7–T12

Question 2

State the origin, insertion, isometric, concentric and eccentric functions for the muscle in yellow:

Answer 2

EXTERNAL OBLIQUE

ORIGIN
External surface of ribs 4-12

INSERTION
Anterior iliac crest of the pelvis, linea alba, and contralateral rectus sheaths

Concentric Action
Spinal flexion, lateral flexion, and contralateral rotation

Eccentric Action
Spinal extension, lateral flexion and rotation

Isometric Action
Stabilizes the lumbo–pelvic–hip complex

INNERVATION
Intercostal nerves (T8–T12), iliohypogastric (L1), ilioinguinal (L1)

Question 3

State the origin, insertion, isometric, concentric and eccentric functions for the muscle in yellow:

Answer 3

INTERNAL OBLIQUE

ORIGIN
Anterior two-thirds of the iliac crest of the pelvis and thoracolumbar fascia

INSERTION
Ribs 9–12, linea alba, and contralateral rectus sheaths

Concentric Action
Spinal flexion (bilateral), lateral flexion, and ipsilateral rotation

Eccentric Action
Spinal extension, rotation, and lateral flexion

Isometric Action
Stabilizes the lumbo–pelvic–hip complex

INNERVATION
Intercostal nerves (T8–T12), iliohypogastric (L1), ilioinguinal (L1)

Question 4

State the origin, insertion, isometric, concentric and eccentric functions for the muscle in yellow:

Answer 4

TRANSVERSE ABDOMINUS

ORIGIN
Ribs 7–12, anterior two-thirds of the iliac crest of the pelvis and thoracolumbar fascia

INSERTION
Linea alba and contralateral rectus sheaths

Concentric Action
Increases intra-abdominal pressure. Supports the abdominal viscera

Isometric Action
Synergistically with the internal oblique, multifidus, and deep erector spinae to stabilize the lumbo–pelvic–hip complex

INNERVATION
Intercostal nerves (T7–T12), iliohypogastric (L1), ilioinguinal (L1)

Question 5

State the origin, insertion, isometric, concentric and eccentric functions for the muscle in yellow:

Answer 5

DIAPHRAGM

ORIGIN
Costal part: inner surfaces of the cartilages and adjacent bony regions of ribs 6–12. Sternal part: posterior side of the xiphoid process. Crural (lumbar) part: (1) two aponeurotic arches covering the external surfaces of the quadratus lumborum and psoas major; (2) right and left crus, originating from the bodies of L1–L3 and their intervertebral discs

INSERTION
Central tendon

Concentric Action
Pulls the central tendon inferiorly, increasing the volume in the thoracic cavity

Isometric Action
Stabilization of the lumbo–pelvic–hip complex

INNERVATION
Phrenic nerve (C3–C5)