Muscles (O, I, A) P. 13-14

Question 1

M. obliquus externus abdominis

Answer 1

O: Superf. layer of fascia thoracolumbalis + lateral aspect of ribs 4-12

I: Fibres runs caudoventrally (\) to linea alba
(caudal on pelvis, forms lig. inguinale + creates crus med. et lat. around anulus inguinales superf.)

A: Maintaining abdominal pressure (urination, defecation, parturition) + protection of abdominal organs

Question 2

M. obliquus internus abdominis

Answer 2

O: Superf. layer of fascia thoracolumbalis, tuber coxae and lig. inguinale

I: Fibres runs cranioventrally (///) to linea alba
(at preumbilical site, has an outer and inner layer that envelops M. rectus abdominis)

A: Mainaining abdominal pressure + protection

Question 3

M. transversus abdominis

Answer 3

O: Deep layer of fascia thoracolumbalis, proc. transversus of lumbar vertebrae and medial surface of false ribs

I: Fibres runs tranversely (¦¦¦) to linea alba

A: Maintainting abdominal pressure + protection

Question 4

M. rectus abdominis

Answer 4

O: Cran. from sternum

I: Pecten ossis pubis (together w/ M. pectineus)

A: Maintaining abdominal pressure + protection

Question 5

Rectus sheet

Answer 5

• Formed around M. rectus abdominis
• Muscles contributing: external oblique (E), internal oblique (I), transverse (T), rectus (R), fascia transversa abdominis + peritoneum (P)

- Outer to inner order:
~ Thoracic: E – R – thoracic wall
~ Preumbilical: E–I – R – I – T – P
~ Umbilical: E –I – R – T – P
~Postumbilical: E – I –T – R – P

Question 6

Anulus inguinalis superf.

Answer 6

Bordered by:

> Crus med. et lat. (lamina abdominalis et pelvina), formed by M. obliquus externus abdominis

Question 7

Anulus inguinalis prof.

Answer 7

Bordered by:

> Rostral - M. obliquus internus abdominis
Medial - M. rectus abdominis
Caudal - Lig. inguinale

Question 8

Canalis femoralis

Femoral triangle

Answer 8

Bordered by:

> Rostral - M. sartorius pars caud.
> Caudal - M. pectineus
> Proximal - Lig. inguinale
> Medial - M. iliopsoas
> Lateral - Fascia femoralis

Question 9

M. psoas minor

Answer 9

Mainly tentinous = white!!

O: Corpus vertebrae of last few Th + L1-5

I: Linea arcuata (near eminetia iliopubica)

A:
~ If vertebral column is fixed - draws pelvis to a deeper position
~ When pelvis is fixed - arches lumbar region + flexes vertebral column

Question 10

M. quadratus lumborum

Answer 10

O: Ventrally on Th11-13 + last 2 ribs

I: Medial surface of Ala ossis illi

A: Fixation + dorsal flexion of vertebral column

Question 11

M. iliopsoas

Answer 11

O:
> M. psoas major - ventrally from corpus vertebrae + proc. transversus in lumbar region
> M. iliacus med. et lat. - between linea arcuata and lateral border of iliac bone

I: medially on trochanter minor (femur)

A: Flexes hip + draw pelvic limb forward
~ If femur is fixed - flex + fixates vertebral column