Thorax and Abdomen

Question 1

External Oblique

Answer 1

Origin: Ribs 7-12 (Lower 8 ribs)

Insertion: 
Xiphoid process
Linea Alba
Pubic Tubercle 
Pubic crest
Iliac Crest

Nerve Supply: Lower 6 Thoracic Nerves (T7-T12)
Iliohypogastric (T12-L1)& Ilioinguinal (L1)

Action: Supports abdominal contents;

1) assists in flexing & rotation of trunk
2) assist in forced expiration
3) micturition
4) defecation
5) parturition (child labor)
6) vomiting

Question 2

Internal Oblique

Answer 2

Origin: Lumbar Fascia
Iliac crest
Lateral ⅔ of the Inguinal ligament (connects the ilium to the pubis)

Insertion: 
Lower 3 Ribs & costal cartilage
Xiphoid process
Linea Alba
Symphysis Pubis

Nerve Supply:
Lower 6 Thoracic Nerves (T7-T12)
Iliohypogastric (T12-L1)& Ilioinguinal (L1)

Action: 
Supports abdominal contents;
1)assists in flexing & rotation of trunk
2)assist in forced expiration
3)micturition
4)defecation
5)parturition (child labor)
6)vomiting

Question 3

Transversus Abdominis

Answer 3

Origin:
Lumbar Fascia
Iliac crest
Lateral ⅔ of the Inguinal ligament (connects the ilium to the pubis)

Insertion:
Xiphoid Process
Linea Alba
Symphysis Pubis

Nerve Supply:
Lower 6 Thoracic Nerves (T7-T12)
Iliohypogastric (T12-L1)& Ilioinguinal (L1)

Action:
Compress Abdominal Contents (to keep the abdominal cavity in place)

Question 4

Rectus Abdominis

Answer 4

Origin:
Symphysis Pubis
Pubic Crest

Insertion:
Costal Cartilages of 5,6,7 Ribs
Xiphoid Process

Nerve Supply:
Lower 6 Thoracic Nerves (T7-T12)

Action:
Compress Abdominal Contents (to keep the abdominal cavity in place)
Flexes the vertebral column
Accessory muscle for expiration

Question 5

Pyramidalis

Answer 5

Origin:
Anterior Surface of Pubis

Insertion:
Linea Alba

Nerve Supply:
12th Thoracic Nerve

Action:
Tenses the Linea Alba

Question 6

Psoas Major

Answer 6

Origin:
Transverse process
Bodies and IV Discs of 12th Thoracic & 5 Lumbar Vertebrae

Insertion:
Lesser Trochanter of Femur

Nerve Supply:
Lumbar Plexus (T12-L5)

Action:
1) Flex Thigh on Trunk
If thigh is fixed
Flexes trunk 
Sitting up from a lying position

Question 7

Psoas Minor

Answer 7

Origin:
Transverse process
Bodies and IV Discs of 12th Thoracic & 1st Lumbar Vertebrae

Insertion:
Pectineal Line

Nerve Supply:
Ilioinguinal (L1)

Action:
Action:
1) Flex Thigh on Trunk
If thigh is fixed
Flexes trunk 
Sitting up from a lying position

Question 8

Quadratus Lumborum

Answer 8

Origin:

1) Iliolumbar ligament
2) iliac crest
3) tips of the transverse process of the lower lumbar vertebrae

Insertion:
12th Rib

Nerve Supply:
Lumbar plexus (T12-L5)

Action:
Fixes 12th rib during inspiration; depresses 12th rib during forced expiration; laterally flexes vertebral column same side

Question 9

Iliacus

Answer 9

Origin:
Iliac Fossa

Insertion:
Lesser Trochanter

Nerve Supply:
Femoral Nerve(L2, L3, L4)

Action:
Flex thigh on trunk; If thigh is fixed, flexes trunk, sitting up from a lying position