Anterior abdominal wall/Peritoneal arrangement

Question 0

External Oblique

Answer 0

Flat muscle
Origin: external 5th-12th ribs
Insertion: linea alba, pubis, anterior iliac crest
Innervation: T7-T12
Action: move trunk, support viscera, respiration (forced)

Question 1

What are the 7 layers of the anterior abdominal wall?

Answer 1

1. Skin
2. Superficial fascia
   - -camper’s fascia-fatty layer
   - -scarpa’s fascia-membranous layer
3. deep fascia-potential space between deep fascia and membranous fascia
4. muscles (3 flat, 2 strap)
5. transversalis fascia
6. endoabdominal fat
7. parietal peritoneum

Question 2

Internal Oblique

Answer 2

Flat muscle
Origin: anterior iliac spine, inguinal ligament, thoracolumbar fascia
Insertion: 10th-12th rib, linea alba, pubis
Innervation: T7-L1
Action: moves trunk, supports viscera, respiration (forced)

Question 3

Transversus Abdominis

Answer 3

Flat muscle
Origin: iliac spine, inguinal ligament, thoracolumbar fascia, 7-12th costal cartilage
Insertion: linea alba, pubis
Innervation: T7-L1
Action: support, compress viscera, respiration (forced)

Question 4

Rectus Abdominis

Answer 4

Strap muscle
Origin: pubis
Insertion: xiphoid process and 5th-7th costal cartilages
Innervation T7-T12
Action: moves trunk

Question 5

Pyrimidalis

Answer 5

Strap muscle
*may not be present in everyone
Origin: pubis
Insertion: linea alba
Innervation ? (possibly same as rectus abdominis)
Action: tenses linea alba

Question 6

What is the ligament of Treitz?

Answer 6

suspensory muscle of duodenum, supports duodenojejunal junction

Question 7

What are some differences between the jejunum and ileum?

Answer 7

Jejunum has more plicae, less encroaching fat, and longer vasa recta (J is longer than I), ileum has more lymph aggregates (Peyer’s patches)

Question 8

What are the tenia coli and what do each attach to?

Answer 8

3 longitudinal muscle bands

1. free (attaches to nothing, on anterior)
2. omental (attaches to greater omentum)
3. mesocolic (attaches to mesocolon)

Question 9

What makes up the teres ligament?

Answer 9

Round ligament and falciform ligament

• falciform is large ligament separating right and left lobes of liver
• round ligament is small projection off of falciform ligament

Question 10

What sits in the left and right sagittal fossa?

Answer 10

left-ligamentum venosum and round ligament (umbilical vein)

right-gall bladder and IVC

Question 11

What is mesentery?

Answer 11

peritoneum between organs and posterior abdominal wall

Question 12

What is omentum?

Answer 12

peritoneum between two organs

Question 13

What does the lesser omentum run between?

Answer 13

Liver and stomach, duodenum

Question 14

What does the greater omentum run between?

Answer 14

stomach and spleen, transverse colon, diaphragm