Lower GIT Flashcards
Where does the descending thoracic aorta become abdominal aorta?
Aortic hiatus at the level of T12
Where does the abdominal aorta terminate?
Level of L4 where it bifurcates into right and left common iliac arteries
What do the common iliac arteries divide into?
External and internal iliac arteries
At what vertebral level does the celiac trunk arise?
Upper boarder of L1
What attaches jejunum and ileum to posterior abdominal wall?
Mesentery containing blood vessels and nerves
What are Payer’s patches?
Microscopic group of lymph nodes
Where are Payer’s patches found?
Ileum of small intestine
At what vertebral level does the superior mesenteric artery arise?
Lower boarder of L1
At what vertebral level does the inferior mesenteric artery arise?
Lower boarder of L3
At what vertebral level does median sacral artery arise?
L4
What is the median sacral artery?
Single parietal artery
Where does the ascending colon become the transverse colon?
Right colic flexure
Where does the transverse colon become the descending colon?
Left colic flexure
In terms of peritoneum, how is the ascending and descending colon described?
Retroperitoneal
In terms of peritoneum, how is the transverse colon described?
Intraperitoneal
What are 3 of the main branches of the inferior mesenteric artery?
- Left colic artery
- Sigmoid arteries
- Superior rectal artery
What body system is the spleen a part of?
Immune system
At what vertebral level does the inferior vena cava enter the thorax?
T8
What 2 branches of IVC correspond to parietal branches of abdominal aorta?
- Inferior phrenic veins
2. Lumbar veins
What 3 branches of IVC correspond to visceral branches of abdominal aorta?
- Right suprarenal vein
- Right and left renal veins
- Right gonadal vein
How do left suprarenal and left gonadal veins drain?
Indirectly via left renal vein
How does venous drainage occur from spleen, pancreas, gallbladder and GIT (except inferior part of rectum)?
Through portal system which delivers venous blood to liver and then IVC via hepatic veins
How is inferior part of the rectum drained of venous blood?
Via inferior rectal vein which ends in interior iliac vein
What are 4 main muscles of the posterior abdominal wall?
- Psoas major
- Psoas minor
- Iliacus
- Quadratus lumborum
Where does psoas major originate?
Bodies of vertebrae T12 - L5
Where does psoas major insert?
Lesser trochanter of the femur
What is the action of psoas major when trunk is stabilised?
Flexes thigh at hip join
What is the action of psoas major when the body is supine?
Flexes the trunk
What is the nerve supply of psoas major?
Anterior rami of L1 - L3
Where does psoas minor originate?
Vertebrae T12 - L1 and intervening intervertebral disc
Where does psoas minor insert?
Pectineal line of pelvic brim
What is the action of psoas minor?
Weak flexor of the trunk
What is the nerve supply of psoas minor?
Anterior rami of L1
What is the origin of iliacus?
Iliac fossa
What is the insertion of iliacus?
Lesser trochanter of femur
What is the action of iliacus?
Forms iliopsoas with psoas major as chief flexor of the thigh
What is the nerve supply of iliacus?
Femoral nerve (L2 - L4)
What is the origin of quadratus lumborum?
Transverse process of L5 and adjoining part of iliac crest
Where is the insertion of quadratus lumborum?
Inferior boarder of rib 12
What are 2 actions of quadratus lumborum?
- Fixes 12 rib
2. Lateral bending of trunk
What is the nerve supply of quadratus lumborum?
Anterior rami of T12 - L4
