Lecture 6 Flashcards
What is the outline of the abdominal cavity?
Abdominal contents not constrained to abdominal cavity
Oesophagus goes through thorax
1/2 way into rib cage
extends down into pelvic cavity- stopping at inguinal ligament and pelvic inlet
Abdominal Aorta
T12-L4 T12= Coeliac trunk (short and stubby) -under diaphragm -Foregut a) Left gastric b) splenic c) Common hepatic L1= Superior Mesenteric (SMA) -MidGut L3= Inferior Mesenteric (IMA -Hind Gut L4= Right and Left common Iliac Arteries
Foregut Component Viscera
Distal Oesophagus
Stomach
Liver and Gall Bladder
Proximal 1/2 of Duodenum
Pancreas- blood supply from 2x sources (Superior Mesenteric Artery)
-Oral Cavity is the start of the Digestive system
-Spleen not foregut
-Referred pain of the stomach is to the Epigastric region
What is the blood supply of the Pancreas?
Blood Supply from 2x sources
- Coeliac axis
- Superior Mesenteric Artery
Foreguts Neurovascular and Lymphatic Supplies
Arterial: branches of Coeliac axis from T12 Abdominal Aorta
Venous: Portal Vein (direct drainage)
Nerve: Coeliac Plexus (T12)
Lymphatics: Pre-aortic nodes T12 (Coeliac nodes)
Stomach Surface Anatomy
Shape and Position changes as stomach fills
Generally Epigastric Region (Left of midline)
Liver= ~Rib 5
Fundus= ~Rib 5-6
Oesophagus= ~Costal Cartilage 7-8
Distal end/Pylorus= Trans-pyloric Plane= ~L1 Vertebral level
3x muscular layers:LOMCOI
1. Longitudinal outer
2. Circular middle
3. Oblique inner - contains Rugae to increase SA surface area and expandability
-Cardia region- before fundus
- 2x Curvatures:
Lesser C: Lesser Omentum attaches
Greater C: Left, inferior,
Stomach Arterial supply
supply from Coeliac Trunk Lesser Curvature: 1. Left Gastric (Direct branch off Coeliac Trunk)-lesser curvature + distal oesophagus 2. Right Gastric (Common Hepatic) -Anastomose Greater Curvature: 1. Left Gastro-omental/epiploic (Splenic)-largest artery 2. Right Gastro-omental (Gastroduodenal)-(Common Hepatic) -Anastomose -Also supply greater omentum Fundus: 1. Short Gastric (Splenic)
Duodenum Structure
Foregut/Midgut
Origin- immediately following stomach’s Pyloric region ( Superior 1st part Trans-Pyloric Plane = Intraperitoneal)
Descending 2nd: wraps around head of pancreas (RH of midline)
-Biliary tree goes through head of pancreas and enter 2nd Duodenum)
Inferior 3rd: back over midline. ontop of IVC and Aorta. underneath Superior Mesenteric Vessels.
Ascending 4th: Ascends to Duodenojejunal Flexure (L of midline)
2nd-4th= Retroperitoneal (against body wall)
1/2 duodenum = Transition to midgut (Blood, nerves, lymphatics change)
Duodenum Neurovascular and Lymphatic Supplies
- Superior 1/2:
a) Arterial: Superior Pancreatoduodenal branches (from gastroduodenal artery of coeliac origin)
b) ANS Nerves: Ceoliac Plexus T12
c) Venous: Portal Vein Directly
d) Lymphatic drainage: Pre-aortic Coeliac nodes T12 - Inferior 1/2:
a) Arterial: Inferior pancratoduodenal branches (from Superior Mesenteric origin) - ANS Nerves: Superior Mesenteric Plexus L1
- Venous: Superior Mesenteric Vein (SMV) (then forms portal vein)
- Pre-arotic Superior Mesenteric Nodes L1
Where is the location of Para-aortic nodes?
On the sides of the Kidney
What is the relationship between Biliary tree and Duodenum?
enters 2nd part of duodenum
1. Ampulla of Vater:
“ampulla” = Swelling in a tube
Union of Common Bile duct + Main Pancreatic Duct
- Major Duodenal Papilla:
“papilla”= nipple like process- where bile is released
Enters through wall of 2nd part of Descending Duodenum
Controls flow of: - Bile from Liver (emulsify fat for digestion)
- Pancreatic Juice from pancreas
into the Duodenum via Sphincter of Oddi
Sphincter of Oddi= circular muscular component - (Minor Duodenal Papilla sometimes present)- with accessory pancreatic duct (9% of duct)
Component Viscera of Midgut
Distal half of Duodenum Jejunum Ileum Caecum & Appendix Ascending Colon 2/3 Transverse Colon
Midgut Neurovascular and Lymphatic Supplies
Arterial: Branches of Superior Mesenteric Artery -abdominal aorta L1
Venous: Superior Mesenteric Vein
Nerves: Superior Mesenteric Plexus L1
Lymphatics: Pre-Aortic nodes L1 (superior Mesenteric Nodes)
-Pain referred to Umbilical region
Structural features of small intestine
Mid Gut
Long thin convuluted muscular tube - Increase SA
~6m long
Bulk of digestion
1. Jejunum 2/5th of length
2. Ileum 3/5th of length
Suspended from body wall via Mesentery
-Fan shaped folds of peritoneum enclosing gut tube
-allows ingress/egress of vessels, nerves, lymphatics
Identifying difference: Arterial Arcade Patterning
Jejunum: 1 or 2 arcades + long branches
Ileum: many arcades + short branches
Other Differences: width, mesenteric fat, lymphoid tissue
Small Intestine Neurovascular and Lymphatic Supply
Arterial: Branches of Superior Mesenteric Artery L1
-Jejunal arteries
-Illeal arteries
ANS Nervous supply: Superior Mesenteric Plexus L1
Venous: Superior Mesenteric Vein
Lymphatic Drain: Pre-aortic Superior Mesenteric nodes L1