Gut and Blood Supply Flashcards
Coeliac Trunk divides into and supplies
left gastric
splenic
common hepatic
“foregut”
What are the spinal levels of the coeliac trunk, SMA and IMA?
Coeliac trunk= T12
SMA= L1
IMA= L3
Blood supply to the pancreas?
From both Coeliac trunk AND SMA
Component viscera of Foregut?
oesophagus stomach Liver proximal 1/2 duodenum *pancreas
Neurovascular supply and lymphatics to Foregut?
Arterial: branches off coeliac axis (abd. aorta @ T12)
Venous: Portal vein
Nerve Plexus: Coeliac plexus @ T12
Lymphatics: Pre-aortic nodes @ T12 (coeliac nodes)
Where is pain referred to in foregut?
Epigastric region
Location of Stomach
Epigastric region (to left of midline)
Fundus: ~ ribs 5-6
Pylorus: L1 vertebral level at the ‘transpyloric plane’
Oesophagus meets stomach @ ~ costal cartilage 7-8
- the stomach shape changes as it fills!
Layers of stomach and what lines its inner wall?
Outer longitudinal
middle circular
inner oblique
‘Rugae’ lines the inner wall to increase SA & expandability
Arterial Supply of lesser curvature?
- Left gastric (direct from coeliac trunk) > LC and distal oesophagus
- Right Gastric (from common hepatic
These anastamose
Arterial supply of Greater curvature?
- Left Gastro-omental (splenic)
- Right Gastro-omental (gastroduodenal (from CH))
Arterial supply to Fundus
Short Gastric (splenic) "it sits up by the spleen"
Condition where people eat there own hair?
Trichophagia
Structure of the foregut/midgut transition of the duodenum
Are these intra or retro peritoneal?
1st) Trans-pyloric plane is superior
2nd) Descends, wraps around head of pancreas (RHS of midline)
3rd) Inferior, crosses back over IVC & aorta (under SM vessels)
4th) Ascends to duodenojejunal flexure (LHS of midline)
1st = INTRA peritoneal
2nd, 3rd, 4th) RETROperitoneal
Neurovascular and lymphatics to Superior half of duodenum
Arterial: Superior pancreatoduodenal branches (gastroduodenal (coeliac))
ANS: Coeliac Plexus @ T12
Venous: direct to portal vein
Lymphatic: pre-aortic coealiac nodes @ T12
Neurovascular and lymphatics to inferior half of duodenum
Arterial: inferior pancreatoduodenal branches (SMA)
ANS: Superior Mesenteric Plexus @ L1
Venous: SMV to then form portal vei
Lymphatic: Pre-aortic SM nodes @ L1
Difference between an ampulla and a papilla
Ampulla = swelling in a tube Papilla = nipple like proccess (not to be confused with the sphincter that is a muscle)
Ampulla of Vater
Union of common bile duct(liver) & main pancreatic duct
Major duodenal papilla
Enters through descending duodenum (2nd part) and controls flow of bile (liver) and pancreatic juice (pancreas) into the duodenum vis the ‘sphincter of Oddi’
When is the minor duodenal papilla present
When the accessory duct is present (9%)
Component viscera of midgut
distal half of duodenum jejunum ileum caecum&appendix ascending colon 2/3 transverse colon
Neurovascular and lymphatics
Arterial: Branches of SMA (abd. aorta @L1)
Venous: SMV
Nervous: SM plexus @ L1
Lymphatics: pre-aortic nodes @ L1 (SM nodes)
Describe the Small intestine
long thin muscular tube 6m long 2/5 jejunum 3/5 ileum suspended via body wall by mesentery
Mesentery
- fan-shaped folds of peritoneum enclosing the gut tube
- allows ingress-egress of vessels, nerves and lymphatics
Whats the main identifying difference between jejunum and ileum?
arterial arcade patterning
Jejunum = 1-2 arcades with long branches (vasa recta)
Ileum = more arcades with very short branches
Arterial supply specifically to the small intestine?
branches of SMA (abd. aorta @L1)
jejunal arteries
ilieal arteries
The junction between SI and Colon is called?
Ileocaecal Junction
The flexures of the colon are? Which is higher?
Hepatic flexure (by liver) Splenic Flexure (by spleen)
Splenic flexure is higher as there is no liver pressing down on it
Function of the large intestine
Absorbtion of water & electrolytes
Stores undigestable materials until expelled
Haustra
Sacculations of the wall for storage
Tenae Coli
Longitudinal muscles collected into 3 bands (continuous with smooth muscle of small intestine)
Appendices Epiploicae and its clinical relevance
Fatty tags (none on Small intestine)
These can become inflammed and infected and mimic appendicitis
The LI is found in all regions except
umbilical
Midgut arterial supply
Midgut = from SMA @L1
caecum/appendix: caecal & appendicular arteries (ileocoelic art.)
Ascending colon: Right coelic art
Proximal 2/3 Trans colon: middle coelic & marginal art.
Hindgut arterial supply
Hindgut = from IMA @L3
Distal 1/3 trans colon: marginal & left coelic art
Descending colon: left colic
sigmoid colon: sigmoid art
Marginal artery
anastamotic point between SMA and IMA
Weird thing ileocolic does?
Loops back on itself and anastamoses
What part of the large intestine becomes muscularised and resembles SI
descending/sigmoid colon
Midgut NV and lymphatic supply?
Art: branches of SMA @ L1
Veins: SMV
ANS: Superior mesenteric plexus @ L1
Lymphatics: Pre-aortic superior mesenteric nodes @ L1
Hindgut NV and lymphatics supply?
Art: branches of IMA @ L3
Veins: IMV
ANS: Inferior mesenteric plexus @ L3
Lymphatics: Pre-aortic inferior mesenteric nodes @ L3
What is the Rectum, where is it formed
The final storage deposit, SC becomes rectum @ S3 vertebral level.
Pierces pelvic diaphragm at tip of coccyx to become anal canal
Is retroperitoneal
Sup 1/3= covered in peritoneum
middle 1/3 = ant peirtoneum
inf 1/3= infraperitoneal
Nervous supply and lymphatics of rectum
ANS:
prximal 1/3 = IM plexus @ L3
Distal 2/3 = inferior hypogastric plexus
Lymphatics:
Proximal 1/3: To preaortic nodes @ L3
Distal 2/3: To internal iliac nodes
Portal vein =
Splenic(IMV) + SMV
Parasympathetic Supply from
Vagus nerve (CN 10) also pelvic splanchnic nerves S2-4
Sympathetic Supply from
thoracic, lumbar and sacral splanchnic nerve
- from T5-L2 sympathetic ganglia (the full amount is T1-L2)
What do the PS and sympathetic control?
- viscera, glands, BVs
- smooth muscle
- non-concious control
- motor and sensory
Splanchnic Nerves
specifically visceral nerves, go direct to organs.
Form plexus on aorta eg) coeliac, SMA plexus
Foregut ANS > where is pain refered to
S: Greater splanchnic T5-9
PS: Vagus [X]
Epigastric region
Midgut ANS > where is pain refered to
S: Lesser splanchnic T10-11
PS: Vagus [X]
Umbilical Region
Hindgut ANS > where is pain refered to
S: lumbar (L1-2)/sacralsplanchnic(S2-4)
PS: Pelvic Splanchnic (S2-4)
*no pain referral to S2-4, only to T1-2
Suprapubic region
Steps of Appendicitis?
1) appendix becomes inflamed (stretch recep.)
2) afferent sympathetic fibres refer back to T10-11 dermatomes
3) There’s a broad diffuse pain around umbilical region
4) Appendix grows until it starts pressing on body way = somatic sensory pain
5) Now pain is acute, localised to LRQ
