The Intestines and The Anus Flashcards
The highest point of the abdomen is the highest point of the diaphragm which is at what vertebral level
T8
What is the most inferior part of the abdomen
Pelvic inlet
Pylorus, duodenum , jejunum , ileum , caecum , ascending Color , traverse colon , descending colon , sigmoid colon , rectum …
Anal canal
What are the two turning points of the large Intestine
Hepatic flexure and then splenic flexure
3 branches of the abdominal aorta supply the intestines
This is the celiac trunk
Sup. Mesenteric artery
Inf. mesenteric artery
What Levels do these break off the abdominal aorta and what do they supply
T12 forgut
L1 midgut
L3 hindgut
The superior mesenteric artery supplies the ascending colon and majority of transverse and small intestine so distal transverse colon is where the midgut ends
Which artery from the superior mesenteric artery anastomoses with branches of the inferior mesenteric artery so their is collateral circulation so if clot In IMA still works
Middle colic artery
Venous drainage runs back up to liver- liver uses that blood and then goes back into circulation - what vein takes this
Hepatic portal vein
Superior mesenteric vein drains midgut and join with splenic artery to form hepatic portal vein
The inferior mesenteric vein joins splenic vein at different point to then become hepatic portal vein
Forms what kind of letter
H
The small intestine is within the midline of the abdomen and is framed by the large intestine it has e part duodenum starting at pylorus at L1 and runs into real shape from left to right jejunum then ileum which occupies lower right quadrant with the caecum.
General direction of left upper to right lower
At what level is the dudoenojejunal junction
L3
The small interior ends in RIF ileocecal valve
L4 - bowel is just associated with itsel
L3 inferior poles of kidneys
In larger individuals with large central abdominal fat they can have a higher traverse colon. In thin individuals there is no far so how low could the transverse colon be
L5
Is the bowel intraperitoneal ?
Yes surrounded by blood vessels behind and mesenteric
What layers is the myenteric plexus between
Muscularity externa - circular and longitudinal
What are valvulae connivents
Circular folds increase SA
Small intestine get villi
Duodenum is made up of 4 parts, superior , descending , horizontal and ascending which part Is intraperitoneal
Superior
Ampulla of vater
Bile duct enter the duodenum - bile is digestive juice and that has to enter the duodenum to help with digestion and this is said to correspond with embryo logical foregut
SMA will emerge just superior to where the left renal vein travels across the anterior face of the abdominal aorta - the runs to anterior part of duodenum
Left renal vein is visible just under what
Pancreatic tail
Aorta enters abdomen through diaphragm T12 than the IVC T8
Coeliac trunk supplies the foregut and has branches such as common hepatic artery and gastroduodenal artery which runs behind the superior part of the duodenum is this area prone to ulcers
Yes
Two differences between the jejunum and ileum
Jejunum has much thicker muscular wall. More circular in its lumen compared to the ileum
Ileal loops tend to lie in the inferior part of the abdomen and pelvis
Jejunum has less villi
Jejunum has 1-3 so fewer arterial arcades ( circles) and fewer and longer vasa recta
True ileum has 2-6 arcades and has numerous shorter and thinner vasa recta
What are peyers patches ?
Aggregates of lymphoid tissue found in the luminal wall and are often palpable - bowel intussusception in children - bowel folds in ahead of it
Ileum has loads found through the length
What is a plexus
Web of nerves - come from the spinal cord branch off and then come back together again - some are autonomic and some are soamticsly innervated
Ganglion
2 neurones synapse together
Greater splanchic nerve
t5-9
Lesser splanchic nerve
T10-11
Least splanchic nerve
T12
Sympathetic runs through splanchic nerves and parasympathetic through vagus nerves
Where is most water is absorbed from undigested chyme
Large intestine
4 distinct features that separate large intestine from small intestine
Larger diameter
Teniae coli - emerge from appendix and form 3 strands - merge again at rectum
Haustra
Omental appendices
3 tenia coli
Mesocolic , omental and free tenia
Diverge. And then reconnect
Haustra
Tenia coli smooth muscle and just have a tone of contracted they pull bits of the large vowel together to form pouches called haustra producing wrinkles Like bubbies and bulges
What tool can you use to tell the difference between haustra and valvulae conniventes
Haustra don’t cross the whole width
Valvulae conniventes cross the whole width
X-ray
Omental appendage
Little fat tags on the large intestine
What parts of the large intestine are retoperiotneal
Ascending and descending
Paracolic gutters
Potential space between the lateral surface of ascending surfaces of colon and peritoneal ,membrane at the side of them- path of least resistance so infection runs
Rectum is 15cm - anal canal 4-5cm
Anal viaves secrete mucus and get faeces out of anal canal where are they found
Anal columns
What is the denate line
Embrylogical divide between endoderm and ectoderm
Transfer of columnar epithelium to stratified squamous epithelium of skin
What muscle supports rectum
Lavatory ani
Ischiorectal fossa
Canal
Abscess
Ischial tuberous it and medially
Pudendal canal sup to inf
artery vein then nerve abscesses injur nerve
Gangrene
Appendices pain
Travelling pain starts in midline as the visceral peritoneum is irritated . This layer only has a sensory supply from visceral to autonomic fibres so pain generalised to a dermatome. As inflammation worsens the parietal peritoneum irritated so pain localised to RIF where the appendices usually sits.
Umbilicus to right iliac fossa
Diverticulitis is classically described as LIF maybe opposite in Asian, infection if one of the outpouchings - localised well
True or false
True
Mcburnleys point is found where
What is this the common location for
Between the umbilical and antihero superior iliac spine - 1\3 from the ASIS
Appendix’s
In small vs large vowel obstruction
Small bowel is pain central and valvulae conniventes cross all lumen and dilated bowel about 3cm
What happens in large bowel obstruction
Pain in normally in lower abdomen
Haustra do not cross the lumen
Dilated bowel to over 6cm
Where does the small intestine finish
Enterocytes msot numerous cell - nutrient electrolyte and fluid absorption
Ileocecal valve
Terminal ileum absorbs bile salts and B12 special
All small bowls in intraperitoneal except distal 3 parts of the dudodneum
Level of transverse colon
L3 - umbilical level
Left colic flexure more superior than right as liver not pushing down
Sigmoid colon is continuous with the rectum
Sigmoid colon is continuous with the rectum at what vertebral level
S3
In the intestines what parts are retoperitoneal
Ascending , descending colon and distal 3 parts of the duodenum
Rectum and anus are sub peritoneal
The parasympathetic fibres in the juejunum and ileum derive from what
Posterior cabal trunk
Where the internal sphincter ( autonomic ) and external sphincter ( somatic ) meet is called
Anorectal ring
