Flashcards

The Small Intestine

anamijaaz English 75 cards

Cards in this deck (75)

1What is the midgut?The proportion of the embryo from which the following 7 structures develop:
- lower duodenum
- jejunum
- ileum
- caecum
- appendix
- ascending colon
- proximal 2/3 of transverse colon
2From which main artery do the structures of the midgut receive their blood supply?Superior mesenteric artery
3During development, the midgut herniates through a particular abdominal structure. Which structure is this? And what happens 4 weeks later?It herniates through the primitive umbilical ring. 4 weeks later, it returns to the abdominal cavity and rotates around the superior mesenteric artery.
4Around which artery does the midgut rotate during development?Superior mesenteric artery.
5How many degrees does the midgut rotate around the superior mesenteric artery?270
6What is the hindgut?The proportion of the embryo from which the following structures develop:
- last 1/3 (distal end) of transverse colon
- descending colon
- sigmoid colon
- rectum
- upper anal canal
7From which artery do the structures of the hindgut receive their blood supply?Inferior mesenteric artery.
8What is the cloaca?Terminal end of the hindgut
9The lower anal canal has the same embryological origin and neurovasculature to the hindgut. True or false?False; the lower anal canal develops from the invagination of surface ectoderm due to the proliferation of mesoderm surrounding anal canal (proctodeum).
10Where is the cloaca on this picture?
11Are structures attached to mesentries mobile or immobile?Mobile
12From where does the mesentry of the small intestine arise from?The root of the mesentery which extends from the duodenojejunal flexure to the ileocecal junction.
13Roughly how long is the small intestine?6 metres
14Name the three divisions of the small intestine and the approximate percentage/proportion they make up of the organ.Duodenum - 5%
Jejunum - <40%
Ileum - <60%
15Where does the small intestine start and end?Starts at the pyloric sphincter
Ends at the ileo-caecal junction.
16What is the caecum?an intraperitoneal pouch, that is considered to be the beginning of the large intestine
17Where does the duodenum start and end?Starts at the pylorus, and curves around the pancreas to end in the region of the upper part of the abdominal cavity where it joins the jejunum.
18The whole of the duodenum is retroperitoneal. True or false?False; the whole duodenum but the first part is retroperitoneal
19The duodenum is a major site for the absorption of vitamin B12. True or false?FALSE; the end of the ileum is responsible for the absorption of B12
20DWhich part of the small intestine is involved in the absorption of iron?Duodenum
21Which parts of the small intestine is involved in the absorption of folic acid?The jejunum
22Which two main things are absorbed in the late ileum?Vitamin B12 and bile salts.
23Why is the duodenum relatively immobile?Because it is largely retroperitoneal so most of it is not attached to a mesentery.
24Near which vetebral levels does the duodenum lie?L1-L3
25In which abdominal region does the duodenum mostly lie?Umbilical region
26What are plicae circulares?Circular folds in the mucous membrane which line the duodenum and increase its surface area.
27What is the ligament of Treitz?Thin muscle connecting the junction between the duodenum, jejunum, and duodenojejunal flexure to connective tissue surrounding the superior mesenteric artery and coeliac artery
28Does the duodenum begin to the left or to the right of vertebra L1?To the right of L1
29The final part of the duodenum ascends to and ends (to join jejunum) at which vertebra?L2
30What is segmentation?Contractions which move chyme in both directions, which allows greater mixing with the secretions of the intestines. Contractions of the CIRCULAR muscle. (Peristalsis; longitudinal muscle)
31Describe the course of the four parts of the duodenum, mentioning vertebrae in your answer.1st part begins to the RIGHT of L1.
2nd part descends down to L3.
3rd part courses to the LEFT of L2.
4th part ascends to L2 where it joins the jejunum.
32Describe the position of the duodenum in relation to the right kidney.The upper part of the 2ND part of the duodenum lies sandwiched between the hilum on the kidney and the ureter (which passes behind), with the kidney still lying posteriorly.
33What passes anteriorly to the upper half of the second part of the duodenum?Transverse colon
34The third part of the duodenum passes anteriorly to which main structures?Aorta, inferior vena cava
35Which vessels cross anteriorly to the third part of the duodenum?Superior mesenteric vessels
36What marks the junction of the foregut and midgut?The point of entry of the pancreatic and common bile ducts into the second part of the duodenum.
37Other than the foregut-midgut junction, what else does the point of entry of the bile duct and common hepatic duct into the second part of the duodenum demarcate?The boundaries of the superior and inferior pancreatico-duodenal arteries.
38What is the minor duodenal papilla?The opening of the accessory pancreatic duct into the descending second section of the duodenum
39Where do the superior and inferior pancreatico-duodenal arteries anastomose?At the hepatopancreatic Ampulla
40What is the sphincter of Oddi?Muscular valve that controls the flow of digestive juices (bile and pancreatic juice) through the ampulla of Vater into the second part of the duodenum
41Which hormone controls the Sphincter of Oddi?Cholecystokinin; CCK
42Where is CCK hormone produced and what produces it?In the duodenum by VIP, vasoactive intestinal peptide.
43Which parts of the small intestine are mainly covered by the greater omentum?Jejunum and ileum
44Are there more plicae circularis in the jejunum or in the ileum?In the jejunum
45Which of the ileum and jejunum has the thicker wall?Jejunum
46Which of the ileum and jejunum has a thinner mesentery, and why?Jejunum due to less fat.
47Why is the mesentery of the jejunum pinker than that of the ileum?It has a richer blood supply.
48What is the difference between the jejunal and ileal vasa recta?The vasa recta of the jejunum are long and few, compared to the ileum where they are numerous and short
49Which of the ileum and jejunum has simple arterial arcades?Jejunum; see picture.
50The jejunum lies mostly in which abdominal division?Umbilical region
51The ileum lies mostly in which abdominal division?Hypogastric and right inguinal region.
52Describe the plicae circularis in the ileum.Small in its superior part and absent in its terminal part.
53What are Peyer's patches, are where are they in the body?Aggregated lymph follicles in the mucous membrane of the ileum.
54Why would blockage of the vasa recta of both the ileum and the jejunum result in necrosis of the segment it supplies?Vasa recta of the gut are anatomical end-arteries
55Along which flexure do the ileum and jejunum attach to the posterior abdominal wall via a mesentery?Duodenojejunal flexure
56How long, in cm, is the mesenteric attachment of the ileum and jejunum at the duodenojejunal flexure?15 cm
57Which of the ileum and jejunum has a characteristic solid radiological appearance like so?Ileum
58The duodenum receives its blood from which specific arteries?Superior and inferior pancreaticoduodenal arteries.
59The superior pancreaticoduodenal artery branches off from which other artery?Gastroduodenal artery
60The inferior pancreatico-duodneal artery branches off from which artery?Superior mesenteric artery
61From which artery do the ileum and jejunum receive their blood supply?Branches off the superior mesenteric artery which are named jejunal/ileac arteries as appropriate.
62How does the lymphatic drainage of the abdomen relate to the arterial drainage?It follows the same pattern of the arterial supply
63What are pre-aortic nodes and where are they?Lymph nodes around the superior/inferior mesenteric arteries and coeliac trunk. Lymph vessels converge at these nodes and drain into them.
64What is the cisterna chyli?Lymphatic sac situated below and to the right of the aortic opening of the diaphragm. The lymph drains into here after the pre-aortic nodes.
65The efferent lymph vessels from the cisterna chyli travel where?Through the aortic hiatus in the diaphragm to become the thoracic duct.
66Describe the course of the thoracic duct until it drains into the junction of the internal jugular and left subclavian vein.Lies posteriorly to the oesophagus in the inferior/posterior mediastinum, then moves to the left hand side at the plane of the sternal angle, where it arches over in the root of the neck to join the subclavian/jugular vein.
67What is metastasis?Spread of cancer or disease from one organ to another.
68Via which nodes does metastasis from the colon occur?Superior or inferior mesenteric nodes as well as the scattered nodes en route, depending on the location of tumour.
69There are lymphatic anastomoses between the superior mesenteric and coeliac nodes, true or false?True
70Where is foregut pain in terms of abdominal divisions?Epigastric
71Where is midgut pain in terms of abdominal divisions?Umbilical
72Where is hindgut pain in terms of abdominal divisions?Hypogastrium
73Visceral pain is carried by sympathetic nerves between which vertebrae?T6-L2
74Pain sensation to the pelvic organs arises from S2, S3 and S4. Is this pain from the sympathetic or parasympathetic nervous system?Parasympathetic
75Somatic afferents supplying the abdominal wall enter the spinal cord between which levels?T5 and L2