the intestines Flashcards
What are the three parts of the small intestine?
Duodenum
Jejunum
Ileum
Where does the small intestine extend from and to?
It extends from the pylorus of the stomach to the ileocaecal junction (where the ileum joins the caecum).
What are the 8 main parts of the large intestine?
Caecum
Appendix
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
Rectum
Anal canal
What is the shape and position of the duodenum?
The duodenum forms a C-shaped loop in the right upper quadrant, extending between L1 and L3 levels. (Use the first diagram from the slide here.)
How are the jejunum and ileum arranged?
The jejunum and ileum coil into a loop and span across all quadrants of the abdomen
How does the large intestine relate to the small intestine?
The large intestine forms a frame around the small intestine, enclosing it within its loop.
What is the duodenum, and what is its function?
The first part of the small intestine, responsible for nutrient absorption. It has a C-shaped loop that curves around the head of the pancreas.
Where does the duodenum begin and end?
Starts at the pylorus of the stomach.
Ends at the duodenojejunal flexure (L2 level, left of midline).
Is the duodenum retroperitoneal?
Yes, except for the first part, which is covered by the hepatoduodenal ligament.
What are the four parts of the duodenum, and their vertebral levels?
How is the mucosa of the duodenum similar to the stomach?
It has circular folds, which increase surface area for digestion and absorption.
What is the major duodenal papilla, and what is its function?
The site where bile and pancreatic juice enter the duodenum, aiding in digestion.
What anatomical landmark marks the transition from the foregut to the midgut?
The major duodenal papilla is the boundary between the foregut and midgut.
What are the two duodenal papillae, and what do they do?
Major duodenal papilla – Receives bile and pancreatic enzymes via the common bile duct and major pancreatic duct.
Minor duodenal papilla – Receives secretions from the accessory pancreatic duct.
Which arteries supply the duodenum?
Superior pancreaticoduodenal artery (SPDA) – from gastroduodenal artery (coeliac trunk).
Inferior pancreaticoduodenal artery (IPDA) – from superior mesenteric artery (SMA).
How is the duodenum’s blood supply divided between the foregut and midgut?
Proximal to major duodenal papilla → SPDA (Coeliac trunk, foregut).
Distal to major duodenal papilla → IPDA (SMA, midgut).
Where does venous drainage of the duodenum occur?
Drains into hepatic portal vein, superior mesenteric vein, or splenic vein.
How much of the small intestine is made up by the jejunum and ileum?
Jejunum: 2/5 of the small intestine length.
Ileum: 3/5 of the small intestine length.
How do the vasa recta (straight arteries) differ in the jejunum and ileum?
Jejunum: Long vasa recta.
Ileum: Short vasa recta.
How do the arterial arcades differ between the jejunum and ileum?
Jejunum: Few large loops.
Ileum: Many short loops.
Where is there more fat in the mesentery – jejunum or ileum?
Jejunum: Less fat.
Ileum: More fat.
How do circular folds differ between the jejunum and ileum?
Jejunum: Prominent and tightly packed.
Ileum: Sparse, almost absent in the distal part.
Which part of the small intestine has more lymphoid tissue?
Jejunum: Few lymphoid tissues.
Ileum: Many lymphoid follicles.
What is the mesentery, and what does it do?
A fan-shaped fold of peritoneum that attaches the jejunum and ileum to the posterior abdominal wall.
