The Stomach And Small And Large Intestine Flashcards
Where does the oesophagus pass through the diaphragm?
Passes through the the oesophageal hiatus in the diaphragm.
At level of T10.
Sphincter there prevents reflux of stomach contents up the oesophagus.
What is the distal oesophagus (2cm in abdomen) supply and drainage?
Supplied by branches from left gastric artery.
Venous drainage towards both systemic system and portal system.
SO the site of portosystemic anastomoses.
What is chyme?
The stuff the stomach breaks food down into
What are the 4 parts the stomach is described in?
Cardia
Fundus
Body
Pyloric
What is the fundus of the stomach?
The most superior part of the stomach. Superior to the entry level of the oesophagus and is usually filled with gas. (little bump on ‘left’)
What is the body of the stomach?
Largest part of the stomach.
Middle bit, main sac.
What is the cardia of the stomach?
First bit - part that connects oesophagus to the stomach. Contains a cardiac sphincter.
What is the pyloric part of the stomach?
Distal to the body.
Pyloric antrum - wide and tapers towards the pyloric canal.
Pyloric canal - narrow and contains the pyloric sphincter.
Right and left borders of the stomach?
Right - lesser curvature
Left - greater curvature
How is the stomach related to the lesser sac of the abdomen?
Posterior surface of the stomach forms the anterior wall of the lesser sac. Lesser sac and structures that form it are posterior to the stomach.
What does the lesser omentum connect?
Connects the lesser curvature of the stomach to the liver. Has a free edge, posterior to which is the lesser sac.
What does the free edge of the lesser omentum contain?
Hepatic artery
Hepatic portal vein
Bile duct
Is the stomach intraperitoneal or retroperitoneal?
Intraperitoneal (according to teachmeanatomy)
Which blood vessels supply the stomach and where do they branch from?
Lesser curvature: left (from common/proper hepatic) and right gastric arteries that anastomose
Greater curvature: left(from splenic) and right (from gastroduodenal from common hepatic) gastro-omental arteries that anastomose
Branch from the coeliac trunk that leaves the abdominal aorta anteriorly.
What compromises the foregut?
Stomach
First half of duodenum
Liver
Gallbladder
Pancreas
Describe venous supply of the stomach
R/L gastric veins and R/L gastro-omental veins accompany their respective arteries.
Ultimately drain into hepatic portal vein.
Describe innervation to the stomach
Vagus nerve - parasympathetic fibres for peristalsis and gastric secretion
Greater splanchnic nerve - preganglionic sympathetic fibres from T5-T9 that pass through the sympathetic trunk and synapse in prevertebral ganglia around coeliac trunk.
Post ganglionic fibres travel to the stomach.
Hiatus Hernia
Gastric Ulcer
Pyloric stenosis
Gastric cancer
What are the three parts of the small intestine?
Duodenum
Jejunum
Ileum
What is the position of the duodenum?
Is it intra or retro peritoneal?
What does it develop from?
Continuous with pylorus, curves in a C-shape around the head of the pancreas.
Most of it is retroperitoneal.
First half - embryo foregut (supplied by coeliac trunk)
Second half - embryo midgut (supplied by superior mesenteric)
What is the major duodenal papilla?
Opening of the bile duct and main pancreatic duct into the duodenum.
Approximately halfway along the internal wall of the duodenum.
What structure lies approximately halfway along the internal wall of the duodenum?
The major duodenal papilla
What are the similarities between the jejunum and the ileum? [4]
Both
- intraperitoneal
- ‘suspended’ from the inferior abdominal wall by mesentery of small intestine.
- derived from the embryological midgut.
- sites of nutrient absorption, so vast surface area by folded mucosa(plicae circulares) with villi and microvilli
Are the jejunum and ileum intraperitoneal or retroperitoneal?
Both are intraperitoneal. Suspended from posterior abdominal wall by mesentery of small intestine.
What are the difference between the jejunum and the ileum?
Internally, the plicae are more pronounced in the jejunum.
The internal ileum has Peyer’s patches - large submucosal lymph nodules
Externally, they appear the same.
What are plicae circulares?
Mucosal folds in the small intestine, more pronounced in jejunum than the ileum.
What are Peyer’s patches?
Large submucosal lymph nodules found in the ileum but not the jejunum.
What is Meckel’s diverticulum?
In some people
Blind-ended diverticulum 1m from the termination of the ileum. Remnant of connection between midgut loop and yolk sac in the embryo.
If inflamed, may mimic appendicitis.
What is the first part of the large intestine?
What junction does it meet the ileum at?
What area is this junction in?
- Caecum
- Meets at ileocaecal junction
- In the right iliac fossa
What are the parts of the large intestine?
Caecum
Appendix
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
Rectum
Anal canal
What is the function of the large intestine?
Reabsorbs water from faecal material to form semi-solid faeces
What is the taeniae coli?
Outer longitudinal muscle layer of large intestine is organised into 3 bands called taeniae coli.
What muscles layers are there in the large intestine?
Outer longitudinal muscular layer - taeniae coli
Inner circular muscle layer forms haustra or haustrations - bulges
What and where are epiploic appendages?
Fatty tags that mark the point that blood vessels penetrate intestinal wall
Of large intestine
What is the appendix attached to? What does it contain?
the caecum - at McBurney’s point - connected by the mesoappendix
it contains lymphoid tissue
Ascending colon
Continuous with caecum
Runs vertically, in right paracolic gutter
Retroperitoneal
Makes a 90’ turn in right upper quadrant
Bend is called hepatic flexure
What is the hepatic flexure?
Where the ascending colon does a 90’ turn into the transverse colon. Also called the right colic flexure.
Is the transverse colon retro or intra peritoneal?
How is it attached?
Intraperitoneal
Suspended from the posterior abdominal wall by the transverse mesocolon
What is the splenic flexure in the gut?
Transverse colon turns 90’ into the descending colon at splenic flexure (sometimes called left colic flexure).
Tethered to the diaphragm by the phrenicocolic ligament.
Where does the transverse colon originate from embryologically?
Midgut AND hindgut
Midgut proximal two thirds
Distal third from hindgut
Means the two parts are supplied by different blood vessels
Descending colon
Retroperitoneal (also secondarily retroperitoneal)
Runs vertically in left paracolic gutter
Sigmoid colon
Which quadrant?
What does it connect to?
What is the rectosigmoid junction?
What is the mesentery called?
Is it intra or retroperitoneal?
Lower left quadrant
Descending colon and rectum
Makes a 90’ turn inferiorly as it approaches the midline - called rectosigmoid junction
Mesentery - sigmoid mesocolon
Intraperitoneal
What is the rectosigmoid junction?
The ‘s -bend’ in the sigmoid colon
90’ turn inferiorly towards the pelvis
Rectum
Retro or intra peritoneal?
Connects to?
Function?
Retroperitoneal
Rectosigmoid junction (S3) and Anal canal
stores faeces
What level does the coeliac trunk leave the aorta at?
T12
