GI - Class 3 Flashcards
What is the vertebral level of the oesophageal opening in the diaphragm
T10
List structures that traverse the esophageal opening in the diaphragm
oesophagus, vagus nerve, small esophageal arteries and lymphatics
What is the blood supply of the abdominal part of the oesophagus?
branches of left gastric artery
What is the venous drainage of the abdominal part of the oesophagus?
branches of the left gastric veins
What is the lymphatic drainage of the abdominal part of the oesophagus?
left gastric lymph nodes
What are the two orifices of the stomach?
pyloric orifice and cardial orifice
What are the two curvatures of the stomach?
lesser and greater curvature
What are the two surfaces of the stomach?
anterior and posterior
What is the pyloric sphincter?
thickening of the circular smooth muscle that controls chyme going into the duodenum
What are the gastric folds/ rug formed from?
gastric mucosa
In which portions of the stomach are they most apparent?
pyloric part and greater curvature
Which sphincter control the discharge of food from the stomach to the duodenum?
pyloric sphincter
What structures form the stomach bed (posterior wall of the omental bursa or lesser sac)
left dome of the diaphragm, left kidney, spleen, adrenal gland, splenic artery, colon and pancreas
What are the four groups of lymph nodes that drain the stomach?
gastric lymph nodes, gastro-omental lymph nodes, superior pyloric lymph nodes, inferior pyloric lymph nodes.
All the 4 stomach lymph nodes drain into which group pf lymph nodes?
celiac lymph nodes
What is the effect of increased vagal stimulation on the pylorus and gastric secretion?
Relaxes sphincter and increases gastric secretion.
How can vagotomy be used to treat over-active gastric secretion?
the arrangement of vagal branches to the stomach allows for highly selective vagotomy to be used to treat over- active gastric acid secretion. This denervates the fundus and body, decreasing secretion, while the supply to the antrum remains so preserving essential gastric motility.
What are the three parts of the small intestine?
duodenum, jejunum, ileum
Which part of the small intestine receives the opening of the bile and pancreatic duct?
duodenum
Where is the foregut/ midgut boundary in the small intestine?
second part of the duodenum
How are the different parts of the small intestine peritonised?
Duodenum - 1st part is intraperitoneal and rest is retroperitoneal
jejunum - intraperitoneal
ileum - intraperitoneal
Which part of the small intestine is the shortest, widest and most fixed part?
duodenum
What are the distinguishing characteristics of jejunum
- red colour, thick and heavy wall, greater vascularity
- longer vasa recta (straight arteries)
- few large loops of arcades (arterial loops)
- less fat in mesentery
- large, tall and closely packed circular folds
What are the distinguishing characteristics of ileum
- paler pink colour, thin and lighter walls, less vascularity
- shorter vasa recta (straight arteries)
- many short loops arcades (arterial loops)
- more fat in mesentery
- low and sparse circular folds, absent in the distal part.
n which part (jejunum or ileum) do the arterial arcades have many loops?
ileum
Which part of the autonomic nervous system (sympathetic or parasympathetic) stimulations reduces the secretion and motility of the intestine and also acts as vasoconstrictor?
sympathetic
The large intestine can be distinguished from the small intestine by the following features:
- teniae coli
- haustra
- omental appendices
What are teniae coli?
3 thickened bands of longitudinal smooth muscle
What are haustra?
sacculation or pouches of the colon between the teniae coli
How is the caecum peritonised?
intraperitoneal
How is the ascending colon peritonised?
retroperitoneal
How is the transverse colon peritonised?
intraperitoneal
How is the descending colon peritonised?
retroperitoneal
How is the sigmoid colon peritonised?
intraperitoneal
In which abdominal region is the caecum and appendix located?
right inguinal/ iliac
Which two structures open into the cavity of caecum?
distal ileum and appendix
What is McBurney’s point and why is it useful clinically?
a point on the abdominal wall that lies between the navel and the right anterior superior iliac spine and that is the point where most pain is elicited by pressure in acute appendicitis.
What is the arterial supply, venous drainage and peritonisation of the superior 1/3 of the rectum and anal canal?
- superior rectal artery
- superior rectal vein into portal vein
- retroperitoneal
What is the arterial supply, venous drainage and peritonisation of the middle 1/3 of the rectum and anal canal?
- middle rectal artery
- middle rectal vein into systemic drainage
- retroperitoneal
What is the arterial supply, venous drainage and peritonisation of the inferior 1/3 of the rectum and anal canal?
- inferior rectal artery
- inferior rectal vein into systemic drainage
- subperitoneal
What is the role of the pelvic floor in maintaining faecal continence?
contracts lumen
What other structures are involved in faecal continence?
external anal sphincter and internal anal sphincter
What is the significance of understanding the differences between visceral and somatic innervation of the anal canal?
- Visceral innervation via the inferior hypogastric plexus.
Sensitive to stretch. - Somatic innervation via the inferior anal nerves (branches of the pudendal nerve)
Sensitive to pain, temperature, touch and pressure.
The hepatoduodenal and hepatogastric ligaments are parts of which omentum?
lesser omentum
What is the falciform ligament and what structures lie within its free border?
Attaches the liver to the front body wall and separated the right and left lobes. Paraumbilical veins and the round ligament of liver
What structure in the free edge of the falciform ligament is a remnant of an embryonic blood vessel? What is the name of this vessel in the embryo?
Round ligament
fetal umbilical vein
How many layers of peritoneum are present in the greater omentum?
4 layers
Why is the greater omentum referred to as the abdominal policeman
In inflammation, inflammatory exudate causes the omentum to adhere to the site fo infection, and wrap itself around the infected organ. This localises the infection to a small area of the cavity, protecting against serious diffuse peritonitis.
What are the paracolic gutters?
spaces between the colon and abdominal wall.
Where are paracolic gutters found in relation to the large intestine?What is the clinical significance?
lie lateral to the colon. Allows a passage of infectious fluids.
List 3 abdominal viscera which lie in the free edge of a double layer of peritoneum described as the mesentery.
appendix, transverse mesocolon, sigmoid mesocolon.
What muscle type(s) form the muscularis externa in the oesophagus?
- inner circular layer
- outer longitudinal layer
What is the surface epithelium of the oesophagus?
stratified squamous
What secretory cells are present in the gastric pits of the stomach
- mucous cells
- parietal
- chief
- endocrine
What are folds of the mucous membrane in the small intestine?
plicae circularis
What are the finger-like projections called in the small intestine?
villi
What kind of epithelium is present in the small intestine?
simple columnar
Where, along the gut tube, do glands extend down beyond the muscularis mucosae (interna) into the submucosa?
duodenum
What part of the small intestine has Peyer’s patches
ileum
What are Peyer’s patches?
Lymphacitic aggregations
What is the transpyloric plane?
Imaginary axial plane located midway between the jugular notch and superior border of pubic symphysis, at approximately the level of L1 vertebral body.
List the structures present in the transpyloric plane
pylorus of the stomach, hilla of the kidney, neck of the pancreas, origin of SMA, begining of duodenum.
