Anatomy of the GI Part 2 Flashcards
What is the vertebral level of the oesophageal hiatus?
T10
What structures go through the oesophageal opening?
Oesophagus, vagus nerve,left inferior phrenic vessels and the oesophageal arteries (from the left gastric arteries)
What are the two orifices of the stomach?
Cardiac opening and pyloric opening
What are the two curvatures of the stomach?
Greater and lesser curvatures
What are the two surfaces of the stomach?
Anterior and posterior
What is the pyloric sphincter?
A thickened ring of muscles
What is the function of the pyloric sphincter?
To control movement of contents from the stomach to the duodenum
What are the rugae formed from?
The mucosal layer of the stomach
In which parts of the stomach are the rugae most apparent?
Body and antrum
What structures form the stomach bed (posterior wall of the lesser sac)
Left dome of the diaphragm, pancreas, spleen, L. kidney, L. adrenal gland, colon, mesocolon and splenic artery
What is the effect of increased vagal stimulation on the pylorus?
It stimulates opening of the pylorus (relaxation)
Which group of lymph nodes will the 4 primary nodes eventually drain into?
Coeliac group
What is the effect of increased vagal stimulation on gastric secretion?
Stimulation of watery secretion
What are the three parts of the small intestine?
Duodenum, jejunum and Ileum
Which part of the small intestine receives the opening of the bile and pancreatic duct?
Duodenum (2nd part)
How is the duodenum peritonised?
Retroperitoneal
How is the jejunum peritonised?
Intraperitoneal
How is the ileum peritonised?
Intraperitoneal
What are the characteristics of the jejunum?
Deep red in colour, thick/heavy wall, greater vascularity, long vasa recta, large loops of arcades, little fat in the mesentery and large/tall circular folds
What are the characteristics of the ileum?
Pale pink, thin/light wall, little vascularity, short vasa recta, short loops of arcades, more fat in the mesentery and no circular folds
Which part of the autonomic nervous system stimulates the reduction of secretions and motility of the intestine and acts as a vasoconstrictor?
Sympathetic
How is the large intestine structure different to the small intestine?
Shorter/wider, no circular folds, microvilli and bands of muscle
How is the caecum peritonised?
Intraperitoneal
How is the ascending colon peritonised?
Retroperitoneal
How is the transverse colon peritonised?
Retroperitoneal
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 Iliac fossa
What is McBurney’s point?
1/3 of the distance from the anterior superior iliac sine to the umbilicus - most tender point in appendicitis as it is the common location of the base of the appendix
What is the role of the pelvic floor in maintaining faecal continence?
The muscles surround the anal canal and maintain tone keeping it closed
What other structures (besides the pelvic floor) are involved in faecal continence?
Internal and external sphincter
Which omentum are the hepatoduodenal and hepatogastric ligaments a part of?
Lesser omentum
What is the falciform ligament?
Ligament that attaches the liver to the anterior wall and separates the right and left lobes
What structure in the free edge of the falciform ligament is a remnant of an embryonic blood vessel?
Round ligament - umbilical vein
How many layers of peritoneum are present in the greater omentum?
Four
What function gives the greater omentum the name of abdominal policeman
It surrounds any inflamed/infected parts of the abdomen and prevents it spreading
What are the paracolic gutters?
Channels that run between the colon and abdominal walls
Where are the paracolic gutters located in relation to the large intestine?
Posterior to the large intestine alongside the ascending and descending colon
What is the clinical significance of the paracolic gutters?
They allow the accumulation and passage of infectious fluids between compartments
Name three abdominal viscera which lie in the free edge of the mesentery?
Small intestine (jejunum/ileum), large intestine (transverse/sigmoid) and mesoappendix
What muscle types form the muscularis externa of the oesophagus?
Upper 1/3 is skeletal
Lower 2/3 is smooth muscle
What kind of epithelium lines the oesophagus?
Non-keratinised stratified squamous epithelium
What type of muscle is the muscularis mucosae?
Smooth muscle
What are the layers of the oesophagus?
Mucosa, lamina propria, muscularis mucosae and muscularis externa
Which secretory cells are present in the gastric pits?
Chief cells (pepsinogen) and parietal cells (HCl and intrinsic factor) Goblet cells
What are the large folds that extend into the lumen of the small intestine?
Plicae
What are the finger like projections found in the small intestine called?
Villae
What type of epithelium lines the small intestine?
Simple columnar epithelium
What type of muscle is the muscularis mucosae of the small intestine?
Smooth muscle
What are the layers of the small intestine?
Surface epithelium,submucosa (lamina propria and muscularis mucosae) and muscularis externa
In which parts of the gut do the glands extend down beyond the muscularis mucosae?
Oesophagus and duodenum
What is the function of goblet cells?
Secretion of mucous
What is the transpyloric plane?
Transverse line 1/2 between the jugular notch and the upper border of the pubic symphysis
How do you locate the transpyloric plane on a patient?
Hand’s breadth below the xiphoid process
Which structures are present on the transpyloric plane?
Pylorus of the stomach, stomach, duodenum, pancreas, gallbladder and kidneys
How is the spleen peritonised?
Intraperitoneal
In which region of the abdominal cavity is the spleen located?
Left hypochondriac
Does the spleen move with respiration?
Yes
Name the structures in the hilum of the spleen
Splenic artery, splenic vein and gastrosplenic ligament
The tail of which organ is closely related to the hilum of the spleen?
Pancreas
What are the functions of the spleen?
Stores WBCs, recycles RBCs, haematopoiesis and phagocytosis
Is the pancreas an exocrine or endocrine gland?
Both
How is the pancreas related to the duodenum?
It is located in the curve of the duodenum
How is the pancreas peritonised?
Retroperitoneal
Which vein is formed posterior to the neck of the pancreas?
Hepatic portal vein
Into which part of the duodenum does the pancreatic duct open?
Duodenal papilla (2/3 of the duodenum)
What is the bare area of the liver bare of?
Peritoneum
Name 3 structures present in the porta hepatis?
R/L hepatic ducts, L/R hepatic arteries and portal vein
What fold of peritoneum is wrapped around the structures present in the porta hepatis?
Falciform ligament (visceral)
What structures are part of the extrahepatic biliary apparatus?
Hepatic ducts, common hepatic ducts, gallbladder, cystic duct and common bile duct
Where is bile stored?
Gallbladder
Where does bile enter the gut tube?
Duodenum
What is the function of bile?
Digestion and absorption of fat and fat soluble vitamins
What is Calot’s cystohepatic triangle?
Triangular space formed by the cystic duct, common hepatic duct and inferior surface - contains the cystic artery
What are the main histological features of the pancreas?
Islets of Langerhans, pure serous acini and small lobules surrounded by connective tissue septa
What are the main histological features of the liver?
Cells are arranged in sheets converging towards the centre and portal areas which contain the blood vessels and ducts
What are the two main parts of the spleen?
Red pulp and white pulp
What is the main content of the white pulp in the spleen?
Lymphocytes and macrophages
What is the main content of the red pulp in the spleen?
Vascular anastomoses and cords of cells
Which costal cartilage is the surface marking of the gallbladder?
9
Does the liver move with respiration?
Yes
Which ribs are related to the spleen?
9, 10 and 11 - midaxillary
Which abdominal plane crosses the pancreas and what part of the pancreas does it go through?
Transpyloric through the neck of the pancreas
