Case 2 Flashcards
What is the resting volume of the stomach what is it’s maximum capacity?
1300m- 1500ml, capacity is 3L
What is the name for the inner concavity of the stomach?
The lesser curvature.
What is the name for the outer convexity of the stomach?
The greater curvature
What is the name for the angle on the lesser curvature of the stomach?
The incisura angularis
What are the four anatomical parts of the stomach?
The cardia, fundus, body/corpus and the pyloric part
What part of the stomach surrounds the cardial orifice at the top of the stomach?
The cardia
What is the name for the top dilated part of the stomach related to the left dome of the diaphragm?
The fundus
What part of the stomach lies between the fundus and the pyloric antrum?
The body/corpus
What are the two functional portions of the stomach?
the orad and caudad region.
What functional region of the stomach includes the fundus and the superior part of the body?
The orad
What functional region of the stomach contains the lower part of the corpus and the antrum?
the caudad
What is the name for the coarse in foldings of mucosa and submucosa throughout the inner surface of the stomach? Where are they most prominent?
rugae, they are most prominent in the proximal stomach
What is the name of the tall columnar mucous secreting cells which line the the whole gastric mucosa and gastric pits?
surface foveolar/mucous cells
What is the role of the mucous secreted by surface foveolar/mucous cells?
They protect the stomach lining from acid
Where are mucous neck cells found what is their role?
These cells are found deepish in the gastric pits and are thought to be progenitors of both the surface epithelium and cells of the gastric glands.
What type of cell found deepish in the gastric pits are thought to be the progenitors of the surface epithelial cells and gastric glands?
Mucous neck cells
Where are delta cells found what do they secrete what effect does this have?
they are found in stomach intestines and islets of langerhans, they secrete somatostatin which reduces gastrin and histamine release.
What cells does the somatostatin released by D/Delta cells act on what effect does it have?
G cells and ECL reducing gastrin and histamine release.
What are the three main types of gastric glands?
Cardiac tubular, main gastrin and pyloric(antral glands.
What is the name for the glands located in the mucosa of the cardia and secrete soluble mucous?
cardiac.
What are the three main types of cell in main oxyntic/gastric glands?
Chief/peptic cells, mucus neck cells and parietal/oxyntic cells
Where are the main gastric glands found?
In the body and fundus of the stomach.
Which cell type in the main gastric gland is basophilic?
Chief/peptic/zymogen cells
What do chief cells screte?
proteolytic proenzymes, pepsinogen I & II
Which type of cell found in the main gastric glands has a canalicular intracellular structure.
Parietal/oxyntic cells
What do parietal/oxytic cells secrete?
HCL and intrinsic factor
Where are parietal cells found in main gastric glands?
Mostly in the upper half
What are the two cell types of the pyloric/antral glands?
Mucus and G cells
pyloric/antral glands mostly contain which type of cell?
Mucous cells
What do G cells secrete?
gastrin
The serosa of the stomach is part of what structure?
The peritoneum
What are the three layers of musculature of the stomach from outer to innermost?
longitudinal, circular and inner oblique.
What two plexuses supply the stomach with its intrinsic innervation?
myenteric (auerbach’s) and submucoal (Meissener’s) plexuses
Where is the auerbach plexus located?
between the circular and longitudinal layers of the stomach.
Is it the intrinsic or extrinsic innervation that is responsible for peristalsis?
Intrinsic.
What aspect of the innervation of the stomach allows peristalsis in the antrum to influence the duodenal bulb?
The fact that the system for innervating the duodenum is continuous for those that innervate the stomach.
Where does the sympathetic innervation of the stomach arise how does it affect motility?
It arises from the coeliac plexus, it inhibits motility.
Where does the parasympathetic innervation of the stomach arise from, how does it affect motility?
It arises from the vagus nerve and stimulates motility.
where is the stomach relative to the peritoneum?
Intraperitoneal
What is the name of the specialized pacemaker cells located in the walls of the stomach, small intestine and large intestine?
cells of cajal
Where is the duodenum relative the the peritoneum?
It is retroperitoneal except at it’s beginning where it is connected to the liver via the hepatoduodenal ligament, a part of the lesser omentum
What are the four parts of the duodenum in order?
superior, descending, inferior and ascending.
Where does the superior part of the duodenum start and end? what are it’s relations?
It starts at the pyloric orifice and ends at the neck of the gall bladder. It is just right of vertebra L1, passes anteriorly to the gastroduodenal artery, portal vein and inferior vena cava.
Where does the descending part of the duodenum start and finish? What are its relations?
It starts at the neck of the gall bladder extending to the lower border of the L3 vertebra, Its anterior surface is covered by the transverse colon, behind it is the right kidney and is lateral to the head of the pancreas
Which of the four sections of the duodenum contains the major and minor duodenal papilla? What opens through these?
descending duodenum, the bile and pancreatic ducts open through the major papilla whereas the accessory duct opens to the minor papilla.
Which is the longest section of the duodenum?
The inferior part
What are the relations of the inferior part of the duodenum?
It crosses over the inferior vena cava, aorta and vetebral column and is crossed anteriorly by the superior mesenteric artery and vein.
What are the relations of the ascending part of the duodenum?
It is left of the aorta and alongside the vertebral column to roughly the L2 level.
Where does the duodenum end what surrounds this?
The duodenal flexure. It is surrounded by a fold of peritoneum containing muscle fibers know as the suspensory ligament or the ligament of Treitz
What are the cells of cajal attached to the smooth muscle of the stomach, large & small intestines via?
gap junctions and the myenteric plexus.
What does BER stand for?
Basal electrical rhythm
The cells of cajal undergo a rhythmic de and repolarization, at what voltage? What does this create?
From -65mV to -45mV this creates a slow wave known as the BER
What are the three meal related motor functions of the stomach?
Storage, mixing and slow emptying.
What are the two phases of a gastric slow wave?
Upstroke and plateau.
What is the standard rate of gastric slow waves?
3-4 waves per minute.
What are 5 agents that increase the smooth muscle contractile activity of the stomach?
ACh, gastrin, histamine, nicotine, barium and K+
What are 5 agents that inhibit stomach smooth muscle activity?
enterogastrone, epinephrine, norepinephrine, atropine and Ca2+
What is the name for the process by which the stomach expands as more food enters it? What reflex modulates this?
Receptive relaxation, it is mediated partly by the vagovagal reflex
What part of the brain related to swallowing sends a signal to the stomach when sending a bolus towards it?
The swallowing center of the medulla
What are the inhibitory neurotransmitters though to be responsible for receptive relaxation?
NO and VIP
Which of the the functional divisions of the stomach is responsible for the mixing function of the stomach?
The caudad region
What happens to the strength of constrictor waves of the stomach as they approach the pyloric antrum? What effect does this have?
They become stronger forcing the contents under higher pressure towards the pylorus.
What happens to the pylorus as stomach peristalsis approaches it what does his cause?
It contracts impeding emptying causing most antral contents to be retropulsed.
What is the normal mealemptying time of the stomach?
2-3 hours.