2. Stomach Flashcards
What are the functions of the stomach
- Stores ingested food- distension
- Mechanical digestion- peristaltic contraction churns contents
- Initial chemical digestion of proteins- secretion of gastric juice including acid and pepsinogen (→ pepsin, a protease)
- Secretion of intrinsic factor and gastroferritin for absorption of vitamin B12 and iron in more distal gut
- Regulated movement of food into the duodenum
- Endocrine function (eg. Gastrin)
Name the anatomical regions of the stomach
- Cardiac
- Fundus
- Body
- Pyloric- antrum and canal
- Physiology- orad and caudad areas
- Histology- different epithelium characteristics and secretory products in different areas
- Lower oesophageal sphincter (cardiac sphincter)
- Pyloric sphincter
- Cardiac notch
- Angular notch
- Greater Curvature
- Lesser Curvature
Describe the smooth muscle layers of the stomach
3 Layers- outer longitudinal, middle circular, inner oblique
Longitudinal layer- incomplete anteriorly and posteriorly
Oblique layer- incomplete along curvatures
Describe the internal anatomy of the stomach
The mucosal layer (both mucosa & submucosa) is quite folded, and these are known as gastric folds or rugae. These folds allow stomach to expand; if its distended then the folds disappear
Describe the surface anatomy of the stomach.
- Right Upper quadrant
- Right Lower Quadrant
- Left Upper Quadrant
- Left Lower Quadrant
Name the 9 regions of the abdomen
Right hypochondrium Epigastrium Left hypochondrium
Right lumbar (lateral/flank) Umbilicus Left lumbar (lateral/flank)
Right iliac fossa (inguinal/groin) Hypogastrium Left iliac fossa
Where is the superior plane located?
Transpyloric at L1/L2 discs //subcostal plane (lowest part of the ribs)
Where is the inferior plane located?
Interspinous (ASIS) // intertubercular (iliac tuberculum)
Where is the vertical plane located?
Semilunar (six pack) // midlinguinal // midclavicular
In which quadrants is the stomach located?
Stomach is located primarily in the upper left quadrant, but it extends into the right quadrant.
In which 9 regions is the stomach located
It is located in the left hypochondrium and epigastric regions
Stomach shape variable, but ends are relatively fixed.
Where is the Lower Oesophageal Sphincter Located? what is an alternative name for it?
(cardiac sphincter) in on the left side of vertebra T11; just interolateral (left side) of the xiphoid process and near the left 7th sternocostal joint.
Where is the Pyloric Sphincter Located?
to right of L1/L2 vertebrae (transpyloric plane)
What is the peritoneum?
The peritoneum is a thin membrane which lines the walls of the abdominal cavity and covers much of the viscera. The parietal peritoneum lines the walls of the cavity and the visceral peritoneum covers the viscera. Between the parietal and visceral layers of peritoneum there is a potential space (the peritoneal cavity). Abdominal viscera either are suspended in the peritoneal cavity by folds of peritoneum (mesenteries) or are outside the peritoneal cavity. Organs suspended in the cavity are referred to as intraperitoneal; organs outside the peritoneal cavity, with only one surface or part of one surface covered by the peritoneum, are retroperitoneal.
What is the mesentary?
peritoneal folds that attach viscera to the posterior abdominal wall. They allow some movemetna dn provide a conduit for vessels, nerves, and lymphatics to reach the viscera. The mesnntary is a large, fan shaped, double layered fold of peritoneum that connects the jejunum and ileum to the posterior abdominal wall.
What is the lesser omentum? What is it derived from?
Lesser omentum, including hepatogastric ligament (along lesser curvature) – derived from ventral mesentery.
• The lesser omentum is the double layer of peritoneum that extends from the liver to the lesser curvature of the stomach and the start of the duodenum.
What is the Greater Omentum? From where is it derived?
Greater omentum (along greater curvature) and gastrosplenic ligament – derived from dorsal mesentery
**Developmentally, stomach has dorsal and ventral mesenteries- then rotates 90 degrees
• The greater omentum is the large fold of visceral peritoneum that hangs down from the stomach. It runs from the greater curvature of the stomach, passing in front of the small intestines and reflects on itself to ascend to the transverse colon before reaching the posterior abdominal wall.
