The
former is located on the left, at the level of the tenth thoracic vertebra the
pyloric orifice lies at the level of the first lumbar vertebra. It is the
opening from where the food travels towards the duodenum. Given below is a
labeled diagram of the stomach to help you understand stomach anatomy. Cardiac
refers to the section of the stomach that is located around the cardiac
orifice. The lower esophageal sphincter lies at the junction where the
esophagus meets the stomach. It prevents the backflow of food from the stomach
to the esophagus. The funds lie above the cardiac orifice. It contains
swallowed air. It is located to the left and lies above the body of the
stomach, which is the large central section. The pyloric region of the stomach
is divided into pyloric tantrum, which is a funnel-shaped section that becomes
the pyloric canal while approaching the duodenum, the first section of the
small intestine. At the end of this canal lies the pyloric sphincter. This ring
of muscle fibers is responsible for regulating the movement of chime into the
duodenum. It determines the rate at which food moves from the stomach to the
duodenum.
The greater curvature is longer and convex in Soma Biotics shape, whereas the
lesser curvature is shorter and concave in shape. The greater curvature lies on
the left of the cardiac orifice, over the dome of the funds, and along the left
border of the stomach to the pylorus. The lesser curvature lies on the right.
It runs from the cardiac orifice to the pylorus. The greater momentum and the
lesser momentum divide the abdominal cavity into the greater sac and the lesser
sac. These are formed by two layers of peritoneum (one layer folded over it).
The presence of lymph nodes and immune cells in the greater momentum helps
fight gastrointestinal infections. The greater momentum basically hangs down
from the greater curvature of the stomach. On the other hand, the lesser momentum
is attached to the stomach and the liver, and is continuous and peritoneal
layers of the stomach and duodenum, which in turn combine at the lesser
curvature. The stomach lies in front of the lesser sac. Mucosa refers to the
inner lining of the stomach. Large, wrinkle-like folds called reggae lie in the
mucosa when the stomach is empty. These flatten as the stomach fills and the
stomach wall gets distended. It contains gastric glands, as well as pits.
The
mucosa is divided into the epithelial layer (non-ciliated simple columnar
epithelium), lamina propriety (layer of thin connective tissue), and muscular
is mucosa (thin layer of smooth muscle). Sub mucosa, which lies under the
mucosa, is made up of connective tissue. Under the sub mucosa lies muscular is external,
which consists of layers of smooth muscle. Muscular is external is composed of
an outer longitudinal layer, a middle circular layer, and an inner oblique
layer. It is the contraction of these muscle layers that helps in mixing,
churning, and breaking down food. The outer layer that covers the stomach is
called servos. It is fused and visceral peritoneum, and is composed of simple squalors
epithelium and areola connective tissue. On the surface of the mucosa, the
simple columnar epithelial cells or the goblet cells secrete mucus. The mucosa
also contains tubule-shaped gastric glands that secrete gastric juices and
mucus. Gastric pits, which are narrow channels in the stomach that act as
openings for the gastric glands, are also lined by the surface mucus cells.
Gastric juices are secreted by special types of exocrine glands. These include
neck mucous cells, chief cells, and parietal cells. The neck mucous cells secrete
mucus that has a more neutral pH than that secreted by the cells at the surface
of the stomach lining. The chief cells secrete pepsinogen, which is the
inactive precursor to a proteolysis called pepsin. The conversion of pepsinogen
to pepsin takes place in the lumen of the stomach, in the presence of gastric
hydrochloric acid.
The parietal cells secrete hydrochloric acid, which is a
highly corrosive acid. It is hydrochloric acid that is responsible for the low
environment in the stomach. The parietal cells also secrete intrinsic factor,
which is a glycoprotein that binds to vitamin B12 in the stomach and
facilitates its absorption in the small intestine. The G-cell, which is a type
of hormone-producing cell in the lining of the gastric pits, produces and
secretes a peptide hormone called gastric either on receiving a signal from the
vague nerve, or due to the rise in the gastric pH of the stomach or distension
of the stomach wall during a meal. Gastric also promotes the production of
hydrochloric acid by parietal cells. The stomach receives parasympathetic nerve
fibers from the vague nerves and sympathetic fibers from the celiac ganglia. It
must be noted that sensory vigil fibers play a role in gastric secretion. There
are three phases of gastric secretion, which include the cephalic phase,
gastric phase, and the intestinal phase. In the cephalic phase, parasympathetic
reflexes are triggered due to the smell, sight, taste, or even thoughts about
food. The gastric phase occurs and the entry of food into the stomach and the
consequent rise in the pH and distension of the wall of the stomach. The
intestinal phase commences as food enters the duodenum. It is characterized by
the secretion of intestinal gastric. During this phase, acid in the upper
section of the small intestine triggers a sympathetic reflex, which in turn
inhibits the secretion of gastric juice from the stomach wall.
The left gastric
artery is the narrowest branch of the celiac. It passes upward and runs to the
left to reach the food pipe. Then, it runs down along the lesser curvature of
the stomach. It provides blood to the upper right section of the stomach, as
well as the lower section of the food pipe. The right gastric artery arises
from the hepatic artery. Running to the left of the stomach's lesser curvature
and the pyloric end of the stomach, it joins the left gastric artery. This
artery provides blood to the lower right section of the stomach. The short
gastric arteries supply blood to the funds. The left gastroepiploic and the
right gastroepiploic arteries provide blood to the upper and the lower section
of the greater curvature of stomach, respectively. The veins of the stomach
correspond to the aforementioned arteries. While the right and left gastric
veins drain into the portal vein, the short gastric veins and the left
gastroepiploic vein return blood into the splendid vein. The right
gastroepiploic vein returns blood into the superior mesenteric vein. On a
concluding note, the main functions of the stomach include storage and mixing
of food into chime, and the passage of chime into the duodenum. The cells in
the stomach lining secrete gastric juices, and the maximum secretion taking
place an hour after a meal. Problems can arise if the secretion of gastric
juices or the wave-like muscle contractions approximately 60% of pancreatic
cancers occur in the head of the pancreas, while the rest 40% are detected in
the body and tail areas.
When talking about the digestive system, the first
things that comes to our mind are the stomach, along and the small and large
intestines. However, another organ that is often not talked about a lot, but
forms an inseparable part of the digestive system, is the pancreas. This organ
produces pancreatic juice, and out which, we would have had a hard time digesting
food. Moreover, malfunctions involving the pancreas may lead to the onset of
chronic ailments, one example being diabetes. The pancreas is a soft, grayish-pink
J-shaped glandular organ that lies in the abdominal region at the rear of the
stomach. It is around 12 to 15 cm long and 4 cm wide, and sits across the
lumbar spine. The head of the pancreas resides and in the curve of the
duodenum, the first section of the small intestine. This organ that is guarded
by the rib cage plays a crucial role in aiding digestion. The rubbery gland
secretes that promote the breakdown of fats, proteins, and carbohydrates in
simpler forms to facilitate their absorption. Another important function of the
pancreas is to release the insulin hormone, which assists in controlling blood
sugar. Anatomy of the Human Pancreas The shape of the pancreas resembles that
of a tadpole; hence, anatomically, it can be divided into 4 sections―the head,
neck, body, and the tail.
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