describe about the structure and function of stomach.

1. sanitha

2. The stomach is a J-shaped organ
that digests food. It produces
enzymes (substances that create
chemical reactions) and acids
(digestive juices). This mix of
enzymes and digestive juices
breaks down food so it can pass to
your small intestine
Stomach

3. stomach has five distinct sections/Parts:
1.The cardia
is the top part of your stomach. It
contains the cardiac sphincter, which prevents food
from traveling back up your esophagus.
2.The fundus
is a rounded section next to the
cardia. It's below your diaphragm (the dome-
shaped muscle that helps you breathe).

4. 3.The body (corpus)
is the largest section of your stomach.
In the body, your stomach contracts and begins to mix
food.
4.The antrum
lies below the body. It holds food until
your stomach is ready to send it to your small intestine.
5.The pylorus
is the bottom part of your stomach. It
includes the pyloric sphincter. This ring of tissue controls
when and how your stomach contents move to your small
intestine

5. Layers of muscle and other tissues make up your
stomach:
Mucosa is your stomach’s inner lining. When
your stomach is empty, the mucosa has small
ridges (rugae). When your stomach is full, the
mucosa expands, and the ridges flatten.
Sub mucosa contains connective tissue, blood
vessels, lymph vessels (part of your lymphatic
system) and nerve cells. It covers and protects the
mucosa.

6. Muscularis externa is the primary muscle of
your stomach. It has three layers that contract
and relax to break down food.
Serosa is a layer of membrane that covers your
stomach.

7.  Ant- Left lobe of liver& ant.abdomnal wall
 Post-abdominal aorta . Pancreas. Spleen . Left kidney
and adrenal gland
 Sup- Diaphragm esophagus and left lobe of liver
 Inf-Transverse colon and small intestine
 To the left- diaphragm and spleen
 To the right- Liver and duodenum

8.  Stomach continues with esophagus at the cardiac
sphincter
 Duodenum at the pyloric sphincter
 Curves….
Lesser curvature(lies the post surface of
the stomach. Downward continue with esophagus post.
wall )
Greater curvature(Just before pyloric
sphincter curves upward and form j shape )

9. Arterial
left gastric artery (br of coeliac artery)
right gastric artery and gastro epiploic
artery
Venous drainage
left gastric vein
right gastric vein joins to portal vein

10. Gastric juice is a unique combination of
hydrochloric acid (HCl), lipase, and pepsin. Its main
function is to inactivate swallowed microorganisms, thereby
inhibiting infectious agents from reaching the intestine.
About 2 lit of gastric juices secrete daily & Consists of
1. Water and Minerals (secreted by gastric glands)
2.Mucus secreted by mucus cell on stomach wall
3.HCL and intrinsic factor (By parietal cell of gastric
gland)
4.pepsinogen

11.  Always small quantity of juice present in the stomach.
Fasting juice
 Secretion reaches max. after 1hr of meal and declining
the level after 4 hrs
 3 phases of secretion
 Cephalic ….. Before food reaches the mouth by
stimulation of Vagus nerve (para .sym) sight or smell
of the food
 Gastric…..stimulated by presence of food. Entero
endocrine cells in the pylorus and duodenum secretes
gastrin

12.  Partially digested food reaches the intestine 2 hormones
secreted by endocrine cell in the mucosa secretin and
cholecystoinin
 They slow down the secretion of gastric juice and
gastric motilty

13. 1.Water… Liquefies the food swallowed
2.HCL….Stop the action of salivary amylase.
Kill the ingested microbes
Provide acid envt
3.Pepsin for protein digestion
4. Intrinsic factors for absorption of Vit. B
5.Mucus prevent the mechanical injury

14.  Chemical digestion
 Mechanical break down of food
 Limited absorption of water alcohol
 Non specific defence against microbes
 Preparation of iron substances
 Regulation of the passage of gastric content into
duodenum