The document provides an overview of the structure and function of the digestive tract. It describes the main organs that make up the gastrointestinal tract, including the mouth, esophagus, stomach, small intestine, and large intestine. It discusses the four main layers of the digestive tract (mucosa, submucosa, muscularis, serosa) and provides details on specific diseases that can affect the digestive system, such as Crohn's disease, Hirschsprung disease, and leiomyoma.

1. SHISODIA HARSH VARDHAN SINGH
UNIVERSITY OF PERPETUAL HELP SYSTEM DALTA

2. INDEX
 Introduction
 Oral cavity
 Esophagus
 Stomach
 Small intestine
 Large intestine
 Quiz

3. INTRODUCTION
 series of hollow organs joined in a long, twisting tube
from the mouth to the anus.
 hollow organs that make up the GI tract
 GI tract are the mouth, esophagus, stomach, small
intestine, large intestine, and anus
 GI tract are the mouth, esophagus, stomach, small
intestine, large intestine, and anus

6. INTRODUCTION
structure within the digestive tract allow the following
–
 Ingestion
 Mastication
 Motility
 Secretion

7. Introduction
 Elimination
 Hormone releasing
 Chemical digestion
 Absorption

8. INTRODUCTION
 STRUCTURE OF DIGESTIVE TRACT –
- hollow tube with lumen of variable diameter.
- four main layer
* mucosa
* submucosa
* muscularis
* serosa

10. MUCOSA
 he mucosa is the innermost layer, and functions in
absorption and secretion. It is composed of epithelium
cells and a thin connective tissue.
 The mucosa contains specialized goblet cells that
secrete sticky mucus throughout the GI tract.

13. SUBMUCOSA
 the submucosa is the layer of dense, irregular
connective tissue or loose connective tissue that
supports the mucosa, as well as joins the mucosa to
the bulk of underlying smooth muscle (fibers that run
circularly within a layer of longitudinal muscle).

16. MUSCULARIS
 These muscles cause food to move and churn together
with digestive enzymes down the GI tract.
The muscularis externa consists of an inner circular l
ayer and a longitudinal outer muscular layer. ...
The muscularis mucosa is made up of smooth
muscle, and is most prominent in the stomach.

18. SEROSA
 Serous membranes line and enclose several body
cavities, known as serous cavities, where they secrete a
lubricating fluid to reduce friction from muscle
movements .

19. ORAL CAVITY
 Both physical and chemical digestion begin in
the mouth or oral cavity which is the point of entry
of food into the digestive system.
 Lined with stratified squamous epithelium .
 May be keratinized , non keratinized depending on
the locaton
 food is broken into smaller particles by mastication,
the chewing action of the teeth

20.  The tongue helps in swallowing—moving the bolus
from the mouth into the pharynx.

21.  Digestion of food begins in the mouth.
 Food is masticated by teeth and moistened by saliva
secreted from the salivary glands.
 zymes in the saliva begin to digest starches and fats.
With the help of the tongue, the resulting bolus is
moved into the esophagus by swallowing.

22. ORAL CAVITY
 TONGUE - A muscular organ located on the floor of
the mouth, is an extremely mobile structure .
 Lower surface of the tongue is smooth , with typical
lining of mucosa
 Tongue have papillae -
- filiform papillae
- fungiform papillae
- foliate papillae
- vallate

23. PAPILLAE
 FILIFORM PAPILLAE very numerous , elongated ,
chonical shape
- fine, small, cone-shaped papillae covering most of
the dorsum of the tongue .

24.  Fungiform papillae
- less numerous
- lightly kiratinized
- mushroom shaped
- with innervated cores of
lamina propia

25.  FOLIATE PAPILLAE –
several parallel ridge on each side of tongue
anterior to the sulcus terminalis
The foliate papillae are clustered into two groups
positioned on each side of the tongue, just in front of
the V of the vallate papillae.

27.  VALLATE PAPILLAE -
- largest papillae with diameter of 1 to 3 mm .
- 8 to 12 papillae , just inform of sulcus terminalis
- They lie near the back of the palatine section of
the tongue and are arranged in a V-shaped formation
directed toward the throat

30. TEETH

32. ESOPHAGOUS
 The esophagus is a muscular tube connecting the
throat (pharynx) with the stomach
 The esophagus is about 8 inches long, and is lined by
moist pink tissue called mucosa.
 The esophagus runs behind the windpipe (trachea)
and heart, and in front of the spine.

35. STOMACH
 muscular organ located on the left side of the upper
abdomen.
 receives food from the esophagus.
 food reaches the end of the esophagus, it enters
the stomach
 secretes acid and enzymes that digest food.

37.  muscles contract periodically, churning food to
enhance digestion.
 pyloric sphincter is a muscular valve that opens to
allow food to pass from the stomach to the small
intestine.

39. WALL OF THE STOMACH

40. GASTRIC PITS AND GLAND

41. LARGE INTESTINE
 also known as the large bowel
 last part of the gastrointestinal tract and of the
digestive system in vertebrates.
 Water is absorbed here and the remaining waste
material is stored as feces before being removed by
defecation

43. DISEASES OF
DIGESTIVE
TRACT

44. Chrohn disease
 inflammatory bowel disease (IBD).
 causes inflammation of your digestive tract
 Inflammation caused by Crohn's disease can involve
different areas of the digestive tract in different people.

45. SYMPTOMS
 last segment of the small intestine (ileum) is affected
 Diarrhea
 Fever
 Fatigue
 Abdominal pain and cramping

46.  Blood in your stool
 Mouth sores
 Reduced appetite and weight loss
 Pain or drainage near or around the anus due to
inflammation from a tunnel into the skin (fistula)

47.  Abdominal pain
 Blood in your stool
 Ongoing bouts of diarrhea that don't respond to over-
the-counter (OTC) medications
 Unexplained fever lasting more than a day or two
 Unexplained weight loss

49. HIRSCHSPRUNG DISEASE
 a birth defect
 absence of particular nerve cells (ganglions) in a
segment of the bowel in an infant.
 absence of ganglion cells causes the muscles in the
bowels to lose their ability to move stool through the
intestine (peristalsis).

50.  colonic aganglionosis
 congenital megacolon
 HAEC
 Hirschsprung-associated enterocolitis
 Hirschsprung’s disease
 HSCR
 intestinal aganglionosis
 megacolon, aganglionic

52. LEIOMYOMA DISEASE
 also known as fibroids
 smooth muscle tumor that very rarely becomes cancer
(0.1%)
 occur in any organ like uterus , small bowl and
esophagus etc.