This is a morpho anatomy project with simple explanation for digestive parts and their relevant functions.

3. Digestion

6. • MOUTH OR
BUCCAL
CAVITY
• PHARYNX
• ESOPHAGUS
• STOMACH
• SMALL
INTESTINE
• LARGE
INTESTINE
• ANUS

8. • PANCREAS
• LIVER
• GALL BLADDER

10. INNER LINING
IT HAS MUCUS
EPITHELUM CALLED
AS LAMINA PROPRIA.
PLICAE MEANS FOLDS
FUNCTION :- IT
HELPSIN
ABSORBTION AND
SECRETION.

11. IT LIES OUTSIDE
MUCOSA
THICK LAYER
OFLOOSE
CONNECTIVE
TISSUE WITH
BLOOD VESSESL
AND NERVE
ENDINGS.

12. IT HAS SMOOTH
MUSCLE
INNER SMOOTH
MUSCLE IS
CIRCULAR
OUTER LAYER IS
LONGITUDINAL
FUNCTION:- IT
CONTROLLS
MOVEMENT AND
SECRETION

13. IT IS SMOOTH
EPITHELIAL
LAYER
IT IS THE OUTER
LAYER
THUS CALLED AS
ADVENTITIA

14. • The digestive system includes the gastro-intestinal tract (mouth to anus) and
the glandular organs.
• Human digestive system is in the ventral cavity of human body.
• This system serves to transfer organic molecules, salts and water from the
external environment to the body’s internal environment.

15. • Most of the food taken into the mouth are large particles containing
macromolecules such as polysaccharides , fats , lipids and proteins.
• As such they cannot be absorbed by the intestinal wall. They must be
dissolved and broken down into much smaller molecules.
• This process is named as digestion.
• Digestion is accomplished by substances called enzymes produced from the
digestive glands.
• The enzymes are biocatalysts in the food breakdown process.

16. • SALIVARY AMYLASE
BY SALIVARY
GLANDS
• TRYPSIN ,
CHYMOTRYPSIN ,
PANCREATIC
AMYLASE ,
PANCREATIC
LIPASE ETC BY
EXOCRINE
PANCREAS
• ENTEROPEPTIDASE
, LACTASE ,
MALTASE ,
SUCRASE ETC BY
INTESTINAL
MUCOSA

17. LIPS
CHEEKS
TEETH
TONGUE
SALAIVARY GLANDS
2

18. • The first part is mouth.
• This is also called as buccal cavity or oral cavity .
• Lips surround the orifice of the mouth , cheeks are the side walls , tongue is at the
floor and the hard and soft palates are the roof .

19. • Lips are very sensitive and are very easily irritated .
• Upper lip has groove called as philtrum .
• When the libs are closed , the line of contact is known as the oral fissure.

20. • Cheeks are the lateral bountaries of the oral cavitiy.
• They are formed by a muscle is called as buccinater muscle

21. • Palate separates nasal cavity from oral cavity.
• There are hard and soft palates.
• Soft palate is which forms partition between Mouth and naso pharynx .
• Hard palate is made up of our bones.
• At the end of hard palate, there hangs a cone shaped process called uvula.

23. • Tongue is made up of skeletal muscle and covered by a mucuos membrane.
• The muscle of the tongue is called as Intrinsic muscle.
• Both origin and insertion of intrinsic muscle is tongue itself.
• During Mastication , the contraction of intrinsic muscle assist in the placement of food
between teeth.
• Tongus has another muscle called as Extrinsic muscle.
• Example of an Extensic muscle is genioglussus.
• It is inserted in theHyoid bone of the skull.

24. • These muscles help during Swallowing or deglutititon
and speech .
• Upper tongue is usually covered by elevations called
as Papillae .
• There are three types of Papillae
- Valalte
- Fungiform
- Filiform

25. • They have taste buds on their upper surface which can
distinguish the tastes like sweet, sour, bitter, salty, and umami.
• Lingual Frenulum helps to anchor tongue to the floor of the
mouth.
• Folds of mucuos membrane called Plica fimbriata extend towards
the either side of the Lingual Frenulum
• This regions helps in the absorption of certain drugs like
Nitroglycerin.

26. • Parotid
• Sublingual gland
• Submandibular gland

27. There are three types of major salivary
-Parotid
-Submandibular
-Sublingual
They are tubule alveolar in nature.
About 1 liter saliva is secreted every day

28. • They are the largest of all salivary glands.
• They produce watery serous type of saliva which does not have mcous.
• They are located between skin and masseter muscle below external ear.
• They open into mouth piercing Buccinater muscle .

29. • They are called mixed salivary glands because they produce both serous and mucous
saliva.
• They are just located below the mandibular angle .
• They open into mouth near lingual frenulum
• They are the smallest salivary gland.
• They open into the floor of the mouth

30. • Saliva also serves to lubricate the food bolus.
• Saliva is also hypotonic and alkaline.
• It is important to neutralize any gastric secretions that reflux into the esophagus.
• The saliva also has some antibacterial action.
• It facilitates swallowing and also keeps the mouth moist.
• It helps in speech also.

31. • CROWN
• NECK
• ROOT

32. • They are the organs of mastication.
• They cut , tear , grind the ingested food so that the ingested food mix well with saliva
and swallowed.
• A typical tooth has a crown .
• This is covered by enamel – the hardest substances in the body .
• The neck of the tooth is comparatively narrow.
• The root of the tooth is covered by Peridontal membrane and anchored to the alveolar
process

33. • It is to be noted that the tooth is covered by dentin and cementum
other than enamel.
• The dentin consists of a pulp cavity.
• Pulp cavity consists of connective tissue blood vessels lymphatic
vessels and sensory nerves.
• Twenty deciduous or baby teeth is later replaced by 32 permanent
teeth .
• There are four kinds of teeth
• Canine
• Incisor
• Molar
• Premolar

34. • The bolus from the buccal cavity is pushed into the Pharynx.
• The bolus actually moves into the oropharynx.
• Pharynx is actually divided into three.
• Nasopharynx
• Oropharynx
• Laryngopharynx
• As the bolus passes Pharynx , it enters Esophagus.

35. • Esophagus is a muscualar tube extends from Pharynx to stomach.
• It pierces Diaphram , a thin sheet an descends down into abdominal cavity.
• The lumen is actually lined by Stratified squamous epithelial cells.
• The esophagus opens into stomach by cardiac sphincter.
• The food moves by peristaltic action of the esophagus.
• The Esophagus has two sphincters
o Upper esophageal Sphincter
o Lower esophageal Sphincter
• Lower Esophageal Sphincter is also called as the Cardiac Sphincter

36. • Fundus
• Body
• Pylorus

37. • The stomach lies at the upper part of the abdominal cavity.
• The stomach actually posses three divisions
• Fundus
• Body
• Pylorus
• The curveformed by the upper right curvature is the Greater curvature.
• The curve formed by the lower left stomach is the Lesser curvature

38. • The Stomach has sphincters
 Lower Esophageal Sphincter (or) Cardiac Sphincter
 Pyloric Sphincter
• Phyloric Sphincter control the flow of food between Stomach and the small
intestine (Duodenum)
• The Epithelial lining of the stomach is thrown into folds called as Rugae.
• The respective depressions are called as Gastic Pits.
• There are numerous coiled-glands called as Gastric galnds

39. • PANCREAS
• LIVER
• GALL BLADDER

40. • The liver is the largest gland in the body.
• It is essential for life because it conducts a vast array of biochemical and
metabolic functions.
• An important function of the liver is to serve as a filter be- tween the blood
coming from the gastrointestinal tract and the blood in the rest of the body.

41. • PARIETAL CELLS
OR OXYNTIC
CELLS
• CHIEF CELLS
• ECL CELLS OR
ENTEROCHROMA
FFIN LIKE CELLS

42. • THIS IS ALSO
CALLED AS
OXYNTIC CELLS.
• THIS SECRETES
HYDROCHLORIC
ACID AND
INTRINSIC
FACTORS.
• IT IS STIMUATED
BY
NEUROTRANSMI
TTER RELEASED
FROM ENTERIC
NERVE.

43. • THIS IS ALSO
CALLED AS
ZYMOGEN
CELLS.
• THIS SECRETES
PEPSINOGENS.
• IT IS
STIMUATED BY
NEUROTRANSMI
TTER RELEASED
FROM ENTERIC
NERVE.

44. However mucus is also
secreted on the surface
of Epithelium. So acid
won`t damage the
inner layer

45. • IT IS ALKALINE IN
NATURE.
• IT CONTAINS
WATER, MINERAL
SALTS AND A
VARIETY OF
ENZYMES LIKE
TRYPSIN,
CHYMOTRYPSIN.
• PRECURSORS ARE
ACTIVATED BY
ENTEROKINASE.
• SECRETION OF
PANCREATIC JUICE
IS PRIMARILY
UNDER HORMONAL
CONTROL.

46. • IT IS ALKALINE IN
NATURE.
• BILE IS ONE OF THE
IMPORTANT
PANCREATIC
SECETION .
• SECRETIN
STIMULATES
PANCREATIC
SECRETION.
• THE GLUCURONIDES
OF THE BILE
PIGMENTS, BILIRUBIN
AND BILIVERDIN, ARE
RESPONSIBLE FOR
THE GOLDEN YELLOW
COLOR OF BILE..
• BILE SALT IS USUALLY
ABSORBED IN THE
SMALL INTESTINE.

47. • GASTRIN IS
SECRETED IN THE
GASTRIC MUCOSA.
• THEY STIMULATE
OYNTIC CELLS IN
PRODUCING
HYDRO-CHLRORIC
ACID.
• GASTRINS ARE
INAC- TIVATED
PRIMARILY IN THE
KIDNEY AND
SMALL INTESTINE

48. Small intestine has the following parts:
-duodenum
-jejunum
-ileum
Large intestine has the following parts:
-cecum
-colon
-rectum

49. When the food enters the intestine , it is called as chyme.
The pyloric sphincter located at the junction of stomach and duodenum
regulates movement of chyme.
The food in the small intestine is mixed with three juices namely bile
juice, pancreatic juice and intestinal juice.
The gastrointestinal system is the portal through which nutritive
substances, vitamins, minerals, and fluids enter the body.
Proteins, fats, and complex carbohydrates are broken down into
absorbable units (digested), principally in the small intestine.

50. The colon serves as a reservoir for the residues of meals that can- not be
digested or absorbed .
The ileum is linked to the colon by a structure known as the ileocecal valve.
It restricts reflux of colonic contents and the large numbers of commensal
bacteria into sterile ileum.
Each time a peri- staltic wave reaches ileocecal valve, it opens briefly,
permitting some of the ileal chyme to squirt into the cecum.

51. When food leaves the stomach, the cecum relaxes and the passage of
chyme through the ileo-cecal valve increases . This is actually a
vagal nerve reflex.
Then the undigested part reaches colon and then rectum.
Distention of the rectum with feces initiates reflex contractions of its
musculature and the desire to defecate.
Defecation is therefore a spinal reflex that can be voluntarily
inhibited by keeping the external sphincter contracted or facilitated
by relaxing the sphincter and contracting the abdominal muscles.

53. • The intestine has an unusual circulation.
• In that the majority of its venous outflow does not return
directly to the heart but rather is directed initially to the liver
via the portal vein.
• Innervation is by Enteric nerve and also vagus nerve.

54. AFFERENT NERVES
STIMULATE
EFFERENT NERVES
RESPONSE
BUT IN CASE OF
DIGESTIC SYSTEM ,
IT IS JUST TH E
OPPOSITE.
FOR EXAMPLE
SWALLOWING IS
INDUCED BY
AFFERENT NERVE

56. • Gastric and duodenal ulceration in humans is related primarily to a breakdown
of the barrier that normally prevents irritation and auto-digestion of the mucosa
by the gastric secretions.
• Infection with the bacterium Helicobacter pylori can also disrupts this barrier.
• Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) can also
inhibit the production of prostaglandins and consequently decrease mucus. Due
to decreased mucus , acid secreted can cause damage thus causing Peptic Ulcers.
• The NSAIDs are widely used to combat pain and treat arthritis.
• An additional cause of ulceration is prolonged excess secretion of acid due to
some diseases.

57. • Cholera is a severe secretory diarrheal disease that often occurs in
epidemics associated with natural disasters where normal sanitary
practices break down.
• The cholera bacillus stays in the intestinal lumen and it produces a
toxin.
• Because of the bacterial toxin , a series of reaction takes place thus
there is an increase in electrolyte and water content of the intestinal
contents causes the diarrhea.
• Oral ingestion of Glucose and salt (NaCl) and Cereals containing
carbohydrates are also useful in the treatment of diarrhea.

58. • Obesity is the most common and most expensive nutritional problem
everywhere in the world.
• Obesity is when BMI is more than 25.
• BMI is body mass index.
• It accelerates atherosclerosis, diabetes and many other body illness.
• Consumption of excess foods with abundant fat , doing a very less manual
work etc cause obesity.