details about digestive system and diseases

1. Anatomy & Physiology OF
HARISHANKAR SAHU
B.PHARMA FINAL YEAR
SRIP,KUMHARI
BY-
Digestive System

2. Organs of the Digestive System
 Mouth
 teeth
 Salivary glands
 Pharynx
 Esophagus
 Stomach
 Liver
 Gallbladder (GB)
 Pancreas
 Small intestine
 Large intestine
 Rectum
 Anus

3. Main Functions
Digesting food
– Physical and chemical breakdown of large food into
molecules: glucose, triglycerides, amino acids
Absorbing nutrients
– From intestines
– Circulated through the body by cardiovascular system
Eliminating waste
– Any food that cannot be digested or absorbed is expelled

4. Oral Cavity (mouth)
• Roof is palate
– Hard – bony anterior
– Soft – flexible
posterior
• Hanging down from
soft palate is uvula
– Speech production
– Location of gag reflex

5. Oral Cavity
• Cheeks are lateral
walls
• Lips are anterior
opening
• Entire cavity lined
with mucous
membrane

6. Oral Cavity
• Digestion begins when food enters mouth
– Mechanically broken up by chewing
• Tongue moves food within mouth
• Mixes with saliva
– Digestive enzymes
– Lubricates
• Taste buds on tongue surface
– Detect bitter, sweet, salty, sour flavors

7. Processes of the Mouth
 Mastication (chewing) of food
 Mixing masticated food with saliva
 Initiation of swallowing by the tongue
 Allowing for the sense of taste

8. Salivary Glands
• Produce saliva
– Prevents bacterial
infection
– Lubrication
– Contains salivary
amylase
• Breaks down starch

9. Three pairs of Salivary Glands
• Parotid – lateral side of face, anterior to ear, drain by parotid duct
to vestibule near 2nd upper molar
• Submandibular – medial surface of mandible – drain near lingual
frenulum drain posterior to lower molars
• Sublingual – in floor of mouth - drain near frenulum

10. Function
 Mixture of mucus and serous fluids
 Helps to form a food bolus
 Contains salivary amylase to begin
starch digestion
 Dissolves chemicals so they can be
tasted

11. Teeth
 The role is to masticate (chew) food
 Humans have two sets of teeth
1. Deciduous (baby or milk) teeth
 20 teeth are fully formed by age two
2. Permanent teeth
 Replace deciduous teeth beginning between the ages
of 6 to 12
 A full set is 32 teeth, but some people do not have
wisdom teeth

12. Classification of Teeth

13. Pharynx Anatomy
 Nasopharynx – not part of
the digestive system
 Oropharynx – posterior to
oral cavity
 Laryngopharynx – below
the oropharynx and
connected to the
esophagus

14. Pharynx Function
 Serves as a passageway for air and food
 Food is propelled to the esophagus by two
muscle layers
 Longitudinal inner layer
 Circular outer layer
 Food movement is by alternating contractions of
the muscle layers (peristalsis)

15. Esophagus
 10 inches long in adults
 Food enters from pharynx
 Runs from pharynx to stomach
through the diaphragm
 Conducts food by peristalsis
(slow rhythmic squeezing)
 Passageway for food only
(respiratory system branches off
after the pharynx)
Joins stomach at cardiac orifice*
Cardiac sphincter at cardiac orifice to
prevent regurgitation (food coming back up
into esophagus)

16. Stomach
• Lies mostly in LUQ
– But pain can be epigastric or
lower
• Just inferior to (below)
diaphragm
• Anterior (in front of) spleen
and pancreas
• Tucked under left lower margin
of liver
• Anchored at both ends but
mobile in between
• Capacity: 1.5 L food; max
capacity 4L (1 gallon)
16
epigastrium
junction
with
esophagus
funnel shaped
contains
pyloric
sphincter
dome

17. 17

18. Stomach
• J-shaped; widest part of alimentary canal
• Temporary storage and mixing – 4 hours
– Into “chyme”
• Starts food breakdown
– Pepsin (protein-digesting enzyme needing acid
environment)
– HCl (hydrochloric acid) helps kill bacteria
– Stomach tolerates high acid content but esophagus doesn’t
– why it hurts so much when stomach contents refluxes
into esophagus (heartburn; GERD)
• Most nutrients wait until get to small intestine to be
absorbed; exceptions are:
– Water, electrolytes, some drugs like aspirin and alcohol
(absorbed through stomach)
18

19. Stomach Functions
 Acts as a storage tank for food
 Site of food breakdown
 Chemical breakdown of protein begins
 Delivers chyme (processed food) to the
small intestine
 It secretes intrinsic factor which is
necessary for the absorption of vit.B12

20. Small intestine
• Longest part of alimentary canal (2.7-
5 m)
• Site of greatest amount of digestion
and absorption
• Small intestine has 3
subdivisions
– Duodenum – 5% of length
– Jejunum – almost 40%
– Ileum – almost 60%
• Modifications
– Circular folds or plicae circulares,
villi, lacteal, microvilli
• Cells of mucosa
– Absorptive, goblet,granular,
endocrine

21. • Small intestine designed for absorption
– Huge surface area because of great length
– Structural modifications also increase absorptive area
• Circular folds (plicae circulares)
• Villi (fingerlike projections) 1 mm high – simple columnar epithelium: velvety
• Microvilli
*
Absorptivie
cell with
microvilli to
increase
surface area
& many
mitochondria:
nutrient
uptake is
energy-
demanding

22. Villi of the Small Intestine
 Fingerlike
structures formed
by the mucosa
 Give the small
intestine more
surface area

23. Microvilli of the Small Intestine
 Small projections
of the plasma
membrane
 Found on
absorptive cells
Figure 14.7c

24. Structures Involved in Absorption of Nutrients
 Absorptive cells
 Blood
capillaries
 Lacteals
(specialized
lymphatic
capillaries)

25. Digestion in the Small Intestine
Pancreatic enzymes play the major digestive
function
 Help complete digestion of starch (pancreatic
amylase)
 Carry out about half of all protein digestion
(trypsin, etc.)
 Responsible for fat digestion (lipase)
 Digest nucleic acids (nucleases)
 Alkaline content neutralizes acidic chyme

26. Absorption in the Small Intestine
 Water is absorbed along the length of the small
intestine
 End products of digestion
 Most substances are absorbed by active
transport through cell membranes
 Lipids are absorbed by diffusion
 Substances are transported to the liver by the
hepatic portal vein or lymph

27. Large Intestine
 Larger in diameter,
but shorter than the
small intestine
 Frames the internal
abdomen
 Digested residue
reaches it Main
function: to absorb
water and
electrolytes

28. Structures of the Large Intestine
 Cecum – saclike first part of the large intestine
 Appendix
 Accumulation of lymphatic tissue that sometimes becomes
inflamed (appendicitis)
 Hangs from the cecum
 Colon
 Ascending
 Transverse
 Descending
 S-shaped sigmoidal
Rectum = Rectum is area for storage of feces
Leads to the anus, the external opening of the alimentary canal
Defecation

29. Functions of the Large Intestine
 Absorption of water
 Eliminates indigestible food from the
body as feces
 Does not participate in digestion of food
 Goblet cells produce mucus to act as a
lubricant

30. Food Breakdown and Absorption in
the Large Intestine
 No digestive enzymes are produced
 Resident bacteria digest remaining
nutrients
Produce some vitamin K and B
Release gases
 Water and vitamins K and B are absorbed
 Remaining materials are eliminated via
feces

31. Accessory Organs of the Digestive
System
Gallbladder
Liver
Pancreas

32. The Liver
• Largest gland in the body
(about 3 pounds)
• Over 500 functions
• Inferior to diaphragm in
RUQ and epigastric area
protected by ribs
• R and L lobes
– Plus 2 smaller lobes
• Falciform ligament
– Mesentery binding liver to
anterior abdominal wall
• 2 surfaces
– Diaphragmatic
– Visceral
• Covered by peritoneum
– Except “bare area” fused to
diaphragm
32

33. 33

34. Functions of the Liver
• Bile production
– Salts emulsify fats, contain pigments as bilirubin
• Storage
– Glycogen, fat, vitamins, copper and iron
• Nutrient interconversion
• Detoxification
– Hepatocytes remove ammonia and convert to urea
• Phagocytosis
– Kupffer cells phagocytize worn-out and dying red and white blood cells,
some bacteria
• Synthesis
– Albumins, fibrinogen, globulins, heparin, clotting factors

35. Role of the Liver in Metabolism
 Several roles in digestion
 Detoxifies drugs and alcohol
 Degrades hormones
 Produce cholesterol, blood proteins
(albumin and clotting proteins)
 Plays a central role in metabolism

36. Gallbladder
• Bile is produced in the liver
• Bile is stored in the gallbladder
• Bile is excreted into the duodenum when needed (fatty meal)
• Bile helps dissolve fat and cholesterol
• If bile salts crystallize, gall stones are formed
– Intermittent pain: ball valve effect causing intermittent obstruction
– Or infection and a lot of pain, fever, vomiting, etc.
36
*

37. Figure:- The Gallbladder

38. Pancreas
 Produces a wide spectrum
of digestive enzymes that
break down all categories
of food
 Enzymes are secreted into
the duodenum
 Alkaline fluid introduced
with enzymes neutralizes
acidic chyme
 Endocrine products of
pancreas
 Insulin
 Glucagons

39. Pancreas
• Anatomy
– Endocrine
• Pancreatic islets produce
insulin and glucagon
– Exocrine
• Acini produce digestive
enzymes
– Regions: Head, body, tail
• Secretions
– Pancreatic juice
(exocrine)
• Trypsin
• Chymotrypsin
• Carboxypeptidase
• Pancreatic amylase
• Pancreatic lipases
• Enzymes that reduce DNA
and ribonucleic acid

40. Processes of the Digestive System
 Ingestion – getting food into the mouth
 Propulsion – moving foods from one region of the
digestive system to another
 Peristalsis – alternating waves of contraction
 Segmentation – moving materials back and forth to aid in
mixing

41. Processes of the Digestive System
 Mechanical digestion
 Mixing of food in the mouth by the tongue
 Churning of food in the stomach
 Segmentation in the small intestine
 Chemical Digestion
 Enzymes break down food molecules into their
building blocks
 Each major food group uses different enzymes
 Carbohydrates are broken to simple sugars
 Proteins are broken to amino acids
 Fats are broken to fatty acids and alcohols

42. Processes of the Digestive System
 Absorption
End products of digestion are absorbed in
the blood or lymph
Food must enter mucosal cells and then
into blood or lymph capillaries
 Defecation
Elimination of indigestible substances as
feces

44. DISORDERS OF THE
GASTROINTESTINAL SYSTEM

45. Disorders of the upper GI system
Disorders affecting Ingestion
• ANOREXIA: lack of appetite, could be from emotional or
physical factors
• lab tests may be done to assess nutritional status
• Medical treatment:supplements may be ordered, TPN or
enteral feedings
• Nursing Interventions:
– oral hygiene, clean room, determine cause of
nausea and treat, include family and
friends(socialization), respect likes and dislikes,
education

46. STOMATITIS
• Inflammation of the oral mucosa (mouth)
• Causes: trauma, organisms, irritants, nutritional
deficiency, diseases, chemotherapy
• S/S: swelling, pain, ulcerations, excessive salivation,
halitosis, sore mouth
• Treatment:
• pain relief, removal of causative factor, oral hygiene,
medications, soft bland diet

47. GINGIVITIS
• Inflammation of the gums
• Causes: poor oral hygiene, poorly fitting
dentures, nutritional deficiency
• S/S: red, swollen, bleeding gums, painful
• Treatment: dental hygiene, prevention of
complications

48. HERPES SIMPLEX TYPE 1
• Infection affecting the lips and mucous membranes
of the mouth
• Causes: Herpes simplex virus
• S/S: Vesicles on the mouth, nose or lips, malaise,
edema of surrounding area
• Treatment: Antiviral medication(Zovirax), analgesics,
symptomatic relief
• Nsg Interventions: Administer meds, keep lesions
dry, provide symptomatic relief

49. LEUKOPLAKIA
• Abnormal thickening and whitening of the
epithelium of the mucous membranes of the cheeks
and tongue
• Causes: Chronic irritation
• S/S: Thickened white or reddish lesions on the
mucous membrane, lesions can not be rubbed off
• Treatment: May be surgically removed or treated
with chemotherapy, meticulous oral hygiene
• Interventions: Assess mouth frequently, assist with
oral hygiene, discuss removal of sources of irritation

50. ORAL CANCER
• Malignant lesions may develop on the lips, oral cavity, tongue
and pharynx. Generally squamous cell carcinomas
• Causes: high alcohol consumption, tobacco use, external
irritants
• S/S: Leukoplakia, swelling, edema, numbness, pain
• Diagnosis: biopsy
• Treatment:
– Surgery
– Radiation or chemotherapy
• depends on the size and location and the lesion
• Interventions: consult MD for special mouth care, monitor
respiratory status, keep HOB elevated, administer pain med,
assess ability to swallow and talk, assess for infection at
incision site, education.

51. ESOPHAGITIS
• Inflammation or irritation of the esophagus
• Causes: Reflux of stomach contents, irritants, fungal
infections, trauma, malignancy, intubation
• S/S: heartburn, pain, dysphagia
• Treatment: treat underlying cause
• Interventions: soft bland diet, administer meds,
elevate HOB, observe for complications

52. NAUSEA AND VOMITING
• Nausea: unpleasant sensation usually preceding vomiting,
may have abdominal pain, pallor, sweating, clammy skin
• Causes: irritating food, infection, radiation, drugs,
hormonal changes, surgery, inner ear disorders, distention
of the GI tract
• Vomiting: forceful expulsions of stomach contents through
the mouth. Occurs when vomiting reflex in the brain is
stimulated.
• Projectile vomiting- is forceful ejection of stomach
contents.
• Regurgitation- gentle ejection of stomach contents without
nausea or retching

53. Complications and Treatment
• May lead to dehydration, metabolic
alkalosis, aspiration
• Treatment: Antiemetics( Phenergan,
Dramamine, Scopolamine patch Reglan), IV
fluids, NG tube, TPN
• Nursing care: through assessment, keep
patient comfortable, offer liquids, position
on side, suction setup in the room

54. GASTRITIS
• Inflammation of the lining of the stomach
• ACUTE: excessive intake of food or alcohol.
Food poisoning, chemical irritation
• CHRONIC: repeated episodes of acute, H Pylori

55. Signs/Symptoms and Complications
• Nausea, vomiting, feeling of fullness, pain in
stomach, indigestion. With chronic may have
only mild indigestion
• changes in stomach lining with decrease in
acid and intrinsic factor
( high risk for pernicious anemia)

56. Treatment
• Treat symptoms, and fluid replacement
• Medications: antacids, H2 receptor blockers, B 12
injections, corticosteroids analgesics, antibiotics if H
Pylori
• bland diet, frequent meals
• Eliminate the cause
• surgical intervention
• BEST DIAGNOSIS IS GASTROSOPY & BIOPSY

57. PEPTIC ULCER
• Loss of tissue from the lining of the digestive
tract. May be acute or chronic.
• Classified as gastric or duodental (stress-
develop 24-48hr. After event)
• CAUSES: drugs, stress, heavy alcohol and
tobacco use, infection (H .pylori bacteria)
Conditions that cause high gastric acid
concentration

58. TREATMENT
• Drug therapy
– Antacids
– H2 RECEPTOR BLOCKERS
– ANTICHOLINERGICS-Pro-Banthine, Robinul, Bentyl
– SUCRALFATE- Carafate
– Antibiotics –Flagyl, tetracycline, Biaxin
• treatment goals- relieve symptoms, promote healing,
prevent complications and recurrence

59. STOMACH CANCER
• Rare(25,000/yr.), common in males, African American, over
70 and low socioeconomic status. 60% decrease in past 40
yrs.
• No S/S in early stages
• Late stages S/S: N/V, ascities, liver enlargement, abd. Mass
• Mets to bone and lung
• 10% survival rate after 5 yrs.
• Risk factors: pernicious anemia, chronic gastritis, cigarette
smoking, diet high in starch, salt, salted meat, pickled
foods, nitrates
• Treatment: surgery/ chemotherapy/ radiation
– subtotal gastrectomy, total gastrectomy

60. OBESITY
• Increase in body weight, 20% over ideal,
caused by excessive fat. Morbid obesity twice
ideal
• Causes: heredity, body build, metabolism,
psychosocial factors. Calorie intake exceeds
demands.
•

61. Treatment and nursing care
• Weight reduction diet
• drug therapy, mainly Amphetamines
• Surgical procedures:
– Liposuction
– Lipectomy
– Jaw wiring
– Intragastric balloon
– Gastric bypass
– gastroplasty
– jejunoileal bypass
• Nursing care-assessment, diet monitoring, education

62. DIRRHOEA
• The passage of loose liquid stools with
increased frequency, associated with
cramping, abd, pain
• Causes; (many), foods, allergies, infections,
stress, fecal impaction, tube feedings,
medications
• Complications- usually temporary/ can be
dehydration, malnutrition

63. Treatment/Nursing care
• Treatment; GI rest, antidiarrheal
drugs(Lomotil, Imodium, Kaolin, Aluminum
hydroxide)
• Nursing Care: help determine cause, assessVS,
weight, skin turgor, abdominal destention,
perianal irritation, skin integrity

64. CONSTIPATION
• HARD DRY INFREQUENT STOOLS PASSED WITH
DIFFICULTY
• Causes: (many),inactivity, ignored urge,
drugs,age related changes
• Complications: straining (Valsalva maneuver)
and fecal impaction

65. Treatment/Nursing care
• Laxatives, suppositorys, enemas for prompt
results
• stool softeners, increase fluids,dietary fiber
• Nursing care: assessment, monitor fluids and
diet, education, check for impaction

66. Thank
you…