Salivary glands, Liver,Pancreas, Gall bladder

1. Digestive System -2
Dr.Anupama Marasini
Shree Birendra Hospital

2. ACCESSORY GLANDS
• Salivary glands
-3 pairs.They are:
a.Parotid gland
b.Sublingual gland
c.Submandibular gland

3. Parotid gland
• largest and most important
salivary gland (entirely serous
gland)
• located below the ear pinna
• duct of parotid gland is called
stenson’s duct

4. Sublingual gland
• smallest salivary glands
located below or base of
tongue
• opens by means of
several small ducts called
ducts of Rivinus

5. Submandibular gland
• one pair, present inside the
lower edge of the mandible
• drain their secretions through
wharton’s ducts
• contributes maximum (70%)
of volume of saliva

6. Saliva
• contains 99.5% of water, ions like
HCo3,Na,K,Cl etc, enzymes like ptyalin,
lingual lipas, antibacterial substance like
IgA, lysozyme, thiocyanates
• pH of human saliva : 6.8

7. Functions of Saliva
• binds the masticated food into a ‘bolus’ for
swallowing
• initiate fat digestion (by lingual lipase)
• initiate starch digestion ( by alpha
amylase)
• saliva contains IgA , lysozymes and
thiocyanates which kill the bacteria
• lubrication

8. Liver
• largest visceral organ and gland
of the body
• weigh about 1.2 to 1.5 kg in an
adult human
• situated in the right
hypochondrium
• Liver cells are called
hepatocytes.They have maximum
regenerative capacity
• Glissons capsule- capsule of liver

9. Liver
• divided into right and left lobes by falciform
ligament (fold of peritoneum)
• Right lobe forms 5/6th of the liver
• 4 lobes of liver
a.Right lobe
b.Left lobe
c.Caudate
d.Quadrate

10. Porta Hepatis
• deep, transverse fissure situated between
caudate and quadrate lobe
• contents are portal vein, hepatic artery and
common bile duct

11. Blood Supply
• liver receives 20% of its blood supply
through the hepatic artery and 80%
through the portal vein

12. Functions of liver
1.Metabolism of carbohydrates, fats and
proteins
2. Synthesis of bile which help in fat
digestion and prothrombin
3.Excretion of drugs, toxins,poisons,
cholesterol,bile pigments and heavy metals
4.Hemopoeisis- liver is the most important
site of RBC production in embryonic stage

13. 5.Synthesis of plasma proteins(
albumins,globulins)- all plasma proteins
except immunoglobins are produced by liver
6.Storage of glycogen,iron, fat,Vitamin A&D
7.Produces urea from ammonia (waste
product of protein metabolism) by ornithine
cycle

14. 8.Cori’s cycle- conversion of lactate into
glucose
9.Secretion of heparin- an anti-coagulant
10.Destruction of bacteria- by kupffer cells (
macrophage of liver)

15. Metabolism of carbohydrate
• Glycogenesis: In liver excess glucose are
withdrawn from the portal blood by liver
cells and converted into glycogen granules
for storage
• Glycogenolysis- when normal amount of
glucose in blood⬇️, liver cells convert
stored glycogen into glucose and release
into blood

16. Gluconeogenesis
• At the time of need, liver cells converts
non - carbohydrate compounds (
aminoacids, fatty acids and glycerol) into
glucose

17. Bile
• formed in liver
• human liver secretes about 0.5-1 ltr of bile
per day
• greenish yellow fluid formed in liver and
stored in gall bladder
• composed of water (98%) ,bile salts, bile
pigments, cholesterol, inorganic salts and
ions

18. Functions of Bile
• Absorption and emulsification of fat
• Absorption of Fat -Soluble vitamin -
Vitamin A,D,E,K
• Activation of pancreatic enzymes: bile
salts activate pancreatic lipase

19. Gall bladder
• pear shaped reservoir
of bile
• situated in the fossa on
the inferior surface of
the right lobe of liver

20. Functions of Gallbladder
• Storage of bile (30-50ml capacity), and its
release into the duodenum when required
• Absorption of water, and concentration of
bile

21. • Cystic duct- duct of gall
bladder
• joins with common
hepatic duct to form
common bile duct.
• bile duct joins with
pancreatic duct to form
hepatopancreatic duct
which opens at the
ampulla of Vater

22. Ducts of Pancreas

23. Pancreas
• an endodermally derived
mixed gland / heterocrine
gland /compound gland
• 99% exocrine and 1%
endocrine part

24. Pancreatic juice
• colourless, highly alkaline (pH -7.5 to 8.3)
and contains about 96%water and 4%
salts and enzymes
• is a complete digestive juice containing
digestive enzymes for carbohydrates,
proteins and fats

25. Pancreatic Enzymes
• Proteases
Trypsin,Chymotrypsin and
Carboxypeptidase:Proteins➡️Aminoacids
• Amylase
Starch and glycogen : Maltose

26. Lipases
converts complex fats to fatty acid and
glycerol

27. Peristalsis
• Wave of relaxation followed by contraction
which pushes the food forward
• it is an involuntary muscle relaxation and
contraction
• it occurs usually in esophagus , stomach
and intestine.
• Least peristalsis ocurs in rectum

28. Peristalsis
• Stimulation of parasympathetic nervous
system results in increase of gut
peristalsis
• Reverse peristalsis in stomach produces
vomiting
• Peristalsis also occurs in ureter, vas
deferens and fallopian tube

29. Lets practice some questions
1.Which enzyme is present in saliva
a.Lipase
b.Amylase
C.Pepsin
d.Peptidase

30. 2.Intrinsic factor is related to
a.Vit B1
b.Vit B6
c.Vit B9
d.Vit B12

31. 3.Spleen is present in
a.Rt. hypochondriac region
b.Lt. hypochondriac region
c.Lt. lumbar region
d.Rt.lumbar region

32. 4.Opening of parotid duct is via
a.Wharton’s duct
b.Stenson’s duct
c.Duct of wirsung
d.None

33. 5.Chief cell in stomach secrete
a.Hcl
b.Pepsinogen
c.Mucus
d.Trypsin

34. 6.Emulsification of fats takes
place in (License)
a.Oeshophagus
b.Stomach
c.Rectum
d.Intestine

35. 6.Stomach converts food into
semi digested food called
a.Bolus
b.Chyme
c.Chyle
d.Glucose

36. 7.Length of GI tract
a.2-4 m
b.4-6 m
c.6-8 m
d.8-10 m

37. 8. Production of glucose from
pyruvate in liver is
a.Glycolysis
b.Glycogenolysis
c.Gluconeognesis
d.Glycogenesis

38. 9.Gall bladder is for
a.Secretion of bile
b.Storage of bile
c.Storage of urine
.Production of WBC

39. 10.Which of the following does
not take part in
digestion(loksewa)
a.Larynx
b.Oesnophagus
c.Pharynx
d.Stomach

40. 11.Which is the largest gland of
body(Loksewa)
a.Spleen
b.Kidney
c.Eye
d.Liver

42. Portal Circulation
• The hepatic portal vein carries 75-80% of
the hepatic blood flow and hence is crucial.
It is not a true vein as it does not conduct
blood directly to the heart.
• It supplies veins with metabolic substrates.
• It also ensures that food ingested is
processed by the liver first before entering
the systemic circulation. This way, ingested
toxins are detoxified by hepatocytes.
• It also ensures that the liver is the first organ
to absorb nutrients after the intestines.