1. 12. pH and quantity
1.1. Saliva
1.1.1. 6.8
1.1.2. 1.5 lit/day
1.2. Gastric juices
1.2.1. 1.5-2.0
1.2.2. 2-3 lit/day
1.3. Pancreatic juices
1.3.1. 7.8
1.3.2. 1.2 lit/day
1.4. Intestinal Juice
1.4.1. 7.8
1.4.2. 1.2 lit/day
2. 1. DIGESTIVE SYSTEM
2.1. Associated Glands
2.1.1. Salivary Glands
2.1.1.1. 6 in number (pairs)
2.1.1.2. Glands situated out buccal cavity but secrete in buccal cavity.
2.1.1.3. it's types
2.1.1.3.1. Parotid
2.1.1.3.2. Sub-mandibular or Sub-maxillary
2.1.1.3.3. Sub-lingual
2.1.1.4. Composition of Saliva
2.1.1.4.1. Release 1.5litre per day
2.1.1.4.2. ph = 6.8
2.1.1.4.3. contains 99.5% water
2.1.1.4.4. 0.5% solutes
2.1.2. Gastric Glands
2.1.2.1. fold of epithelial cells(mucosa) extends down into the lamina propria.
2.1.2.2. form columns of secretory cells
2.1.2.3. it's parts
2.1.2.3.1. Parietal/Oxyntic cells
2.1.2.3.2. Mucous Neck cells
2.1.2.3.3. Chief/Zymogen/Peptic cells
2.1.2.3.4. G cells
2.1.2.4. ROLE
2.1.2.4.1. Vitamin B12
2.1.2.4.2. HCl
2.1.2.4.3. Gastric juices
2.1.3. Pancreas
2.1.3.1. present between the limbs of duodenum
2.1.3.2. is a heterocrine gland
2.1.3.2.1. Exocrine/Acini
2.1.3.2.2. Endocrine/Islets of Langerhance
2.1.3.3. Ductus system
2.1.3.3.1. Duct of Santorini
2.1.3.3.2. Duct of Wirsung
2.1.3.4. Pancreatic juice
2.1.3.4.1. Release 1.2lit/day
2.1.3.4.2. ph = 7.8
2.1.3.4.3. Composition
2.1.4. Liver
2.1.4.1. largest exocrine gland of the body
2.1.4.2. Weight and position: 1.5 kg and upper right side of abdomen below diaphragm.
2.1.4.3. has high regenration power.
2.1.4.4. covering of unit of liver is called lobule and liver is called GLISSONS capsule (white-fibrous tissue).
2.1.4.5. Phagocytic cells in liver is called Kupffer cells
2.1.4.6. right and left lobes are separated by FALCIFORM LIGAMENT
2.1.4.7. unit of liver is benzene like structure called hepatic lobule.
2.1.4.8. removal of gall bladder is known as CHOLECYSTECTOMY
2.1.4.9. helps in detoxification of food
2.1.4.10. Composition of Bile juice
2.1.4.10.1. release 500-600 mL/day
2.1.4.10.2. 95% water
2.1.4.10.3. 5% cholestrol , Lecithin(phospholipid)
2.1.4.10.4. Bile-Salts
2.1.4.10.5. Bile-Pigments
2.1.4.10.6. enzymes are absent in bile juice
2.1.4.11. Ductous system
2.1.4.11.1. Common hepatic duct is combination of both right and left hepatic duct.
2.1.4.11.2. Duct originate from Gall bladder is called CYSTIC DUCT.
2.1.4.11.3. BILE DUCT is the combination of cystic duct and common hepatic duct
2.1.4.11.4. HEPATO-PANCREATIC DUCT is the combination of bile duct and duct of wirsung (pancreatic duct).
2.1.4.12. Sphincter
2.1.4.12.1. Sphincter of Boyden- present at cystic duct and common hepatic duct
2.1.4.12.2. Sphincter of ODDI- present at Ampulla of Vater (elongated structure before the sphincter).
2.1.4.13. PORTAL TRIAD
2.1.4.13.1. benzene like structure
2.1.4.13.2. hepatic vein is connected with portal triad with the help of HEPATOCYTES. Chain (network or canal/ canaliculli) of hepatocytes is called HEPATIC CORD. Cavity between heapatic cord is called SINSOID
2.1.4.13.3. Kupffer cells are present between hepatocytes(cellular level)
2.1.4.13.4. has six portal areas, 1 at each end
2.1.4.13.5. each has one portal triad and one at the center.
2.1.5. Intestinal Glands
2.1.5.1. Release intestinal juice (SUCCUS ENTERICUS) amount is 1L/day. whose pH is 7.8
2.1.5.2. Succus Entericus is fluid of
2.1.5.2.1. Brunner's Gland
2.1.5.2.2. Crypt of Lieberkuhn
2.1.6. HORMONALS REGULATION OF GUT SECRETION
2.1.6.1. Enterogastrone Hormone / gastric inhibitory peptide (GIP)
2.1.6.1.1. Source: Intestinal mucosa(duodenum)
2.1.6.2. Secretin
2.1.6.2.1. Acts on Duct of Santorini
2.1.6.3. Cholecystokinin (CCK) or CCK-PZ
2.1.6.3.1. acts on Duct of Wirsung
2.1.6.4. Duocrinin
2.1.6.4.1. Source: Intestinal mucosa(duodenum)
2.1.6.5. Enterocrinin
2.1.6.5.1. Source: Intestinal mucosa
2.1.6.6. Villi kinin
2.1.6.6.1. Source: Intestinal mucosa
2.2. Alimentary Canal or Gut
2.2.1. Fore-gut(Ectodermal)
2.2.1.1. Buccal Cavity
2.2.1.1.1. Teeth
2.2.1.1.2. Tongue
2.2.1.2. Pharynx
2.2.1.2.1. made up of skeletal muscles.
2.2.1.2.2. common passage for air and food.
2.2.1.2.3. It's function is deglutition. #first time fully developed found in ROUNDWORM.
2.2.1.2.4. divided in to three parts
2.2.2. Mid-gut(Endodermal)
2.2.2.1. Oesophagus
2.2.2.1.1. made up of two types of muscles
2.2.2.1.2. digestion and absorption, both are absent.
2.2.2.1.3. length is 22-25 centi-metre
2.2.2.1.4. Oesophagus above diaphragm has layer TUNICA ADVENTITIA.
2.2.2.1.5. Oesophagus below diaphragm has layer SEROSA.
2.2.2.2. Stomach
2.2.2.2.1. muscular, J-shaped organ.
2.2.2.2.2. stores food for 4-5 hours.
2.2.2.2.3. Inner folding inside stomach is called Gastric rugae.
2.2.2.2.4. It is located in the upper left portion of abdominal cavity.
2.2.2.2.5. It has 4 parts
2.2.2.2.6. Sphincters.
2.2.2.2.7. helps in churning movement.
2.2.2.3. Small Intestine.
2.2.2.3.1. length is 6 metre.
2.2.2.3.2. extends from pyloric sphincter to ileo-caecal valve.
2.2.2.3.3. It's types are
2.2.2.3.4. Structure present in complete small intestine.
2.2.3. Hind-gut(Ectodermal)
2.2.3.1. Large Intestine
2.2.3.1.1. plica and villi are absent
2.2.3.1.2. Digestion of food is absent
2.2.3.1.3. Haemorrhoid - Piles
2.2.3.1.4. Type
2.2.3.1.5. only absorption of water, minerals and some drugs takes place.
2.2.3.1.6. fermentation of undigested food occurs
2.2.3.1.7. secretion of mucus which helps in adhering the waste (undigested) particles together and lubricating it for an easy passage.
2.2.4. Different layer of GUT
2.2.4.1. Serosa
2.2.4.1.1. outer layer of gut and has two layers.
2.2.4.2. Muscularis externa
2.2.4.2.1. has two layers and both are smooth muscles. It helps in contraction of gut. (peristalsis)
2.2.4.2.2. EXCEPTION : In case of stomach there is a extra layer present (total 3) called :-
2.2.4.3. Sub-mucosa
2.2.4.3.1. have loose areolar connective tissue
2.2.4.3.2. contains nerves + Mucosa Associated Lumphoid tissue(MALT) + blood and lymph vessels.
2.2.4.4. Mucosa
2.2.4.4.1. inner layer of muscles
2.2.4.4.2. has GOBLET cells, which produce mucus.
2.2.4.4.3. made up of Areolar connective tissues / LAMENA PROPRIA
2.2.4.4.4. contains Mucosa Associated Lymphoid tissue (MALT) + blood and lymph vessels.
2.2.4.4.5. forms gastric glands in the stomach
2.2.4.4.6. forms intestinal glands, Crypts of Lieberkuhn in small intestine.
2.2.5. Nervous Regulation of Gut secretion and contraction.
2.2.5.1. Network Of Neurons
2.2.5.1.1. Aurbach Plexus
2.2.5.1.2. Meissners Plexus
2.2.5.2. Peripheral Nervous System(network of nerves which connects the spinal cord with body organs).
2.2.5.2.1. ANS
2.2.5.2.2. SNS
3. 2. PROCESS OF DIGESTION
3.1. Mechanical
3.1.1. Mastication in mouth
3.1.2. Churning in stomach
3.1.3. Peristalsis in Intestine
3.2. Biochemical
3.3. 1.Mastication of food
3.3.1. BOLUS = food+saliva
3.4. Degluition of food
3.5. Churning in stomach
3.5.1. acidic food in stomach called CHYME
3.5.2. alkaline food in intestine called CHYLE
3.6. Digestion of food
3.7. Absorption of food
3.8. Assimilation of food
3.9. Defecation
4. 3. DIGESTION OF PROTEINS
4.1. Activation of Zymogen in Gastric juices
4.1.1. In stomach PEPSINOGEN activated into PEPSIN at pH 1.8
4.1.2. PRORENIN activated into RENIN(Chymosin) at pH 1.8
4.1.3. In case of INFANT RENIN(Casein) is converted into PROCASEIN and this, in the presence of Calcium ions form Calcium-para Caseinate(curdling of milk).
4.2. Activation of Zymogen in Pancreatic juices
4.2.1. In intestine TRYPSINOGEN GET activated into TRYPSIN in the presence of ENTEROKINASE (Intestinal juice) at pH 7.8
4.2.2. CHYMOTRYPSINOGEN + PRO-CARBOXYPEPTIDASES activated in the presence of TRYPSIN to form CHYMOTRYPSIN and CARBOXYPEPTIDASES
4.3. Intestinal juices (Succus Entericus)
4.3.1. Enterokinase is present here which is a non-digestive enzymes
4.3.2. EREPSIN : Group of proteins (peptones + proteases) digestive enzyme in intestinal juice.
4.3.2.1. Amino peptidases
4.3.2.2. Dipeptidases
4.4. PROCESS
4.4.1. GASTRIC JUICE
4.4.1.1. with the help of this,Protein get break down into 3 types:- Protein, Peptones, Proteases.
4.4.2. PANCREATIC JUICE
4.4.2.1. Protein get break down into PEPTONES and PROTEASES with the help of TRYPSIN
4.4.2.2. PEPTONES and PROTEASES are converted into DIPEPTIDES with the help of CHYMOTRYPSIN and CARBOXYPEPTIDASES.
4.4.3. INTESTINAL JUICE
4.4.3.1. PEPTONES and PROTEASES left after action of pancreatic juice get converted into DIPEPTIDES with the help of Aminopeptides.
4.4.3.2. SUCCUS ENTERICUS acts at DIPEPTIDES to form Amino acids.
5. 4. DIGESTION OF STARCH
5.1. polymer of simple sugar
5.2. bond=Glycosidic bond
5.3. In salivary juice
5.3.1. Occur in mouth at pH= 6.8
5.3.2. 30% of starch digests here.
5.3.3. converts starch (polysaccharides) into Maltose(disaccharides)
5.3.4. Enzyme acting are salivary amylase (Ptyalin)
5.4. In Pancreatic juice
5.4.1. Occurs in duodenum
5.4.2. remaining 70% digests here
5.4.3. Starch is converted into Maltose
5.4.4. Enzyme acting are Pancreatic-amylase or Amylopsin
5.5. In Intestinal juice (Succus-Entericus)
5.5.1. release enzymes for digestion of Disaccharides
5.5.2. Maltose converted into Glucose + Glucose (monosaccharides) at pH 7.8
5.5.2.1. Enzyme MALTASE acts on it
5.5.3. Lactose converted into Glucose + Galactose at pH 7.8
5.5.3.1. Enzyme LACTASE acts on it
5.5.4. Sucrose (Invert sugar) converted into Glucose + Fructose (monosaccharides) at pH 7.8
5.5.4.1. Enzyme SUCRASE (INVERTASE) acts on it
6. 5. DIGESTION OF NUCLEIC ACID
6.1. It is a polymer of nucleotides
6.2. Bond = Glycosidic and Phosphodiester
6.3. in Pancreatic Juice
6.3.1. Nucleic acid get break down into Nucleotides in the presence of enzyme NUCLEASE (DNase and RNase).
6.4. in Intestinal Juice
6.4.1. Nucleotides get beak down into Phosphate and Nucleoside in the presence of Nucleotidase.
6.4.2. Phosphate get absorbed
6.4.3. Nucleoside get break down into sugar and nitrogenous base in the presence of enzyme nucleosidase.
6.4.4. Now sugar and nitrogenous base also get absorbed
7. 6. DIGESTION OF LIPID / FAT / TRIGLYCERIDES
7.1. helps in emulsification of fats
7.2. conversion of fat into fat droplets is emulsification
7.3. Bile also activates lipases
7.4. Glycerol + fatty acids = TRIGLYCERIDES (have ester bond)
7.5. Exception: If we ate emulsified fats then the digestion begins in mouth only
7.6. a. Emulsification of fats
7.6.1. In duodenum, BILE juice acts on fat molecule.
7.6.1.1. 1]. LECITHIN (phospholipid)
7.6.1.1.1. acts as surfactant
7.6.1.2. 2]. Organic salt
7.6.1.2.1. helps in activation of Lipase
7.7. b. Break down of TRIGLYCERIDES in doudenum
7.7.1. Triglycerides get break down into DIGLYCERIDES + MONOGLYCERIDES + FATTY ACIDS in the presence of PANCREATIC-LIPASE/ STEAPSIN
7.7.2. Diglycerides + Monoglycerides + Fatty Acids get converted into MONOGLYCERIDES + GLYCEROL + FATTY ACIDS & BILE SALTS in the presence of LIPASE (intestinal juice) .
7.8. c. Formation of micelles
7.8.1. Monoglycerides + Glycerol + fatty acids + bile salts combine to form Micelle. due to continuous contraction
7.8.2. 1st absorption occurs in epithelium, then in the presence of ribosome , monoglycerides converted into triglycerides and stored in the packet of protein called CHYLOMICRONE
7.8.3. 2nd absorption of Chylomicrone inside the Lacteal
7.8.3.1. absorption of fat soluble (VITAMIN A,D,E and K) occurs in Lymph capillary
7.8.3.2. absorption of water soluble (VITAMIN B and C) occurs in blood capillary
8. 8. TRANSPORTATION OF FOOD
8.1. Primary Active transportation
8.1.1. such proteins which helps in absorption of sodium ions
8.1.2. all +ve ions
8.1.3. ATP is used
8.2. Secondary Active transportation
8.2.1. absorption of Galactose , amino acid or Glucose along with two sodium ions
8.2.2. it is a sodium co-transport
8.2.3. ATP is used
8.3. Facilitated transportation
8.3.1. transfer of Fructose , amino acid or Glucose without ATP with the help of carrier protein
8.4. Simple Diffusion
8.4.1. Lipid , amino acid or Glucose transfer with simple diffuson
8.5. Osmosis
8.5.1. always water
8.6. Passive transport
8.6.1. all -ve ions like Cl- , HCO3-
8.7. IMPORTANT
8.7.1. GALACTOSE
8.7.1.1. only with Secondary active transportation
8.7.2. FRUCTOSE
8.7.2.1. only with FACILITATED TRANSPORTATION
8.7.3. LIPID
8.7.3.1. only with SIMPLE DIFFUSION
9. 9. CALORIFIC Value of Food
9.1. Fat
9.1.1. Physiological : 9 Kcal/gm
9.1.1.1. Gross Value: 9.45 Kcal/gm
9.2. Protein
9.2.1. Physiological : 4 Kcal/gm
9.2.1.1. Gross Value: 5.65 Kcal/gm
9.3. Carbohydrate
9.3.1. Physiological : 4 Kcal/gm
9.3.1.1. Gross Value: 4.10 Kcal/gm
10. 10. Nutrients Of Food
10.1. Macronutrients
10.1.1. Provide energy
10.1.2. Proximate principle
10.1.3. Ex: Carbohydrate , fats, protein
10.2. Micronutrients
10.2.1. provide protection
10.2.2. protective principle
10.2.3. Ex: Vitamins, minerals, cod liver oil
11. 7. ABSORPTION OF FOOD
11.1. Oral cavity
11.1.1. Alcohol
11.1.2. some drugs (Asprin or Disprin
11.2. Stomach
11.2.1. water + free glucose + simple sugars
11.2.2. Alcohol + some drugs (Asprin or Disprin)
11.2.3. some ions like Na+ , Fe2+ , etc
11.3. Small Intestine
11.3.1. Duodenum
11.3.1.1. maximum digestion
11.3.2. Jejunum
11.3.2.1. maximum absorption
11.3.3. Ileum
11.3.3.1. maximum absorption of Vitamin B12 and Bile salts
11.3.4. maximum absorption of water occurs here.
11.4. Large Intestine
11.4.1. water + minerals + certain drugs
12. 11. DISORDERS of Digestive enzymes
12.1. inflammation of intestinal tract due to bacterial or viral infections.
12.2. infections caused by parasites also like, tapeworm, roundworm, threadworm, hookworm, pinworm
12.3. JAUNDICE
12.3.1. Liver is affected
12.3.2. skin and eye turn yellow due to deposition of bile pigment
12.3.3. deposition occurs due to breakdown of haemoglobin
12.4. DIARRHOEA
12.4.1. abnormal frequency of bowel movement
12.4.2. increased liquidity of the faceal discharge
12.4.3. reduces absorption of food
12.5. CONSTIPATION
12.5.1. faeces are retained within colon
12.5.2. bowel movements occurs irregularly
12.5.3. prolong constipation leads to heamorrhid
12.6. VOMITING
12.6.1. ejection of stomach content through mouth
12.6.2. reflex action controlled by the vomit center in medulla oblongata
12.6.3. A feeling of nauea preceds vomiting
12.7. INDIGESTION
12.7.1. food is not digested leadig to a feeling of fullness
12.7.2. causes are inadequate enzyme secretion, anxiety, food poisoning, over-eating, and spicy food
12.8. PURGATIVES
12.8.1. Mg++ ions containing purgatives stimulate intestinal peristalsis and evacuation of fluid faeces.
12.8.2. Divalent are purgatives
12.9. Protein Energy Malnutrition (PEM)
12.9.1. are dietary deficiency of protein
12.9.2. MARASMUS
12.9.2.1. occurs only in infant(upto 1 year)
12.9.2.2. due to deficiency of food
12.9.2.2.1. fat
12.9.2.2.2. proteins
12.9.2.2.3. carbohydrtes
12.9.2.3. wasting of muscles
12.9.2.4. thin limbs and body
12.9.2.5. retardation in mental and physical growth
12.9.2.6. Oedema absent
12.9.3. KWASHIORKOR
12.9.3.1. present in children of (1-5)years
12.9.3.2. due to deficiency of proteins
12.9.3.3. wasting of muscles
12.9.3.4. thin limbs
12.9.3.5. retardation in brain and growth of the body
12.9.3.6. Oedema is present.