ABSORPTION OF DIGESTED FOOD
The process through which the food stuff diffuses through the intestinal mucous membrane and reaches the blood, is termed as absorption. The process of absorption in different parts of the alimentary canal takes place in the following manner.
Absorption in Buccal- Cavity :-No absorption of food takes place in the oral and the oropharyngeal cavity. Only some chemicals/medicines and alcohol are absorbed in oro pharyngeal cavity.
Absorption in stomach :-In the stomach, absorption of water, some salts, alcohol, glucose and few drugs like Aspirin takes place, complete absorption of alcohol takes place in the stomach.
Absorption in duodenum – Iron & calcium ion are absorbed in the duodenum.
Absorption in jejunum – Maximum absorption take place in jejunum.
Millions of microscopic folds or finger like projections are present in the lumen of gut which are called villi, villus is unit of absorption.
These villi are supplied with a network of blood capillaries and Lymphatic capillaries. Largest of which is central Lacteal. The cells that line the surface of villi numerous microscopic bristle like projections are called microvilli or brush border. These further increase the surface area for the absorption of the nutrients/digested food.
On the surface of the mucous epithelium are billions of single cell (Unicellular) mucous glands called mucous or goblet cells. These cells mainly secrete mucus that acts as a lubricant and protects the epithelial surface from damage and digestion.
The lining cells of the villi are columnar epithelial cells called enterocytes. On the surface of enterocytes, numerous microvilli are found, they increase the surface area of mucous membrane.
Digestion and absorption of Carbohydrate
The principal carbohydrate of our food is usually starch (from rice or wheat) which is broken down by the pancreatic amylase. Disaccharides are broken down to their monosaccharide by enzymes of the succus-entericus.
Monosaccharides are absorbed via the capillary blood within the villus to finally reach into portal vein.
Absorption of glucose molecules occurs along with Na+ by active symport (Co-transportation) and Fructose is absorbed Facilitated diffusion, because constration of glucose is higher in cells where as concentration of fructose is low in cells.
Digestion and absorption of amino acid –
All these proteins are exposed to pepsin, trypsin, chymotrypsin, carboxypeptidases etc and as a result they are converted into tri and dipeptides or free amino acids. Amino acid are of two types L-amino acid & D-amino acid.
The L-amino acids are naturally occuring & are absorbed by active process against the concentration gradient while D–amino acid are absorbed passively by diffusion.
Di–and tripeptide enter the enterocytes where they are hydrolyzed to amino acids by peptidases and then absorbed via portal blood.
Digestion and absorption of Fat –
One molecule of triglyceride is hydrolyzed into one molecule of monoglyceride and two molecules of fatty acids by pancreatic lipase.
After hydrolysis, the bile salt, monoglyceride and the fatty acid together produce a complex called a mixed micelle.These are water soluble & enter in the enterocytes. Monoglyceride and fatty acid are resynthesized with in enterocyte to form a molecule of triglyceride (TG). TG combines with a small amount of protein and resultant complex is called chylomicron(150mm, white). Chylomicron enters the lacteal
Fat soluble vitamins are absorbed along with dietary fat whereas water soluble vitamins are absorbed by passive diffusion. Vit. B12 is absorbed with intrinsic factor by forming a complex.
In ileum Vit. B12 & Bile salt are absorbed. In colon only water is absorbed.
All lymph- capillaries coming out of the alimentary canal unite to form Lymph- vessels. All lymph - vessels coming from the alimentary canal open into the Left Thoracic Lymph Duct. This duct now opens into the Left Subclavian vein. Through the blood, fats reaches the heart and from here it is distributed throughout the body.
Besides fats, other substances of the digested food like- sugars, amino- acids, vitamins, minerals- salts after being absorbed, enter the blood capillaries. All blood- capillaries coming out of the alimentary canal, join together to form the Hepatic portal vein. This vein takes the digested food material into the liver. From the liver, the Hepatic vein and the superior post - caval vein takes them to the heart. Heart distributes them throughout the body . Liver performs some necessary and important actions on the digested food.
Maximum water absorption occurs from upper part of small intestine passively.
Absorption in colon :-
Colon absorbs water from the undigested food. Due to Haustra the water - absorbing surface of colon increases and it efficiently increases absorption of water.
The excreta of rabbit is given out of the body in the form of small Pellets. The process of removal of undigested food from the body is termed as the Defecation. The process of Defecation is involuntary in rabbit, though it is voluntary in most animals.
Symbiotic bacteria found in colon. Bacterias synthesise vitamin-K, B1, B2 etc.
Undigested food goes into rectum where it gets converted into faeces contains – water and solid matter. Solid matter contains dead bacteria 30%, fat 10-12%, proteins 2-4% and others. These faeces ejected outside through anus.
In the morning the excreta of rabbit is in the form of semi-solid pellets. It has more amount of undigested cellulose in it. Cellulose is a colloid substance, Colloids have the capacity to bind water on their surface, so complete absorption of water is not possible in intestine, to completely digest the cellulose rabbit again ingests the semi-solid excreta so again digestion of cellulose takes place in the caecum.
In the evening the excreta of rabbit is in the form of solid, dry pellets. These have less amount of undigested cellulose in them. This nature of rabbit to eat is own excreta is termed as Coprophagy or Caecotrophy or also Pseudorumination. Double circulation of food through the alimentary-canal is termed as Caecotrophy.
Food of rabbit mainly consists of cellulose so this activity is necessary for rabbits.
Brown colour of the excreta is due to 2 pigments - Stercobilin and Urobilin. Both of them are formed due to the degradation of Bilirubin. Foul smell of the excreta is due to Indole, Scatole and Tryptophan. CH4, NH3, H2S. These are found in the colon due to the decomposition of amino-acids by bacteria.
Pellets of rabbit don't have a foul smell because it has a minimum amount of protein in its diet. Carnivores have excess protein-rich diet so their excreta is highly foul-smelling.
SUMMARY OF ABSORPTION OF DIFFERENT NUTRIENTS
Large intestine secretes mucus which adhere to undigested food makes it lubricated, so it further passes smoothly from rectum to anus.
Compound stomach/ Ruminant stomach
Stomach of Ruminant animals made of 4 chambers :
Rumen (paunch) → largest
Reticulum (honey comb) → Smallest
Abomasum (Rennet) → true stomach
Gastric juice-secreted by Abomasum. So it is called true stomach. Inner surface of Rumen and Reticulum lined by Keratinised epithelium. Symbiotic bacteria found in Rumen and Reticulum. Voluntary muscles found in Rumen and Oesophagus. Hence reverse peristalsis are found in Rumen and oesophagus which is controlled by will power of animal. Omasum is absent in Camel and Deer.
Caloric value :
The amount of heat liberated from complete combustion of 1 gm food in a bomb calorimeter (a closed metal chamber filled with O2) is its gross calorific value or gross energy value (G.C.V.).
The actual amount of energy liberated in the human body due to combustion of 1 gm of food is the physiologic value (P.V.) of food.
G.C.V. (in K.cal/gm)
P.V. In K.cal/gm)
ASSIMILATION OF ABSORBED FOOD
Amino acids are not stored but are taken up by the cells in connection with the synthesis of proteins. Proteins are used for growth, repair, etc. Excess amino acids can be converted into glucose and then to fat and are thus stored. This is an irreversible reaction. Amino acids can also be converted to glucose and used as fuel for the cell. During their conversion to glucose the amino acids are deaminated (removal of amino groups –NH2).The liver is chief site for deamination, i.e, a process by which the amino group is removed from the amino acid resulting in the production of ammonia. The ammonia is soon converted into urea, which is filtered from the blood in the kidney.
The excess of the monosaccharides; the glucose, fructose and galactose are usually stored in the liver and muscle cells in the form of glycogen(glycogenesis). Whenever, there is a deficiency of glucose in the blood the glycogen is converted into glucose(glycogenolysis). Muscle glycogen is utilized during muscle contraction. Glucose is utillized in the production of energy for various body activities. A considerable amount of glucose is converted into fat and stored as such.
The fat is stored in the fat deposite of the body. Such as subcutaneous layers, mesenteries etc. The fat stored is a readily available source of fuel for the cells. Fat has important insulting properties in connection with the conservation of heat and maintenance of body temperature. Fat also plays a protective role as filling or around packing material and between organs. In the liver phospholipids are formed which are returned to the blood to be used by all the cells. In the liver cells the fats are converted into amino acids and carbohydrates. Vitamins, salts and water are also useful for various metabolic processes.
The elimination of faeces from the alimentary canal is called egestion or deflection.
Peristalsis gradually pushes the indigestible meterials of the small intestine into the large intestine or colon. Normally 1500 ml of chyme passes into the large intestine per day. The colon absorbs most of the water. It also absorbs electrolytes, including sodium and chloride from the chyme. The epithelial cells of the colon also excrete certain salts such as iron and calcium from the blood.
Escherichia coli (bacterium) lives in the colon which feeds on undigested matter. This bacterium, in turn produces vitamin B12 (cobalamin), vitamin K, vitamin B1, (thiamine), and vitamin B2 (riboflavin) that are absorbed by the wall of the colon. Consequently, the chyme converted into semi solid faeces.
As the pellets of faeces enter the rectum, distension of rectal wall induces the feeling of defecation due to a defecation reflex. This reflex initiates peristalsis in the last part of the colon (sigmoid colon) and the rectum, forcing the faeces towards anus.
As the faeces reach anus the anal sphincters relax to allow its discharge (defaecation). The external anal sphincter is under voluntary control whereas the internal anal sphincter is involuntary relaxation of the internal anal. In infants the defaecation occurs by reflex action without the voluntary control of the external anal sphincter.
PROTEIN ENERGY MALNUTRITION
It is a protein deficiency disease. It commonly affects infants and children between 1 to 3 year of age.
Symptoms – Underweight, stunted growth, poor brain development loss of appetite anaemia, oedema on lower leg and face.
Cure –Proteins are necessary for growth, repair of tissue and for body defence therefore adequate amount of proteins must be present in the diet.
Daily requirement – 1 gm protein per kg. body weight in adults. 2 gm protein per kg body weight in growing children.
Sources in food –Cereals pulses, meat, fish, milk, groundnuts, peas, leafy vegetables etc.
Marasmus – It is caused by protein-energy-malnutrition(PEM) or deficiency of protein and total food caloric value. It mainly occurs in the age group of one year in newly born baby.
Symptoms – Impairs physical growth, subcutaneous fat disappears, ribs become very prominent, limbs become thin and skin becomes dry, thin & wrinkled. There is no oedema on leg and face but loss of weight occurs.
Cure – Diet with adequate proteins and proper caloric value should be given to the infants Source in food – Same as kwashiorkor.
Hypercholesterolemia (Overnutrition) – It is caused due to intake of excess of saturated fat such as butter, ghee, red meat, egg. Cholesterol level in blood rises abnormally (hypercholesterolemia) this may cause thrombosis and heart attack.
Obesity (Overnutrition) – It is caused by excessive intake of high caloric nutrients such as sugar, honey and saturated fat. Fat accumulates in the tissue. This may cause high blood pressure, diabetes and heart diseases. Regular exercise and taking of green leafy vegetables are recommended to such persons.
Hypervitaminosis (Overnutrition) – It is caused by excessive intake of vitamins. Such as excess of vitamin D causes deposition of calcium in soft tissue. Excess of vitamin A causes lack of appetite, itching rash etc. Hypervitaminosis of 'D'-Nausea, a anorexia, hypercalcaemia, hyperphosphatemia, calcification of soft tissue.
Fluorosis – It is caused by excessive intake of fluorine. It is characterised by mottled (brownish discolouration) teeth.
Constipation - Because of show reaching of excreta into the large-intestine hard and dry excreta deposits in the colon.
Diarrhoea - Fast and rapid removal of excreta from the large-intestine is called Diarrhoea. It may be due to viral or bacterial infection in the intestine.
Types of Food Relative to their Nature of Nutrients and Basic Functions
Sugar, glucose, sugarcane, honey and milk
’wheat, bread, maize, com, rice and potatoes
Butter, sunflower oil, seeds and vegetable oils, ruts, almonds, cheese, liver oils and egg-yolk
Eats and oil
flesh (neat, chicken, fish), milk, pulses, cereals, egg (albumen and yolk) and cheese
Table sits, pickles and butter
Table salts, pickles and butter
Jaggery, banana, date and potato
Milk, cheese, curd, fish, axp, pulses, carrot, cabbage and dark green leaves
Meat, fish, milk, cheese, eggs, pulses and cereals;
meat, liver, egg-yolk, find, green Issues, ruts, and pulses
Sea-fish, sea-veed, canyon and iodised table salt (sea food)
Gcd and shark liver oil, liver, kidneys, egg-yolk, green and yellow vegetables, (carrot, mango, lettuce, cabbage), tomato, yeast, milk and hitter
Whole cereals, dried beans, pork meat, egg-yolk, yeast
Meat, liver, fish, mdlk, egg, cheese, legumes and green leafy vegetables
Pulses, cereals, net, liver, fish, intestinal bacteria and yeast (Also synthesised in the human body from the amino acid, tryptophan )
PP'(pellagra preventing or nicotinamide)
Citrus fruits, vegetables, tomato, and papers
C (Ascarbic acid)
Ood and dark liver oil, chicken, egg-yolk, milk, butter,
etc. (Also synthesised in human skin in presence of sunlight.
SOME IMPORTANT MINERAL,THEIR EFFECT OF DEFICIENCY AND FUNCTION
Effect of deficiency
Rickets, muscular spasm (Vitamin - D is also required)
Component of bone and teeth; Essential for normal blood clotting; needed for normal muscle and nerve function, and Heart function (Vitamin - D is also required),
Anorexia, muscular cramp
Principal anion of interstitial fluid; Important in formation of HCl and acid-base balance,
Muscle convulsion in intestine
Enzyme activator. Required in muscle relaxation, Ribosome binding and nerve function
Goitre, Abortion, infant death, Cretinism
Component of thyroid hormone.
Anaemia, weak immunity
Components of respiratory pigments (like haemoglobin and myoglobin), respiratory enzymes (like cytochromes) and oxygen transport enzymes.
Deformation of bone and teeth, Retarded body growth and physiological function
Important structural component of bones, DNA and RNA; essential in energy transfer, storage of energy (ATP) and other metabolic activities; maintains normal blood pH (buffer action.)
Rickets, Fisk of paralysis
Principal cation in the cytoplasm; controls nerve excitability and muscle contraction. Dietary deficiency causes rickets among children.
Muscular cramp, Hypotension and Anorexia
Principal cation of interstitial fluid; maintains fluid balance; essential for conduction of nerve impulse. Component of bile salt, helps in absorption of glucose, fructose and few amino acid..
Skin patches, disturb metabolism
Components of hormones (e.g. insulin) ; necessary for normal metabolism and present in amino acid like methionine, cysteine.
Weak immunity and fertility, Fetartedgrowth and Anorexia
Component of at least 70 enzymes, like carbonic anhydrase, and some peptidases.
Anemia and damage of CNS
Component of enzymes for melanin synthesis; Essential for haemoglobin synthesis. Component of cyt-a3 in ETS (Cytochrome oxidase).
Component of Vitamin - B and erythropoiesis.
Diabetes mellitus and Irregular ATP production
Normal activity of insulin, carbohydrate and lipid metabolism
Mile infertility, prostate cancer, liver necrosis and muscular dystrophy
Antioxidant, Protection of male sperm and its motility hence it requires for male fertility. Formation of thyroid hormone
Excess amount creates mottling of teeth and deformity in bones (Hunch back)
Maintains enamel and checks dental decay by formation of flourapatite. Antibacterial
Irregular growth of bone, cartilage, connective tissue, anaemia
Functioning of lipase enzyme, urea synthesis, needed for haemoglobin synthesis, releases insulin, lactation, bone formation.
Irregular excretion of nitrogenous waste
Co-factor in some enzyme, formation of ascorbic acid..
Wheat, Giam, Peanuts, Yeast, Beans
Beri-beri/ Polyneuritis/ Cardio vascular atrophy
loss of appetite, Eatigue, Muscle Atrophy, paralysis, Cardiomegaly
From coenzymes in carbohydrate metabolism and help in pentose metabolism, Co-enzyme of Carboxylase and TPP
Riboflavin vitamin-G or Yellow Enzyme
Yeast, liver Milk, Cheese, leafy Vegtables and Intestinal Bacteria
Cheilosis, Glossitis, Fdatitis
Eye Inflammation and lip sores
Part of coenzymes (FMN and EAD) in ETS, needed for oxidation of ER
Warburg and Christian
Pantothenic acid, Yeast Ector
Yeast Peas, liver, Max in Wheat Honey
Burning feet syndrome
Abnormal Adrenal functioning, Nerve degeneration
Part of coenzyme A in cell rjparatiaT, require for nerve formation, Formation of actyldriine, For normal adrenal gland
Meat Milk, Wheat, liver, Banana
Marasmus Nausea and Vomiting
Skin lesions, CNS disorders and cmvoulsions
Part of coenzyme pyridoxal phosphate required in formation of amino acids and glycogen synthesis
Cyano - Cabalamine
liver and Eggs
Large and immature RBC
Coenzymes for nucleic acid synthesis nucleated RBC without hemoglobin
Citrus Fruits, Tomatoes and Peppers
Scurvy, Anaemia, Joint pain
Bleeding Gums,Loose Teeth, Aneamia and EferinfLll Swollen joints
Play an important role in collagen formation, functioning of Adrenal gland, Anti - odcant, EtythKgoiffiis, Absorption of Ca+2 and Fe+2
King (isolate from citrus juice)
Fish liver oil, Egg Yolk, Milk and liver
Rickets in Children and Ostomalacia in Adults
Weak and Soft bones distorted Skeleton and Poor muscular development
Facilitates Ca and P absorption by intestine
Steenbock and Fiess
Tocopherol/ Antisterlity/ Eeauty Vitamin
leafy Vegatables, Cereals and Vegatable fils
Macrocytic Anaemia, Muscular dystrophy
Destruction of REC
Antioxidant and plays an important role in ETS, Selenium metabolism, formation of RNA, DNA and REC
EVans and Sore
Yellow and Green Vegatables, Fruits, Milk and Eutter
Nightbliidness (Nyctalopia) Xeropthalmia Dermatitis
FferatiIisatic:n of skin, respiratory and urdna^nital tract
Growth Prevent keratini/ation of epithelial
Mc Collum and Faivis
leafy Vegatables, Soyabean oil
Severe bleeding and Intestinial Bacteria
Slow or delayed blood dotting
Synthesis of prothrombin for normal
Dam and Droisy bleed dotting, Present in intestinal bacteria
Biotin/ Vitamin-B7/ Antiavicin
Vegatables and Fresh Fruits, liver; Milk, Eggs
Scaly skin Muscle pain and weakness
Coenzyme in fatty acid synthesis and change of pyruvate into OAA
Liver, Green Vegetables, Banana and Oranges
Impairment of antibody synthesis and stunted growth Ulceration in mouth
Part of coenzymes in nucleic acid (Purine and pyramidine) synthesis and protein synthsis, EIyfhrepeifiis, Cell division in bone marrow
Niacin/ Vitamin 4-D/ PP- Eactor
Yeast Gram, Peanuts and Meat
Pellagera, Diarrhoea, Dermatitis, Dementia, Death (4-D Syndrome)
Scaly skin, Dehydration, Loss of Memory
Part of coenzymes NAD and NADP that acts as hydrogen acceptors and donors for functioirg of gastro - intstaial tract, and nervous system
The study of vitamins is called as vitaminology.
Vitamins were discovered by "Lunin".
The term "Vitamin" was given by "Funk" and "Hopkins" (B1 from unpolished rice–1912)
Vitamins are micronutrients, biological regulators and metabolic regulators (Vitamin theory)
Vitamins are imporant to maintain health, but cannot synthesize in the body.
Earliest known vitamin = vitamin 'C' (James Lind – scottish naval surgeon – 1747)
Earliest extracted vitamin = Vitamin - B1
Vitamins are following types –
(1) Fat soluble vitamin
(2) Water soluble vitamin
FAT - SOLUBLE VITAMIN
Vitamin-'A' (Retinol) –
Isomer of vitamin 'A' are –
(i) A1 – Retinol for vision.
(ii)A2 – Dehydro retinol which is essential for epithelial lining, glands and tear production.
Deficiency diseases –
(1) Night blindness – Due to deficiency of A1 It is also known as Nyctolopia (Inability to see in dark)
(2) Xeropthalmia – due to deficiency of A2 Tear formation is absent.
In this disease conjunctiva & cornea become dry due to keratinization of conjunctiva & cornea.
It is the main problem of blindness in children throughout the world.
Source – Good source is carrot, other sources are Guava, papaya, mango, spinach etc.
(3) Vitamin - "D" (Calciferol) It is also known as "Sunshine vitamin" or "Anti Ricket" vitamin.
Synthesized in skin from cholesterol by UV light.
It is necessary for bone & teeth Deficiency disease – Rickets in children and osteomalacia in adult.
Source– Good source cod liver oil and shark liver oil for both 'A' & 'D', Other sources are meat, liver, egg, milk etc.
Vitamin 'E' (Tocopherol) –
It is also known as "antisterility" vitamin or "beauty" vitamin.
This vitamin removes scar & wrinkles from skin.
Deficiency disease– Sterility.
Source – Egg, meat, cotton, seed oil Vitamin 'K' (Naphthoquinone)
It is also known as "antihaemorrhagic" vitamin.
Essential for synthesise of prothrombin.
Menadiane is the important source of the synthetic vitamin K.
Deficiency disease– Bleeding or delayed blood clotting.
Source– Carrot, tomato, liver, cabbage etc.
WATER – SOLUBLE VITAMIN
Vitamin B1 (Thiamine) –
It is also known as "anti beri-beri" factor or antineuritic factor.
Beri-Beri affects peripheral nervous system, alimentary canal & cardiovascular system.
Defi. disease– Beri-Beri, Wernicke's encepholopathy.
Source – Rice, wheat, egg and fish etc.
Vitamin B2 (Riboflavin)
It is also known as vitamin 'G' or lactoflavin or yellow enzyme.
It is essential for formation of FMN & FAD Defi. Disease– Cheliosis (Cracked lips at the corner of mouth) sore mouth and ulceration, digestive disorder, Pellegra like, beri-beri like.
Source– Cow's milk, egg, liver, yeast etc.
Vitamin B3 (Pantothenic acid) – greek word panthothen = everywhere
It is also known as yeast factor or chick antidermatitis factor.
It is help in formation of acetylcholine and Co enzyme A.
Defi. disease– Burning feet syndrome, fatigue & paralysis of muscles.
Source– Kidney, liver, yeast, milk, egg, meat etc.
Vitamin B5(Niacin or Nicotinic acid) – It is also known as "antipellagra" factor or vitamin PP (Pellagra preventing factor) It forms essential component of NAD & NADP Defi. disease– Pellagra in human beings (diarrhoea, dermatitis, dementia) and black tongue (hyper pigmentation) disease in dogs.
Source– Kidney, liver, milk, yeast, egg etc.
Vitamin B6 (Pyridoxine) Function as co-enzyme. It is also known as rat antidermatitis factor.
Defi. disease – Dermatitis, Anaemia, nervousness.
Source– Liver, meat, yeast, egg etc.
Vita B7 (Biotin) It is also known as vitamin 'H' or antiegg white injury factor (egg white contain avidin protein which is antagonist to vit. B7 – dermatitis, hair loss, nervous symptom).
It is essential for fat synthesis Defi.disease – Dermatitis Source – Vegetables, yeast, wheat egg etc.
Vitamin B12(Cyanocobalamine) – Extrinsic factor of castle It is also known as "antipernicious anaemic" factor or "RBC maturing" factor It promotes DNA synthesis & Maturation of RBCs.
Defi. disease – Pernicious anaemia.
Source– meat, liver etc.
Folic Acid – It is also known as folacin or Vitamin M.
It is needed for formation of RBC & synthesis of DNA Deficiency disease – Anaemia.
Source– green foilage of plant – cabbage, cauliflower Vitamin 'C' (Ascorbic Acid) It is also known as"anti-scurvy" or anti-viral, anti-cancer vitamin.
It is necessary for healing of the wound Deficiency disease– Scurvy (deficient formation of collagen fibres).
Source – Amla, Tomato, orange, Guava, Lemon (citrus fruit).
1. Citrin is also known as vitamin 'P' and controls vascular permeability.
2. Vitamin B17 – It is recently discovered anticancer vitamin.
3. Vitamin Q – helps in blood clotting.
4. Vita B15 – It is also known as pogonic acid, deficiency causes disorder in liver.
5. Vitamin B6 also used in the treatment of tuberculosis.
6. Thecodont teeth are also found in crocodile.
7. One pair of vomerine teeth is found in the palate of frog.
8. Fangs are the poison teeth of snakes, these are the maxillary teeth.
9. Upper incisor teeth are modified in tusk in elephant.
10. Upper canine teeth are modified in tusk in walrus.
11. Homodont type dentition are found in toothed whale.
12. Enamel is absent in Sloth and Armadillo.
13. Salivary glands are absent in whale.
14. The tongue is non-motile in whale.
15. Gall bladder is absent in lemprey, whale, rat and horse.
16. The main pancreatic duct is also known as duct of wirsung while accessory pancreatic duct is known as duct of santorini.
17. Antinueritic Vitamins - A, E and C.
18. Nature's most potent antioxidant - vitamin E, which is maximum in liver.
19. Vitamin B12 is absent in plants, However it is considered that Spirulina (an alga) contains B12.
20. Anticancer vitamins-A, B17, C etc.
Comparative Study of digestive system of Rabbit & Human
1.It is herbivorous animal, depends cellulose based food.
It is omnivorous, and depends on vegetarian and non-vegetarian food.
2.A small cleft is present in mid part of upper lip.
Cleft is absent.
3. Canine teeth are absent.
Canine teeth are present.
4. Dental formula :
Dental formula :
5. Infraorbital, Parotid, Sublingual and Submaxillary glands are present.
Parotid, Sublingual, Submaxillary glands are present but infraorbital is absent.
6 Caecum and Vermiform appendix are present where digestion of cellulose takes place.
Caecum & Vermiform appendix are vestigeal.
7. Rectum is beaded.
Rectum is non-beaded.
8. Eaeces are ejected outside in form of pelletes.
Eaeces are ejected out side in form of semi solid stod.
9. Coprophagy nature is present.
Coprophagy nature is absent