Food Digestion Flashcards
is a process by which large complex organic molecules of food are disintegrated into small absorbable forms. Large molecules of diet are converted to small molecules by hydrolysis.
Digestion
present in the membrane of enterocytes are responsible for the absorption of most of the products of digestion except lipid and some monosaccharides.
Transporters (carriers) present in the membrane of enterocytes
pull over the pipe to prevent choking
epiglottis
An adult may consume how many carbohydrates per day
150-300 gram
carbohydrates are mainly starch and small amounts of
glycogen, dextrin, and inulin
found in saliva initiates carbohydrates digestion, requires chloride ion and has optimum ph of
salivary amylase, pH 5.8-7.0
It catalyzes the hydrolysis of alpha-1, 4-glycosidic linkages in starch, glycogen and dextrin and converts them to maltose and oligosaccharides
salivary amylase
3 parts of small intestine
duodenum, jejunum and ileum
protein will breakdown to
amino acids
carbohydrates will breakdown to
simple sugars
fats will breakdown to
glycerol and fatty acids
6 essential nutrients our body needs daily
protein
fat
carbohydrates
vitamins
minerals
water
are due to excessive production of digestives fluids
peptic ulcer and duodenal ulcer
Due to the absence of enzymes in the gastric juice, no digestion of carbohydrates occurs in the
in the stomach
4 parts of colon
ascending colon
transverse colon
descending colon
sigmoid colon
In the duodenum, pancreatic amylase acts on partly digested food. It is an endoglycosidase
a-amylase or amylopsin
continue the process of breakdown from the stomach, here pancreatic amylase on partly digested food.
- first segment of the the small intestine
duodenum
Products of starch or other polysaccharides digestion and dietary disaccharides are hydrolyzed by the enzymes present in the secretion of intestinal mucosal cells
in the small intestine
an acid secretion produced by glands in the duodenum wall that consist (3 chemicals water, mucus protein, and carbonate)
- intestinal juice
succus entericus
1 mono saccharide + 1 mono saccharide
simple diffusion
3 or more mono sacchride combine or absorb
facilitated diffusion
lower segment of small intestine, responsible to absorbs the nutrients, then they will passed away the nutrients to blood venous system or blood stream
jejunum and ileum
1 monosaccharide + 1monosaccharide absorbs or combine.
ex. mannose + xylose
simple diffusion
3 or more monosaccharide combine or absorbs
ex. glucose + galactose + fructose
facilitated diffusion
unable to utilize lactose, due to the deficiency of intestinal lactase. Symptoms abdominal cramps, diarrhea and flatulence
Lactose Intolerance or Lactase Deficiency
It occurs in early childhood. It is an inherited deficiency of two disaccharides namely sucrase and isomaltase
Sucrase-isomaltase deficiency
It is characterized by excretion of large amounts of disaccharide in urine
Disacchariduria
Defective carbohydrate absorption
malabsorption
It is an inherited disease. Absorption of glucose and galactose is slow due to defective carrier in the affected persons
Monosaccharide malabsorption
energy storage
lipids
grams per day an adult can consume fats
50-150grams per day
Due to lack of favorable conditions like emulsification and PH, no digestion of lipid occurs in the
mouth
In humans, initiation of fat digestion occurs in
In the stomach
is the major site of lipid digestion due to the pancreatic lipase. It requires colipase and bile salts for its activity.
small intestine, to be specific jejunum
a thick semifluid mass of partially digested food and digestive secretions that is formed in the stomach and intestine during digestion
chyme
usually secreted by the pancreas and transferred to the duodenum to participate in the hydrolysis and digestion of fat, cholesterol esters, and fat-soluble vitamins
pancreatic lipase
It is due to abnormal connection between urinary tract and lymphatics of small intestine
-characterized by excretion of milky urine.
Chyluria or chylous fistula
In the affected persons milky pleural fluid accumulates in pleural space due to abnormal connection between pleural space of lungs and lymphatics of small intestine.
Chylothorax
Lipid digestion and absorption is impaired in intra or extra hepatic cholestasis due to nonavailability of adequate amounts of bile salts, phospholipids and cholesterol. In cholestatic patients, liquid crystal vesicles are formed instead of mixed micelles.
cholestasis
It occurs in cholestatic patients due to malabsorption of lipids. EFAD during cholestasis itself can impair efficient lipid absorption and transport because proper biliary secretion of phospholipid is necessary for formation of mixed micelles and chylomicrons.
Essential fatty acid deficiency (EFAD)
normal adult intake of protein is
70-100grams per day
due to lack of protein splitting enzymes, no digestion of protein takes place
in the mouth
site where the digestion of the denatured proteins is initiated by pepsin present in gastric juice
in the stomach
is an endo peptidase, hydrolyzes the peptide bonds present within protein or polypeptide chain
pepsin
due to the absorption of oligopeptide, These peptides are toxic and cause inflammation and atrophy of intestinal mucosa in susceptible people. As a result, absorption is impaired in the small intestine.
non-tropical sprue
It occurs in children due to absorption of oligopeptides derived from wheat gluten. Hence, it is same as that of non-tropical sprue of adults. Symptoms of these diseases disappear when gluten is excluded from diet.
celiac disease
It is a genetic disorder. It is due to defective aromatic and hydrophobic amino acid carrier in the intestine. As a result, these amino acids are not absorbed. They are excreted in urine due to defective carrier in the kidney
hartnup disease
is a process in which complex food material is broken down into simpler substances
digestion
where digestion of food in takes place, it is a long tube extending from the mouth to the anus
alimentary canal
two glands that help in digestion
liver and pancreas
