Digestion Of Food Flashcards
two major functions of buccal cavity
mastication of food
facilitation of swallowing
_____ in saliva helps in lubricating and adhering the masticated food particles into a _______
mucus
bolus
bolus is conveyed into the ________ and then oesophagus by swallowing or __________
pharynx
deglutition
bolus passes down the oesophagus by successive waves of muscular contractions called
peristalsis
which sphincter controls the passage of food into the stomach
gastro-oesophageal
what does saliva contain
electrolytes (Na+, K+, Cl-, HCO3-)
enzymes (salivary amylase, lysozyme)
which is the carbohydrate splitting enzyme
salivary amylase
where does the chemical process of digestion begin
in oral cavity with the hydrolytic action of salivary amylase
about ______ percent of starch is hydrolysed in the oral cavity by salivary amylase with optimum pH ___ into a disaccharide _________
30
6.8
maltose
function of lysozyme
acts as an antibacterial agent that prevents infections
mucosa of stomach has _______ glands
gastric
three major types of cells of gastric glands
mucus neck cells
peptic/chief cells
parietal/oxyntic cells
what do mucus neck cells secrete
mucus
what do peptic or chief cells secrete
proenzyme pepsinogen
parietal or oxyntic cells secrete what
HCl and intrinsic factor (factor essential for absorption of vitamin B12)
how long does the stomach store food
4 to 5 hours
food after being churned in the stomach is called
chyme
which is the proteolytic enzyme of the stomach
pepsin
the proenzyme pepsinogen, on exposure to _______ gets coverted to active enzyme called _______
HCl
pepsin
pepsin converts proteins into _______ and ________
proteoses
peptones (peptides)
the _______ and ___________ in gastric juice play an important role in the lubrication and protection of the mucosal epithelium from excoriation by __________
mucus
bicarbonates
highly concentrated HCl
HCl provides the acidic pH of ______ which is optimal for pepsin
1.8
__________ is a proteolytic enzyme found in gastric juice of infants which helps in the digestion of milk proteins
rennin
which other enzyme is secreted for lipids in small amounts by gastric glands
lipases
which secretions are released into the small intestine
bile
pancreatic juice
intestinal juice
pancreatic juice and bile are released through which duct
hepato-pancreatic
which inactive enzymes does the pancreatic juice contain
trypsinogen
chymotrypsinogen
procarboxypeptidases
amylases
lipases
nucleases
trypsinogen is activated by which enzyme
enterokinase
enterokinase is secreted by
intestinal mucosa
active form of trypsinogen is called
trypsin
other enzymes in the pancreatic juice are activated by which enzyme
trypsin
what does bile contain
bile pigments (bilirubin and biliverdin)
bile salts
cholesterol
phospholipids
does bile contain enzymes
no
what does bile do
helps in emulsification of fats
activates lipases
during emulsification of fats, they are broken down into very small _______
micelles
intestinal mucosal epithelium has ______ cells which secrete mucus
goblet
intestinal juice is also called
succus entericus
which secretions constitute intestinal juice
secretions of brush border cells of mucosa
secretions of goblet cells
enzymes present in succus entericus
disaccharidases (eg. maltases)
dipeptidases
lipases
nucleosidases
________ along with _________ from the pancreatic juice protect the intestinal mucosa from acid as well as provide an alkaline medium of pH ___ for enzymatic activities
_________ also help in this
mucus
bicarbonates
7.8
sub-mucosal glands
sub-mucosal glands are called
brunner’s glands
proteins, peptones, proteoses are acted upon by which enzymes to form what
trypsin/chymotrypsin
carboxypeptidase
dipeptides
polysaccharides/carbohydrates/starch are hydrolysed by which enzyme to form what
pancreatic amylase
disaccharides
fats are broken down by _________ with the help of ____________ into ____________________ and ______________
lipases
bile
diglycerides
monoglycerides
_________ in the pancreatic juice acts on nucleic acids to form ___________ and _____
nucleases
nucleotides
nucleosides
dipeptides are broken down into which substances using which enzyme
amino acids
dipeptidases
maltose is broken down into which substances using which enzyme
glucose and glucose
maltase
lactose is broken down into which substances using which enzyme
glucose and galactose
lactase
sucrose is broken down into which substances using which enzyme
glucose and fructose
sucrase
nucleotides are converted to nucleosides using which enzyme
nucleosides are broken down into which substances using which enzyme
nucleotidases
sugars and bases
nucleosidases
diglycerides and monoglycerides and broken down into which substances using which enzyme
fatty acids and glycerol
lipases
breakdown of macromolecules occurs where
duodenum
after breakdown in duodenum, where are the simple substances absorbed
jejunum and ileum
functions of the large intestine
absorption of some water, minerals and certain drugs
secretion of mucus which helps in adhering the waste particles together and lubricating it for an easy passage
what are the undigested and unabsorbed substances called
faeces
faeces enters into caecum of large intestine through _____________, which prevents the back flow of matter
ileo-caecal valve
removal of faeces from body is known as
defaecation
