GIT digestion Flashcards by Iseoluwa Ojo

Primary site for digestion and absorption of food is —-?

Small intestine

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Length of small intestine

About 6 meters

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Mucous membranes of SI are covered by ——

Intestinal villi

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Height and diameter of an intestinal villi

H:about 1mm
D: less than 1mm

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Villi is lined by ———- cells which are called ——- and give rise to ———

Columnar cells
Enterocytes
Microvilli

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Within each villus there is a central channel called ———which opens into ——— vessels

Lacteals

Lymphatic vessels

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Enterochromaffin cells are also called ——-

Argentaffin cells

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Function of Enterochromaffin cells

To secrete intrinsic factor

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Function of goblet cells

Secrete mucus

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Function of paneth cells

Secrete cytokinins called defensins

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Brunners glands are found on the —- part of the —-

First part

Duodenum

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Brunners glands secrete - and -

Mucous and enzymes

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The major types of carbs found in diet are??

Starches
Sucrose
Lactose

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Carbs digestion begins in the ——- by ——— enzyme

Mouth

Alpha amylase

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——- breaks ——— linkages of ———in the mouth to create smaller ———saccharides

Alpha amylase

1,4 linkages

Starch

Oligosaccharrides

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Alpha amylase is inactivated by —— in the ——-

Acidic ph

Stomach

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What digests carbs in the stomach?

Nothing

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——- continues the digestion of starch in the small intestine to produce more —- and ——-

Pancreatic amylase

Maltose
Isomaltose

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——- gotten from ——— breaks disaccharides into———

Brush border saccharridases

Brush border of small intestine

Monosaccharides

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—— breaks maltose into ——-
—— breaks isonaltose into ——-
——- breaks sucrose into ——-
——- breaks lactose into ——-

Maltase -glucose
IsoMaltase- glucose
Sucrase- glucose and fructose
Lactase- glucose and galactase

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Out of the common end products of carbs digestion in the gut, glucose accounts for —- %while fructose and galactose account for ——%

80%

20%

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List the carbs digestive enzymes contained in the enterocytes

Sucrase, lactase, maltase, alpha dextrinase

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Enterocytes absorb :
Glucose through - transport
Fructose through —- transport
Galactose through —- transport

SGLT-1
Facilitated diffusion
SGLT-1

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Full meaning of ORT

Oral rehydration therapy

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Situations where ORT is used

Rehydration | As a treatment of enteric disease like cholera

Principle of ORT

SGLT-1 takes in glucose and sodium while water and chloride follow

—— starts the digestion of proteins in the ——— at a ph of ——-

Pepsin Stomach 2-3

Pepsin digestive activity accounts for ——% of total protein digestion

10-20%

Pepsin break protein into _____

Proteases Peptones Polypeptides

Most protein digestion occurs in the ———

Upper small intestine

Peptidases are found in ——-

Microvilli of enterocytes

List the protein digestion enzymes present in the pancreatic juice , their substrate, and their products

Trypsin- proteoses and peptones- dipeptides , tripeptides, and polypeptides Chymotrypsin-proteoses and peptones- dipeptides , tripeptides, and polypeptides Carboxypeptidase A and B-dipeptides , tripeptides, and polypeptides-amino acids

List the protein digestion enzymes present in the succus entericus, their substrate, and their products

Dipeptidases- dipeptides- amino acids Tripeptidases- ttipeptides- amino acids Amino peptidases-large polypeptides-amino acids

Places where final digestion of protein occurs

Intestinal lumen Brush border of mucosal cells Cytoplasm of mucosal cells

Absorption of whole proteins is by ——

Endocytosis

Absorption of small peptides is by ——

Endocytosis

Dipeptides,tripeptides, and amino acids are absorbed from the intestinal lumen by———

Sodium dependent cotransport

Which is absorbed actively, and which is absorbed passively.: L-amino acids or D-amino acids

L: active D:passive

L-amino acids are absorbed by - transport. | D-amino acids are absorbed by - transport

Sodium co transport Facilitated diffusion

Relative rate of absorption of amino acids in the different sections of small intestine??

Rate of absorption is faster in the duodenum and JEJUNUM than ileum

Amino acid is catabolyzed to give ——- and ——?

Urea and co2

Body protein are broken down into amino acids by a process called —-?

Proteolysis

Dipeptides and tripeptides are broken down to amino acids in the ——-

Enterocytes

Amino acids from the cells enter the capillaries through ——

Facilitated diffusion

Digestion of fats begins in the ——- by ——- secreted in the ——-

Stomach Lingual lipase Mouth

Lingual lipase digests about —-% of the dietary fats

30%

Most fat digestion occurs in the —— due to the presence of ———-

Intestine Pancreatic lipase,bile salts, colipase

Colipase is activated in the ——- by ——

Lumen of small intestine Trypsin

Pancreatic lipase breaks TAG at the —- and —— bonds to give—- and —-

1- and 3- bonds Free fatty acids and 2-MAG

Micelles are formed by——- and have a size of about ——— composing of about ——- bile salts

Bile salt 3-6nm 20-40 molecules of bile salts

Bile salts are amphiteric . | T/F

What makes the micelles stable in water??

Their polar groups

Polar groups of micelles are ——vely charges

Negative

The bile salts help to —— the ——- across the ——

Transport MAG and FFA Brush borders of intestinal epithelial cells

For fats. | In the mucosal cells,most —- are converted into ——

MAG TAG

Triglycerides are also formed in the cells by ———- of fatty acids with more than—- carbon atoms

Re-esterification 10-12 carbon atoms

Fate of fatty acids with less that 10or 12carbon atoms

Enter the portal blood from mucosal cells and transported as free fatty acids or unesterified fatty acids

Most of the fats are absorbed in the ——part of the small intestine

Upper part

The new TAG leave the mucosal cells as —— and enter the ——- to flow then empty into the ——-

Cyclomicrons Thoracic lymph duct Circulating blood

Cyclomicrons leave the mucosal cells by ——

Exocytosis

How much chyme passes into the large intestine daily

1500ml

Most of water and electrolytes are absorbed in the——-

Large intestine

About less that —- of fluid is excreted through feaces

100ml

Most of the absorption in the large intestine occurs in which part of the colon —-?

Proximal colon

Proximal colon is also called—?

Absorbing colon

Distal colon is also called—-?

Storage colon

Ions that are secreted and ions that are reabsorbed in the colon

Na and Cl are reabsorbed Hco3- is secreted

Equal amount of - is secreted for equal amount chloride absorbed

Bicarbonate

Function of bicarbonate in the colon

To neutralize the acidic products of bacterial actions in the colon

About —-liters of fluid and electrolyte are absorbed by the colon every day

5-8 liters

Effect of cholera on crypts

Causes the to secrete about 10 or more liters of fluid every day leading to severe and sometimes lethal diarrhea

Most common bacteria of the colon is—?

Colon bacilli

Vitamins formed from bacterial activity in the the colon

K, B12, B1, B2

Gases produced i the colon by bacterias

Co2, H2, methane

Faces normally are -/4 water and -/4 solid matter

3 1

Solid matter of faces is composed of what???…and in what percentages???

``` 30% dead bacteria 30% undigested roughage from food and dried constituents of digestive juices 10-20% fat 10-20% inorganic matter 2-3% protein ```

Brown color of faces is caused by ——

Stercobilin and urobilin

Odor of fecaes is caused by ——?

Products of bacterial action

Product of Bacterial action vary from one person to another . T/F

Product of Bacterial action is dependent on —-?

Colonic bacterial flora and type of food eaten

Give 4 examples of the odoriferous products of bacterial action

Hydrogen sulphide Indole Skatole Mercaptans

Ca absorption is regulated by ——

Vitamin D and parathormone

Coeliac disease is an autoimmune disorder that results in —-?

Damage of the mucosa and atrophy of the villi leading to impaired digestion and absorption

Iron binds to —- in _____ And Iron binds to —— in ——

Apoferritin in intestinal cell | Transferrin in blood

Which section of the small intestine has the longest villi

Duodenum

Epithelial cells of the small intestine are retrieved hope often

Every 3-6 days

Trehalose is digested by —- into ——

Trehalase 2 glucose

What transporter transports glucose and galactose across the basolateral membrane

GLUT 2

Name of transporter of fructose. Across apical border Across basolateral border

GLUT-5 | GLUT -2

Lactose intolerance is caused by —-?

Lactase deficiency

Cholesterol ester is digested by ———-enzyme into —— and ——

Cholesterol ester hydrolase Cholesterol and fatty acid

Phospholipids are digested by———enzyme into —— and ——

Phospholipase A2 Lysolecithin and fatty acids

Which enzyme in fat digestion is secreted in its active form

Cholesterol ester hydrolase

Do micelles enter the cell? | Do bile salts enter the cell??

No | No

Average diameter of cyclomicrons are???

100nm

Cyclomicrons are made up of —— and /—-

Phospholipids 80% | Apoproteins 20%

Which apoprotein is essential to produce cyclomicrons

Apo-B

Which tight junctions permit movement by paracellular transport. Small intestine or colon

Small intestine

``` How are the following absorbed.: Fat soluble vitamins Water soluble vitamins Vitamins B12 Bile salt ```

Micelles Na-dependent co transport Intrinsic factor(in the ileum) Na-bile salt cotransport