5 - Gastrointestinal Absorption PPT

Question 1

Welcome back dedicated GI studiers! Your first question- what is the total amount of fluid in liters that should be absorbed by the intestines each day?

Answer 1

8.5 Liters

Question 2

How do we get our 8.5L number?

Answer 2

Ingested fluid (1.5L) plus excreted fluid (7.0L)

Question 3

Why is the stomach poor at absorption?

Answer 3

It do be lackin’ in villi doe

Question 4

What makes the small intestine so highly absorptive?

Answer 4

It has many folds which increase the surface area

Question 5

Where are these circular folds best developed?

Answer 5

In the duodenum and jejunum

Question 6

What is the brush border?

Answer 6

Millions of villi that project from the surface of the mucosa

Question 7

What is pinocytosis?

Answer 7

Cellular drinking

Question 8

What contract rhythmically to keep the microvilli constantly moving?

Answer 8

Actin filaments

Question 9

What absorbs carbs, fats, AAs, ions and water each day?

Answer 9

The small intestine

Question 10

How is water absorbed and what laws must it obey?

Answer 10

Water is absorbed by diffusion and must obey the laws of osmosis.

Question 11

How is sodium absorbed?

Answer 11

Active transport

Question 12

Glucose is also absorbed by an active transport process. What mode is its absorption and what ion is involved?

Answer 12

• Co-transport mode
• Sodium takes it in

Question 13

(TRUE/FALSE): Glucose and galactose utilize the same transport process.

Answer 13

(TRUE): Almost completely identical.

Question 14

How does fructose differ from glucose and galactose as far as transportation?

Answer 14

Fructose is transported by facilitated diffusion

Question 15

Proteins break down into di/tripeptides and AAs, and are cotransported with what ion?

Answer 15

Sodium

Question 16

How do fats become soluble in chyme and thus able to penetrate the brush border to be absorbed?

Answer 16

They are taken in by bile micelles which are soluble in chyme

Question 17

How many milliliters of chyme normally passes through the ileocecal valve into the large intestine?

Answer 17

1500ml

Question 18

What can the rate of the chyme entering the large intestine indicate (slow vs fast)?

Answer 18

• Slow: not enough water, CONSTIPATION
• Fast: not enough liquid absorbed, DIARRHEA

Question 19

Why did the proximal half of the colon get the name “absorbing colon”? Think reeeally hard

Answer 19

Because most of the absorption in the large intestine occurs in the proximal half of the colon!!!

Question 20

What is the purpose of the distal colon?

Answer 20

It functions as FECES storage and is known as the storage colon

Question 21

(TRUE/FALSE): The mucosa in the large intestine can actively absorb sodium.

Answer 21

(TRUE): Sodium is actively absorbed.

Question 22

What hormone in large quantities enhances transport capability?

Answer 22

Aldosterone

Question 23

What does the mucosa of the large intestine secrete while it absorbs chloride ions?

Answer 23

Bicarbonate ions

Question 24

The combined absorption of sodium and chloride ions creates a __________ in the large intestine that causes __________ .

Answer 24

1. Gradient
2. Water absorption

Question 25

What are colonic bacteria capable of digesting?

Answer 25

Cellulose

Question 26

What is formed from the colonic bacteria’s digestion of cellulose?

Answer 26

Vitamins K, B1, B2, B12, and various gases

Question 27

Gimme the recipe for feces 😋

Answer 27

1/4 solid matter and 3/4 water. Preferred serve in a bowl 😉