Digestion and Absorption

Question 1

When chyme leaves the stomach, where does it go first?

a. The Jejunum
b. The Esophagus
c. The duodenum
d. The Ilium

Answer 1

c. The duodenum

Question 2

Glucose is absorbed from the small intestine into the blood by:

Select one:

a. Facilitated diffusion
b. Simple diffusion
c. Secondary active transport
d. Osmosis

Answer 2

a. Facilitated diffusion

Question 3

Polysaccharides are broken down in the
Select one:
a. Mouth, stomach, colon
b. Stomach, duodenum, micro-villi
c. Mouth, oesophagus, stomach, duodenum
d. Mouth, micro-villi, duodenum

Answer 3

d. Mouth, micro-villi, duodenum

Question 4

Monosaccarides and disaccharides are absorbed by
Select one:
a. Active transport only
b. Facilitated transport only
c. Facilitated transport and osmosis
d. Active transport and osmosis
e. Active transport and facilitated transport
f. Only osmosis

Answer 4

e. Active transport and facilitated transport

Question 5

Select the correct statement(s) about zymogens (select all that apply):
Select one or more:
a. Amylase, lipase, trysinogen
b. Trypsinogen, chymotrypsinogen and procarboxypeptidases
c. Pepsinogen, trypsinogen, lipsinogen
d. Converted to their active form in order to break
down food substances

Answer 5

c. Pepsinogen, trypsinogen, lipsinogen
d. Converted to their active form in order to break
down food substances

Question 6

How does exercise intensity effect gastric emptying?

Answer 6

• gastric emptying is not affected up to about 80% VO2 max
• Above this a reduction in delivery of fluid and nutrients to small intestine may occur
• this may be important in intermittent type activity where there is a low average VO2 max but lots of short intermittent bouts of high intensity

Question 7

Role of… Kinases

Answer 7

transfer phosphate group

Question 8

Role of… Isomerases

Answer 8

rearrange molecule/change structure

Question 9

Role of… Dehydrogenases

Answer 9

remove water

Question 10

Role of… Synthetases

Answer 10

synthesis/makes a larger molecule

Question 11

Role of… Mutases

Answer 11

rearrange molecule

Question 12

Role of… Decarboxylases

Answer 12

removes carboxyl group

Question 13

Role of… Phosphatase

Answer 13

removes phosphate group

Question 14

Role of… Phosphorylase

Answer 14

catalyze the addition of phosphate group to an acceptor

Question 15

Role of… Deaminase

Answer 15

removes amine group

Question 16

What are the three parts of the stomach

Answer 16

 Fundus
 Corpus (body) - gastric glands that release mucus, pepsinogen and HCL
 Antrum - secretes mucus, pepsinogen and gastrin

Question 17

What are the 6 stages related to digestion and absorption and explain them.

Answer 17

 Ingestion: taking food in
 Secretion: of water acids buffers and enzymes
 Motility: contraction and relaxation of the smooth muscle e.g. peristalsis
 Digestion: Larger molecules into smaller ones through mechanical and chemical digestion
 Absorption: The products of digestion enter the cells within the body, mainly from the small intestine
 Defecation: Indigestible substances, cells, digested materials not absorbed leave the body as feces

Question 18

The semi-liquid mass of partly digested food expelled by the stomach is called

Answer 18

Chyme

Question 19

What is the Type of lipoprotein that transports cholesterol back to liver from peripheral cells.

Answer 19

HDL

Question 20

What is the function of the mouth?

Answer 20

The mouth is the first part in the process of digestion. Salivary glands help food go down the oesophagus.

Question 21

What is the function of the oesophagus?

Answer 21

The oesophagus is a long tube that leads from the mouth to the stomach. The epiglottis opens and closes to allow food to enter into the stomach.

Question 22

What is the function of the stomach?

Answer 22

The stomach secretes gastric juices that are used to break down food and turn it into bolus to semiliquid mass, (chyme).
Once food is broken down it will start to move into the small intestine causing the pyloric sphincter to close the stomach from intestine.

Question 23

What is the function of the small intestine?

Answer 23

Once food has entered the small intestine it will first pass through the duodenum by digestive juices from bile duct in pancreas & gallbladder, then pass through the jejunum, and continue until it reaches the ileum.

Question 24

What is the function of the large intestine (colon)?

Answer 24

Once food has traveled the length of the small intestine it will enter the large intestine by Ilocecal valve that will close small intestine from large intestine. large intestine absorbs fluid and creates bile (solid) and passes it off to the rectum.

Question 25

What is the function of digestion?

Answer 25

To render all foods into basic units of carbohydrates, fats, and protein so that the body can absorb and build tissue from them.

Question 26

How are nutrients transported?

Answer 26

The bloodstream vascular, and the lymphatic system are used to carry nutrients to various parts of the body.

Question 27

How are lipids transported in the body?

Answer 27

VLDL (very-low-density lipoprotein): made primarily by liver cells to transport lipids; made of triglycerides
LDL (low-density lipoproteins): carry cholesterol & triglycerides from liver; made of cholesterol
High has greater risk of heart disease.
HDL (high-density lipoproteins): transport cholesterol back to liver from peripheral cells; made of protein. High has low risk.

Question 28

What is the function of the Pancreas when it comes to metabolism?

Answer 28

Contributes digestive juices to GI tract, Produce insulin & glucagon to regulate body’s use of glucose.
Insulin Promotes cells to take up glucose for use as fuel,
Prompts liver cells to store glucose as glycogen.

Question 29

What is the function of the kidneys when it comes to metabolism?

Answer 29

Filter waste products from the blood for excretion in urine.
Reabsorb needed nutrients, maintaining chemical balances.
Convert a precursor compound to active vitamin D

Question 30

How is iron absorbed from the gut?

Answer 30

Fe(III) is converted to Fe(II) by iron reductase, so that it can enter enterocytes.

Some is re-oxidised back to Fe(III) and stored in ferritin, a storage protein in enterocytes.

Then bound to transferrin which transports it in the blood.

Question 31

What are the three salivary glands

Answer 31

• Parotid
• Submandibular
• sublingual

Question 32

Which cells produce the primary salivary secretions? 
A) Bartoiln
B) Myelin
C) Kupfer
D) Acinar

Answer 32

D) Acinar

Question 33

Parietal cells in the stomach secrete -???-and HCL.

Answer 33

Intrinsic factor

Question 34

What is pepsinogen an example of

Answer 34

A zymogen

Question 35

Describe the cephalic phase of digestion

Answer 35

Prior to arrival of food in stomach, vision, smell, chewing, taste stimulate gastric secretion – Parasympathetic nervous system also stimulates release of gastrin

Question 36

Describe the gastric phase of digestion

Answer 36

Stretch and products of protein digestion stimulate gastric secretions via local vaso-vagal reflex – Gastrin also released by same stimuli – All stimulate motility, larger meals increase rate of emptying

Question 37

Describe the intestinal phase of digestion

Answer 37

Chyme entering duodenum decreases gastric secretion and motility,
Removal of food leads to a decrease in pH (pH<2 inhibits gastrin release).
Distension of duodenum leads to release of hormones (including cholecystokinin) which inhibits gastrin release – ]

Question 38

How is the small intestine motility controlled? (3 factors)

Answer 38

Intrinsic, enteric NS
Hormones e.g. gastrin + CCK
Extrinsic nerves e.g. parasympathetic

Question 39

How are water soluble vitamins absorbed?
Select one or more:
a. diffusion
b. osmosis
c. active transport
d. bulk flow

Answer 39

a. diffusion

c. active transport

Question 40

Where is bile stored

Answer 40

gall bladder