Chapter 3 - Grastrointestinal Tract and Kidney

Question 1

An increase in ADH has what affect on the kidneys and on which structure?

Answer 1

It increases water absorption by the distal convoluted tubule.

Question 2

What happens to the breakdown products of fat in the small intestine?

Answer 2

They are resynthesized into fats and packaged into chylomicrons that are transported to the lymph and eventually the tissues.

Question 3

What contracts to prevent food regurgitation from the stomach?

Answer 3

gastroesophageal sphincter

Question 4

In the lower stomach, what is secreted by endocrine cells?

Answer 4

gastrin

Question 5

The thick ascending tube of the loop of Henle is mostly permeable to what molecule(s)?

Answer 5

Na⁺ and K⁺

Question 6

What is the purpose of the glycoprotein, intrinsic factor?

Answer 6

It complexes with Vitamin B12 to be absorbed by the small intestine.

Question 7

On average, how much urine is produced each day?

Answer 7

1-1.5 L

Question 8

Which enzyme breaks down proteins?

Answer 8

protease

Question 9

Which enzyme breaks down celluluse?

Answer 9

cellulase

Question 10

In the stomach, what is secreted by surface cells?

Answer 10

mucus

Question 11

What makes peristalsic action so quick?

Answer 11

the electrical continuity of gap junctions in the smooth muscle cells of the GI tract

Question 12

The loop of Henle and collecting duct are located in which portion of the kidney?

Answer 12

medulla

Question 13

What causes large intestinal reabsorption of water?

Answer 13

absorption of Na⁺ and Cl^-

Question 14

What is the functional unit of the kidney?

Answer 14

nephron

Question 15

What is the major pigment in bile?

Answer 15

bilirubin

Question 16

What do peptidases do?

Answer 16

They cleave peptide bonds, hydrolyzing proteins.

Question 17

Where is bile stored?

Answer 17

gallbladder

Question 18

What causes small intestinal reabsorption of water?

Answer 18

absorption of Na⁺ and glucose

Question 19

What two compounds secreted from the small intestine act in the pancreas?

Answer 19

1) cholecystekinin (CCK)
2) secretin

Question 20

What is the term for organisms that cannot change their internal ionic concentrations to meet that of their surrounding environment?

Answer 20

osmoregulators

Question 21

What is one of the most powerful stimulants of HCl release that often causes ulcers?

Answer 21

histamine

Question 22

What do the acini of the pancreas secrete to the small intestine?

Answer 22

bicarbonate

Question 23

In the stomach, what is secreted by parietal cells?

Answer 23

HCl and instrinsic factor

Question 24

The epithetial cells of the distal convoluted tubule are mostly permeable to what molecule(s)?

Answer 24

Na⁺

Question 25

90% of GI digestion occurs where?

Answer 25

small intestine

Question 26

The glomerulus and Bowman's capsule are located in which portion of the kidney?

Answer 26

cortex

Question 27

What compounds does the liver synthesize for digestion?

Answer 27

bile

Question 28

What is the term for organisms that can change their internal ionic concentrations to meet that of their surrounding environment?

Answer 28

osmoconformers

Question 29

The thin descending tube of the loop of Henle is mostly permeable to what molecule(s)?

Answer 29

H₂O

Question 30

What is the active form of pepsinogen and what class of enzyme is it? What stimulates its activation?

Answer 30

pepsin, a peptidase HCl stimulates its activation.

Question 31

What is the function of the glomerulus?

Answer 31

Filtration: It is a small capillary bed where blood from the heart is forced into the surrounding Bowman's capsule, filtering out large molecules from the plasma.

Question 32

In the stomach, what is the purpose of gastrin?

Answer 32

It stimulates the release of HCl and pepsinogen.

Question 33

About how many liters of filtrate pass through the kidneys each day?

Answer 33

180 L

Question 34

What are the three major nitrogenous waste products of metabolism?

Answer 34

1) ammonia 2) urea 3) uric acid

Question 35

How does bicarbonate react in the small intestine?

Answer 35

It combines with H⁺ to produce carbonic acid, which dissociates into CO₂ and H₂O.

Question 36

Where in the kidney does 65% of resbsorption and secretion occur?

Answer 36

proximal convoluted tubule

Question 37

The thin ascending tube of the loop of Henle is mostly permeable to which molecule(s)?

Answer 37

urea

Question 38

What structure transports urine from the kidneys to the bladder?

Answer 38

ureter

Question 39

Where is glucose totally reabsorbed in the kidney?

Answer 39

proximal convoluted tubule

Question 40

What is normal body pH?

Answer 40

7.4

Question 41

What is the typical osmolarity of plasma and filtrate?

Answer 41

~300 milliosmols/L

Question 42

In the stomach, what is secreted by chief cells?

Answer 42

pepsinogen

Question 43

What is the typical mechanism for reabsorptive transport in the proximal convoluted tubule?

Answer 43

It typically uses symport activity, transporting bigger molecules along with Na⁺.

Question 44

Which enzyme breaks down fats?

Answer 44

lipase

Question 45

What is the compensatory response to metabolic acidosis?

Answer 45

hyperventilation

Question 46

An increase in aldosterone has what effect on the kidneys and on which structure?

Answer 46

It increases Na⁺ absorption by the distal convoluted tubule.

Question 47

In the stomach, what is the purpose of mucus?

Answer 47

It protects the lining of the stomach and lubricates the food.

Question 48

What must be present in order for the small intestine to absorb glucose (this is a cotransporter)

Answer 48

Na⁺

Question 49

What is the purpose of CCK in relation to fats?

Answer 49

In the presence of fats, it acts to constrict the gallbladder and relax the sphincter of Oddi, allowing bile to empty into the small intestine and emulsify those fats.

Question 50

How many amino acids are essential?

Answer 50

9

Question 51

Why can only certain animals digest cellulose from plants?

Answer 51

Their digestive systems contain microorganisms that make and secrete the necessary enzyme to break it down.

Question 52

What macromolecules are digested starting in the mouth and by which enzyme?

Answer 52

starch and glycogen by salivary amylase

Question 53

Which enzyme breaks down starch and glycogen?

Answer 53

amylase