GI and Renal Systems

Question 1

There is an _____ in lingual lipase and a ______ in salivary amylase during infancy

Answer 1

increase; decrease

Question 2

When do infants get teeth/gain chewing motion and ability

Answer 2

4-6 months

Question 3

What is the stomach capacity of an infant?

Answer 3

very small

Question 4

What types of feedings should the infant experience?

Answer 4

small, frequent; newborns will have 6-10 a day, 1 year will have 3-4

Question 5

How does the secretion of HCl and pepsin in infants compare to that in adults?

Answer 5

much less

Question 6

Does a decrease in secretion of HCl and pepsin impact protein digestion for human milk?

Answer 6

no

Question 7

What activity does gastric juice contain in an infant?

Answer 7

lipolytic activity (gastric lipase)

Question 8

What is lipolytic activity needed for?

Answer 8

digestion of medium chain triglycerides

Question 9

Where does most of the digestion in an infant take place?

Answer 9

small intestine (duodenum and upper jejunum)

Question 10

What three activities for protein digestion are low in young infants?

Answer 10

trypsin, chymotrypsin, and carboxypeptidases

Question 11

Human milk is relatively ___ in protein

Answer 11

low

Question 12

Why is getting too much protein not a problem in infants?

Answer 12

breast milk and formula are low in it but it could be a problem if it comes from other sources

Question 13

Absorbed intact during the first 4 months of life; needed for infant immune protection

Answer 13

immunoglobins

Question 14

Feeding solid foods proteins in infancy may contribute to what?

Answer 14

food allergies

Question 15

When does pancreatic lipase activity peak?

Answer 15

6-12 months

Question 16

Is bile salt secretion higher or lower in infants vs adults?

Answer 16

lower

Question 17

What does low bile salt secretion impair?

Answer 17

ability to form micelles

Question 18

What are micelles used for?

Answer 18

emulsification of bile

Question 19

Do MCT need micelle formation in order to digest and absorb fat?

Answer 19

no

Question 20

Long chain saturated fatty acids are _______ absorbed

Answer 20

poorly

Question 21

Human milk is better absorbed than ________ which is better absorbed than _______

Answer 21

vegetable oil/formula fat; cow’s milk fat

Question 22

How does the digestion of fat intake vary from that of an adult?

Answer 22

more difficulty digesting and absorbing a variety of different kinds of fats

Question 23

What can problems absorbing fat lead to?

Answer 23

steatorrhea

Question 24

What amylase activity is low in infants?

Answer 24

pancreatic alpha

Question 25

Why shouldn't infants be fed cereal from 0-4 months?

Answer 25

their capacity to hydrolyze starch is limited

Question 26

What are three mucosal disaccharidases

Answer 26

lactase, sucrase, maltase

Question 27

Are mucosal disacchardiase activities high at birth?

Answer 27

yes

Question 28

Vitamin and mineral absorption is ______

Answer 28

adequate

Question 29

Is mineral absorption decreased or increased in formula compared to breast milk?

Answer 29

decreased

Question 30

When do babies experience frequent, small amounts of yellow-green loose stool?

Answer 30

breast fed

Question 31

What four reflexes do infants have?

Answer 31

rooting, suckling, swallowing, extrusion

Question 32

What is the extrusion reflex?

Answer 32

food in front of mouth

Question 33

When do reflexes disappear?

Answer 33

3-4 months

Question 34

When should infants be placed on solid food?

Answer 34

not before 4-6 months

Question 35

When should infants be given cow's milk

Answer 35

not prior to the age of 1

Question 36

Why do infants have a problem with water balance and dehydration?

Answer 36

they have difficulty concentrating urine

Question 37

Nonmetabolizable dietary components, mostly electrolytes, in excess of body needs and nitrogen containing end products of metabolism

Answer 37

renal solutes

Question 38

What things may be secreted from the body?

Answer 38

renal solutes (Na, K, Cl, P, urea, uric acid, creatine)

Question 39

In what 3 situations is consideration of renal solute load important?

Answer 39

1. low fluid, high kcal diets 2. abnormally high extra renal water losses (fever, diarrhea) 3. impaired renal concentrating ability

Question 40

What is osmolarity

Answer 40

number of osmotically active particles per liter

Question 41

1 mole of glucose = ___ osmole of glucose

Answer 41

1

Question 42

1 mole of NaCl = ___ osmoses of NaCl solution

Answer 42

2

Question 43

Assumes that none of the elements were utilized by body or lost by non renal routes

Answer 43

Potential renal slute load

Question 44

How can PRSL be calculated?

Answer 44

assuming all dietary nitrogen is excreted as urea an adding electrolytes in food

Question 45

Crude protein =

Answer 45

N*6.25

Question 46

What type of milk is in the osmotic range for infants?

Answer 46

human; cows milk is not

Question 47

Immature and can maintain water and electrolyte balance only within a fairly narrow range of intakes and losses

Answer 47

Kidneys

Question 48

Not fully developed. tubules are short and do not reach mature proportions until 5 months

Answer 48

nephrons

Question 49

What is considered stressful for an infant's kidneys?

Answer 49

high protein, high mineral foods

Question 50

What is metabolic water derived from?

Answer 50

oxidation of fat, carbohydrate, and protein

Question 51

What are the main causes of water loss?

Answer 51

evaporation, fecal and urinary excretion

Question 52

What are usual evaporative losses of water?

Answer 52

450 mL for each 1000 kcal expended

Question 53

Infants cannot maintain water balance if predicted urine osmolarity is greater than ______

Answer 53

1100 mosmol/l

Question 54

What leads to dehydration?

Answer 54

infants having to use body water to get rid of renal solutes