Final: Iron (Fe)

Question 1

What are the primary functions of iron?

Answer 1

Component of heme (hemoglobin and myoglobin); electron transport chain

Question 2

What happens with iron deficiency?

Answer 2

hypochromic microcytic anemia

Question 3

What are diet sources of iron?

Answer 3

Carnivores = RBCs of prey
Herbivores = inorganic sources

Question 4

What is the major clinical symptom of iron deficiency in growing animals?

Answer 4

listless and poor feed intake

Question 5

How does ferritin protect an animal from excessive dietary iron?

Answer 5

Binds free iron when it is in surplus; iron is sequestered for the life of the cell

Question 6

What are symptoms of iron toxicity?

Answer 6

Diarrhea, reduced feed intake, wgt gain

Question 7

What substances does iron interfere with (absorption)?

Answer 7

copper and zinc

Question 8

Why is free iron in tissues so harmful?

Answer 8

It is a strong oxidizing agent, very reactive, may lead to oxidative stress.
It is also required by bacteria for their growth so excess could contribute to infection

Question 9

Why are plants a poor source of iron?

Answer 9

Plant tissue itself is not very high in iron and iron is usually bound to phytate when present

Question 10

Why do animals that stay on milk diets tend to become anemic?

Answer 10

Milk is notoriously poor in iron; animal is growing fast and needs to make new RBC and iron enzymes

Question 11

How efficiently is iron absorbed?

Answer 11

Very efficiently across the intestine (has specific heme absorption mechanisms)

Question 12

What are inorganic sources of iron?

Answer 12

Ferric oxide (poor availability)
Ferrous sulfate (highly soluble, more available)

Question 13

What does ascorbic acid do in relation to iron?

Answer 13

Enhances absorption in man and monogastrics

Question 14

Where is iron stored when it is not immediately needed?

Answer 14

liver

Question 15

What is hepcidin?

Answer 15

Hormone made in liver when liver iron levels are adequate

Question 16

More than ___% of heme iron is absorbed across the apical membrane.

Answer 16

90%

Question 17

Only ___% of non-heme iron is absorbed across apical membrane of epithelial cells.

Answer 17

10-15%

Question 18

What is iron deficiency like in adult animals?

Answer 18

Rare; nearly all diets supply adequate Fe for adult animals!

Question 19

What is the usual exception to adult animals that causes iron deficiency?

Answer 19

hemorrhaging

Question 20

What type of iron do carnivores ingest?

Answer 20

heme iron

Question 21

What type of iron do herbivores ingest?

Answer 21

non-heme iron

Question 22

What do young animals rely on for iron until weaning?

Answer 22

liver stores of iron developed in utero

Question 23

What is unique about piglets and iron?

Answer 23

They are born with almost no iron stores, so are anemic, esp those raised in confinement (pasture = mud ingestion generally meets needs)

Question 24

What are signs of anemia in piglets?

Answer 24

Slow growth, rough hair coats, pale MM

Question 25

What does the body produce to guard against free iron in the body?

Answer 25

transferrin and lactoferrin - bind free iron making it unavailable for lipid peroxidation or bacterial growth

Question 26

What is hemochromatosis and what animals get it?

Answer 26

Buildup of iron in the liver; seen in pet mynahs, toucans, black rhinos

Question 27

What is the tx for hemochromatosis?

Answer 27

Blood-letting to remove iron from the body