Animal Nutrition

Front 1

Suspension feeder

Back 1

Sift small food particles from the water

Front 2

Substrate feeder

Back 2

Live in or on their food source

Front 3

Fluid feeder

Back 3

Suck nutrient-rich fluid from a living host

Front 4

Bulk feeder

Back 4

Eat large pieces of food

Front 5

Pepsinogen

Back 5

Inactive form of pepsin

Front 6

Pepsin

Back 6

Active form of pepsinogen. Makes up gastric juice when combined with hydrochloric acid. Breaks down proteins by splitting their peptide bonds.

Front 7

Chyme

Back 7

Combination of food and gastric juice. Acidic. Nutrient-rich.

Front 8

Chylomicron

Back 8

Small globules of fats mixed with cholesterol and coated with special proteins. This method of “packaging” allows these fats to first enter lacteals and eventually the blood stream.

Front 9

What are the four classes of essential nutrients?

Back 9

Essential Amino Acids-Amino acids that must be obtained in prefabricated form
Essential Fatty Acids-Fatty acids that an animal cannot make
Vitamins-Organic molecules with diverse functions, required in small amounts
Minerals-Inorganic nutrients such as calcium, zinc, and potassium

Front 10

Why do individuals who eat only plant proteins need to eat specific plant combinations?

Back 10

Plant proteins are “incomplete”, meaning not all of the necessary amino acids can be obtained from a single plant source.

Front 11

Contrast undernourishment with malnourishment.

Back 11

Undernourishment is the result of a lack of chemical energy for the body to carry out its necessary functions. Its effects are irreversible. Malnourishment is a long-term lack of one or more essential nutrients in the diet. Its effects can be reversed by changes in the diet.

Front 12

What are the main stages of food processing?

Back 12

Ingestion-The act of eating
Digestion-Process of breaking food down into molecules small enough to be absorbed
Absorption-Uptake of nutrients by body cells
Elimination-The passage of undigested material out of the digestive compartment

Front 13

Contrast intracellular and extracellular digestion.

Back 13

Intracellular digestion is where food particles are engulfed by endocytosis and digested within food vacuoles fused lysosomes. Food is digested within the cell. Extracellular digestion is where the breakdown of food particles is done outside of the cell. Food is digested in compartments that are continuous with the outside of the animal’s body.

Front 14

List the components of the mammalian digestive system and describe the function of each.

Back 14

Mouth: Where mechanical digestion takes place. Mucin, a slippery glycoprotein, lubricates food. Teeth chew food into smaller particles. The tongue screens food and helps shape the food into a bolus for swallowing.
Salivary glands: Deliver saliva to lubricate food. Amylase, found in saliva, initiates the breakdown of glucose polymers.
Esophagus: Conducts food from pharynx down to stomach by peristalsis.
Stomach: Stores food and secretes gastric juice to form acidic chyme.
Small intestine: Major organ of digestion and absorption.
Gall bladder: Stores and secretes bile.
Liver: Produces bile, regulates distribution of nutrients, and removes toxic substances.
Pancreas: Produces protein-digesting enzymes (proteases) trypsin and chymotrypsin.
Large intestine: Absorbs water.
Rectum: Stores feces until elimination.
Anus: Eliminates waste.

Front 15

What is the function of a sphincter and where are they found?

Back 15

Sphincters are valves that regulate the movement of materials between compartments. They can be found between the esophagus and stomach, the stomach and small intestine, and two between the rectum and anus.

Front 16

Be able to describe the digestive process that takes place in the stomach.

Back 16

Food undergoes both mechanical and chemical digestion in the stomach. The food undergoes mechanical digestion as stomach muscles contract and relax to churn the food. The food undergoes chemical digestions as gastric juice, a combination of hydrochloric acid and pepsin, convert the food to chyme.

Front 17

What are chief cells? parietal cells?

Back 17

Chief cells secrete the inactive form of pepsin, called pepsinogen. Parietal cells secrete separate hydrogen and chloride ions.

Front 18

What protects the stomach lining against self-digestion?

Back 18

Mucus protects the lining of the stomach and is replaced every three days.

Front 19

What is an ulcer and how is it caused?

Back 19

An ulcer is a damaged area of the stomach lining. They are caused by the bacterium Helicobacter pylon, which is resistant to the extreme acidity of the stomach.

Front 20

The duodenum is considered a major crossroad in digestion, why?

Back 20

The duodenum, the first part of the small intestine, is where chyme is mixed with enzymes secreted by the liver, gall bladder, pancreas, and the small intestine itself. It is where most of the digestion occurs in the small intestine.

Front 21

What are the major exocrine secretions of the pancreas and what are their roles in digestion?

Back 21

Trypsin and chymotrypsin are protein-digesting enzymes that are activated upon entering the duodenum.

Front 22

The surface area for a cylinder the size of the small intestine (six meters in length with a diameter of ~3.0 cm) is ~ 0.6 m2, yet the small intestine has an actual surface area of ~300 m2. How is this possible?

Back 22

The surface of the small intestine is covered by villi, which increase the surface area. The addition of microvilli on each of these villi further increases the surface area.

Front 23

What is the role of the lymphatic system in fat absorption?

Back 23

Inside each villus is a lacteal, a system consisting of a network of blood vessels and a small lymphatic vessel. This lacteal connects to the larger vessels of the lymphatic system. It absorbs fats from the small intestine and transports them to the blood stream.

Front 24

What are the components of the large intestine?

Back 24

Colon: Absorbs water
Cecum: Aids in fermentation of plant material
Rectum: Stores feces for elimination

Front 25

What is the major function of the colon?

Back 25

The major function of the colon is to recover about 90% of the water that has entered the alimentary canal.