Animal Nutrition

Herbivore

eat plants

Carnivore

eat other animals

Omnivore

eat plants and animals

Nutrient

substance in food needed for growth, maintenance, repair

Macronutrients

3 major nutrients that make up bulk of ingested food (carb, protein, lipid)

Micronutrient

2 nutrients required but in smaller amounts (vitamins, minerals)

Carbohydrate role

used by cells to make ATP during respiration Ex

Excess glucose makes

glycogen or fat

Neurons die without

glucose

Lipids role

protection, insulation, fuel storage

Phospholipids

in myelin sheath and cell membranes

Cholesterol

stabilizes membrane

Prostaglandins

smooth muscle contraction, BP control, inflammation

Proteins role

make up building blocks/structural materials, functional molecules

Protein examples as building block

keratin, collagen, elastin, muscle

Protein examples as functional molecule

enzymes and hormones

Essential Amino Acid

essential nutrient, must get from food in preassembled form, ½ of total amino acids (10/20)

Insufficient amino acids

protein deficiency (malnutrition)

“Complete” proteins

meat, eggs, cheese (all essential AA)

Essential Fatty Acids

certain unsaturated fatty acids that must be in diet, make up lipids, wide range of application in body

Example of Essential Fatty Acid

linoleic and linolenic acid (oils)

Vitamins

organic compound that helps body use nutrients, most are coenzymes and must be ingested, 13 total

Vitamin made in skin, not ingested

D

Vitamin made by intestinal bacteria

B and K

Vitamin converted from Beta-carotene

A

Water soluble Vitamins

B and C

Fat-soluble

A, D, E, K

Essential nutrients

required by cells and must be obtained from diet

Antioxidants

neutralize free radicals, Vitamins C, E, A and mineral selenium

Minerals

simple inorganic nutrients, 7 required in moderate

Harden bones

calcium, phosphorus, magnesium

Thyroid hormone synthesis

iodine

Major electrolytes in blood

sodium and chlorine

Epidemiology

study of human health/disease

Undernourishment

diet with less chemical energy than needed

Malnourishment

long-term absence of 1+ essential nutrients from diet, deformities, disease, death

Ingestion

act of eating

Suspension feeders

eat food from water (sponge, whale)

Substrate feeders

live in or on food source (caterpillar)

Fluid feeders

suck nutrient rich fluid from host (mosquito)

Bulk feeders

eat large pieces of food (human)

Propulsion

movement of food in GI tract (swallowing and peristalsis)

Peristalsis

propulsion of food with rhythmic contraction and relaxation

Mechanical breakdown/digestion

chewing, food with saliva, food churning in stomach, segmentation

Segmentation

local constriction of intestine that mixes food with digestive juices

Chemical digestion

catabolic steps with enzymes breaking down complex food into chemical building blocks

Enzymatic hydrolysis

splitting molecules with addition of water

Absorption

passage of digested fragments from lumen of GI tract into blood or lymph

Defecation

elimination of indigestible substance via anus

Intracellular digestion

food is engulfed by endocytosis and digested in food vacuole

Extracellular digestion

breakdown of food particles outside the cells

Gastrovascular cavity

in simple body animals and does digestion and distribution

Complete Digestive Tract

complex animals with digestive tubs from mouth to anus (alimentary canal, GI tract)

Mammalian accessory glands

salivary glands, pancreas, liver, gallbladder

Sphincters

valves that regulate movement between compartments

First stage of digestion

mechanical in the oral cavity

Second stage of digestion

salivary glands and amylase

Salivary glands

deliver saliva and lubricate food

Amylase

enzyme, initiates breakdown of glucose and starch

Bolus

circle food shaped by tongue

Esophagus

takes food from mouth down to stomach, peristalsis

Stomach

stores food and secretes gastric juice

Gastric juice

made of HCL and pepsin, converts meal to acid chime

Parietal cell

secrete H+ and Cl- separate

Chief cells

secrete inactive pepsinogen

Mucin cells

secrete mucus

Pepsinogen

activated to pepsin when mixed with HCL

Intrinsic factor

secreted by parietal cell for absorption of vitamin B12 in small intestine

Oxygen binding to hemoglobin

iron

To mature red blood cells need

vitamin B12

Pancreas

solution is alkaline and neutralizes acidic chyme

Liver

produces bile

Bile

aids in digestion and absorption of fat, yellow-green alkaline solution with bile salts and bilirubin

Bile salts

cholesterol derivatives

Bilirubin

pigment formed from heme after breakdown of old RBCs

Small intestine

longest section of GI tract, major organ of digestion and absorption

3 parts of small intestine

Duodenum, Jejunum, Ileum

Duodenum

acid chyme mixes from stomach with digestive juices from pancreas, liver, gallbladder, small intestine

Villi and microvilli

absorb nutrients in the small intestine, line the walls

Hepatic portal vein

delivers nutrient rich blood to the liver and to the heart

Large intestine

cecum, appendix, colon, rectum

Cecum

first part of large intestine. aids in fermentation of plant material

Appendix

lymphoid tissue and bacterial storehouse recolonizing gut when necessary, immunity

Colon oder

Ascending, Transverse, Descending, Sigmoid

Rectum

feces pass through to anus

Colon function

recover vitamin, water, electrolytes

Bacterial flora

1000+ bacteria types

Bacterial flora functions

ferments ingestible carbs/mucin, synthesize B complex/vitamin K, suppress pathogenic bacteria

Ruminants

elaborate adaptation for herbivorous diet, 4 compartments instead of 1, cow

Longer cecum

herbivores to digest vegetation

Excess calories are stored as

glycogen in liver/muscles and fat in adipose tissue

Overnourishment

causes obesity, excessive intake of food stored as fat

Obesity causes

diabetes (type II), colon/breast cancer, heart attack, stroke

Leptin

create feeling of being full