Transcript Animal Nutrition

Animal Nutrition
nutrition
 Food taken in, taken apart and taken up
 Herbivores – plants/algae
 Carnivores – eat other animals
 Omnivores – consume animals and plants/algae
 Most animals are opportunistic – they will eat anything
outside their diets when normal foods are not available.
Adequate diet
 Must satisfy 3 nutritional needs
 Chemical energy for chemical processes
 Organic building blocks for macromolecules
 Essential nutrients – preassembled organic molecules
and minerals
 Essential fatty acids
 Essential amino acids
 Vitamins
 minerals
Malnutrition – lacking 1 or more of the essential nutrients
Food processing – 3 steps
 1. ingestion – act of eating or feeding
 2. digestion – food broken down into molecules small
enough for the body to absorb.
 3. absorption – take up of small molecules such as
amino acids and simple sugars
 Elimination – undigested material passes out of the
digestive system
Digestion
 Digestive enzymes (amylase) begin digestion in mouth.
 Intracellular digestion – food vacuoles, paramecium
 Extracellular digestion –
 Gastrovascular cavity – hydra
 Complete digestive tract – alimentary canal, mouth and
anus
Figure 33.8
Tongue
Oral cavity
Salivary
glands
Mouth
Pharynx
Esophagus
Salivary
glands
Esophagus
Liver
Gallbladder
Stomach
Sphincter
Gallbladder
Pancreas
Liver
Sphincter
Pancreas
Stomach
Small
intestine
Large
intestine
Rectum
Anus
Small
intestine
Large
intestine
Rectum
Anus
Duodenum of
small intestine
Accessory glands of digestive
system
 Mouth – salivary glands (accessory)
 Pancreas – endocrine gland
 Liver – filters blood, produces bile
 Gall bladder – stores bile, releases to S. Intestine
Peristalsis – waves of contraction/relaxation to move
food throughout alimentary canal.
Sphincters – muscular rings that regulate passage to
organs.
Oral cavity, pharynx and
esophagus
 Oral cavity – mouth, digestion begins
 Tongue – helps shapes digested food into a ball – bolus
 Pharynx – splits into 2 passages
 Trachea – respiratory
 Esophagus – leads to stomach
stomach
 Stores food, begins digestion
 Secretes components of a digestive fluid – gastric acid
 HCL – makes pH around 2, denatures proteins
 Pepsin – protein-digesting enzyme
 Gastric acid does not affect cells lining stomach because
of mucus released by cells
 Gastric ulcers – damaged areas of stomach lining
stomach
 Digestion occurs by churning of food (peristalsis) about
every 20 seconds.
 Chyme – acidic nutrient rich broth made from food
 Stomach sphincters closed during digestion
 Acid reflex – chyme backflows into esophagus
“heartburn”
Digestion in Small Intestine
 Most digestion of macromolecules from food, higher pH
than stomach, trypsin enzymes
 Longest part of alimentary canal, 20 feet, 6 meters
 Duodenum, first 25 cm of small intestine, chyme mixes
with digestive juices from pancreas, liver and gall
bladder.
 Bile – product of liver, contains bile salts
Absorption in the small
intestines
 Most absorption occurs across folded surface
 Villi, microvilli
 Surface area is roughly the size of a tennis court!
 Increase rate of absorption
Absorption of large intestines
 Includes the:
 Colon – ascending, transverse, descending, recovers water
 Cecum – pouch that ferments ingested material
 Appendix – finger like extension of the human cecum, contains
bacteria to break down material, accessory
 Rectum – terminal portion, store feces until eliminated. Has two
sphincters to regulate defecation
 Irritation of lining of colon – diarrhea
Dental/mutualistic adaptations
 Assortment of teach reflect the diet of the animal.
 Mutualistic bacteria and protists live in some digestive
organs of certain animals to help with digestion.
 Koala – to break down eukalyptus
 Ruminant digestion – 4 chambered stomach
 Rabbits/rodents – bacteria in L.I
 Termites – protists to help break down cellulose
Regulation of digestion
 Nervous system involved by triggering of substances
to be released (saliva, gastric juices)
 Endocrine system – controls digestion with release of
hormones released by stomach and duodenum.
 Energy storage -