AniNutrish Exam 2 Set 1

Prehension

Seizing and conveying food to the mouth

Mastication

Chewing and crushing food particles

Salivation

Secretion and mixing of saliva with food

Deglutition

Swallowing; movement of bolus from mouth to stomach

Defecation

Discharge of feces from the rectum or cloaca

Digestion

Breakdown of large molecules into smaller absorbable compounds

Absorption

Movement of nutrients from the GI tract into the bloodstream

Passive diffusion

Movement down a concentration gradient without energy

Facilitated diffusion

Movement down a concentration gradient using carrier proteins and no energy

Active transport

Movement against a concentration gradient requiring energy and carrier proteins

Phagocytosis

Cell engulfs large molecules; no digestion required

Mechanical digestion

Physical breakdown of food by chewing and churning

Chemical digestion

Digestion by chemicals such as hydrochloric acid and bile

Enzymatic digestion

Digestion by enzymes that hydrolyze nutrients

Parietal cells

Produce hydrochloric acid and intrinsic factor

Chief cells

Produce pepsinogen and gastric lipase

Neck cells

Produce mucus and replace damaged stomach cells

Pepsinogen

Inactive precursor of pepsin

Pepsin

Protein-digesting enzyme in the stomach

Rennin

Enzyme that acts on milk proteins

Mucin

Protective mucus coating of the stomach

Urease

Enzyme that breaks down urea and acts as a buffer

Bile

Produced by liver, stored in gallbladder, emulsifies fats

Trypsin

Pancreatic protease that digests proteins

Chymotrypsin

Pancreatic protease that digests proteins

Carboxypeptidase

Pancreatic enzyme that removes amino acids from proteins

Pancreatic lipase

Pancreatic enzyme that digests fats

Amylase

Enzyme that digests carbohydrates

Folds

Intestinal modification that increases absorptive surface area

Villi

Fingerlike projections that greatly increase absorptive surface area

Microvilli

Brush border projections that produce the greatest increase in absorptive surface area

Rumen

Primary site of microbial fermentation in ruminants

Abomasum

True stomach of ruminants

Proventriculus

Glandular stomach of birds

Cecum

Major site of fermentation in hindgut fermenters

Duodenum

Primary site of digestion in monogastrics

Jejunum

Major site of nutrient absorption

Ileum

Final portion of the small intestine before the large intestine

Pyloric sphincter

Controls movement of chyme from stomach to small intestine

Cardiac sphincter

Controls passage from esophagus into stomach