Chapter 34: Digestive System Flashcards
Alimentary canal
tubular digestive system with 2 openings: mouth and anus
Anus
exit point for waste material
Bile
produced by the liver; stored in gallbladder, bile salts important for breakdown of fats into smaller molecules of fats
Bolus
mass of food resulting from chewing action and wetting by saliva
Carnivore
Animal consuming meat/flesh
Cephalic phase
first neural phase of digestion, controlled by the neural response to the stimulus provided by food
Chyme
gastric juices mixed w food in the stomach
Digestion
mechanical and chemical breakdown of food into small organic fragments
Duodenum
first part of the small intestine, receives chyme from stomach
Endocrine system
system that releases hormones to control response of the glands in body, can excite or inhibit digestion
Esophagus
smooth muscle, tubular organ that connects the mouth to the stomach, peristalsis occurs here
Essential nutrient
nutrient that cannot be synthesized by the body; it must be obtained from food
Gallbladder
organ that stores and concentrates bile & sends to small intestine
Gastric phase
digestive phase beginning once food enters the stomach; gastric acids and enzymes process the ingested materials
Gastrovascular cavity
digestive system consisting of a single opening (in invertebrates)
Platylhelminthes: flatworms
Ctenophora: comb jellies
Cnidaria: coral, jellyfish
Gizzard
muscular organ that grinds food
Herbivore
Organism that eats plants only
Ileum
last part of the small intestine; connects the small intestine to the large intestine; absorption of bile salts & vitamins
Ingestion
1st part of system, act of taking in food
Intestinal phase
third digestive phase; begins when chyme enters duodenum, triggering digestive secretions from PLG and hormones control rate of gastric emptying
Jejunum
Second part of the small intestine, chemical digestion and nutrient absorption
Large intestine
reabsorbs water from undigested material and processes waste matter. Has 4 parts: cecum, colon, rectum and anal canal
Liver
produces bile, processes vitamins & fats, stores excess glucose as glycogen
Minerals
Calcium: bone formation
Magnesium: catalyst for ATP production
Sodium: nerve transmission, muscle contraction
Potassium: nerve transmission, water balance.
Iron: hemoglobin production
Monogastric
digestive system that consists of a single-chambered stomach
Omnivore
Organism that consumes both plants and animals
Pancreas
Endocrine and exocrine gland that secretes digestive juices, produces insulin
Peristalsis
wave-like movements of muscle tissue to push food
Proventriculus
Birds 2nd stomach, glandular part that secretes enzymes to help breakdown food
Rectum
area of the body where feces is stored until elimination
Roughage
Food high in fiber that is tough to digest
Ruminant
Four stomach animal
Ex. Goats
Salivary amylase
enzyme found in saliva, which converts carbohydrates to maltose
Secretin
hormone released by duodenum in response to acidity
Small intestine
Mostly absorption from food. 3 parts: duodenum, jejunum, ileum
Somatostatin
hormone released to stop acid secretion when the stomach is empty
Sphincter
band of muscle that controls movement of materials throughout the digestive tract
Stomach
saclike organ containing acidic digestive juices, major site of protein breakdown
Villi
folds on the inner surface of the small intestine, increase absorption area, make microvilli
Fat Soluble Vitamins
A: maintains healthy skin and eye health
D: helps body absorb calcium, maintains strong bones
E: antioxidant, boosts immune function
K: blood clotting
Water Soluble Vitamins
B: energy, influence growth
C: boosts immune function, fights skin aging and antioxidant
Obligate carnivores
rely on flesh for nutrients
Facultative carnivores
can eat non-animal food and animals, but mostly animals
Avian
2 chambered stomach
Proventriculus (enzymes) and gizzard (grinding)
All birds are avians
Crop
Stores food in birds, before proventriculus
Cloaca
Shared exit for urine and feces
Rumen and reticulum
2 of 4 stomachs in ruminants Contains prokaryotes and protists to digest cellulose fibers
Omasum
3rd stomach in ruminants, removes water from cud that is regurgitated
Abomasum
4th stomach in ruminants, cud is digested by enzymes produced here, similar to mono gastric stomach
Pseudo-ruminants
3 chambered stomach
Rumen, omasum, abomasum
Most digestion happens in cecum and spiral colon, NO reticulum
Pharynx
Passageway where food is swallowed
Tongue
Composed of striated muscle
Salivary glands
secrete saliva
sublingual, submandibular, parotid
Epiglottis
Covers opening into trachea and keeps food from air passageways
Pyloric sphincter
Junction between stomach and small intestine
Hepatic portal vein
Blood goes straight to here, takes nutrients to liver to detoxify, then send back to bloodstream
Cecum
Has small projection called the appendix, rabbits cecum is larger than humans bc it has to digest cellulose fibers
Colon
4 parts: ascending, transverse, descending and sigmoid colon
Leads to the rectum
Carb digestion
Starts in the mouth, enzymes in pancreas and small intestine help
HONEY
Lipid digestion
Begins in the stomach, mostly digestion in small intestine, bile acids help
BUTTER
Chylomicrons
Broken down version of lipids, transferred into lymph capillary then back into the body
Protein digestion
Mostly done in the stomach, proteins to peptides to amino acids that go to the small intestines
FISH OR BEANS
