Flashcards in Ch. 13 Animal Physiology Deck (37):
Hydra - Digestion
Gastrovascular cavity, has only one opening.
Cells of the gastrodermis (lining of the gastrovascular cavity) secrete digestive enzymes into the cavity for
Earthworm - Digestion
From the mouth, food moves to the esophagus and then to the crop where it is stored. Posterior to the crop, the gizzard, which consists of thick, muscular walls, grinds up the food.
Earthworm - absorption
Is enhanced by the presence of a large fold in the upper surface of the intestine -> typhlosole. which greatly increases the surface area.
Grasshopper - Disgestion
a digestive tract consists of a long tube consisting of a crop and gizzard.
Humans - Digestion
Digestion - breaking down large food molecules into smaller usable molecules.
Absorption - the diffusion of these smaller molecules in the body's cells.
Get broken down into glycerol and fatty acids.
into amino acids
Vitamins and minerals
They are small enough to be absorbed without being digested.
made of smooth (involuntary) muscle.
Smooth (involuntary) muscle that pushes the food along the digestive tract by a process
Tongue and teeth break down food mechanically.
released by salivary glands begins the chemical breakdown of starch.
After swallowing. food is directed into the esophagus, by the epiglottis, a flap of cartilage in the back of the pharynx (throat). No digestion occurs in the esophagus.
Churns food mechanically and secretes gastic juice.
A mixture of the enzyme pepsinogen and hydrochloric acid that begins the digestion of proteins.
The acid environment (pH 2-3) activates ________ to become the active enzyme ______ and also kills germs.
Pepsinogen ... pepsin
The stomach of all mammals contains _______ to aid in the digestion of the protein in milk.
__________ at the top of the stomach keeps food in the stomach from backing up into the esophagus and burning it.
__________ at the bottom of the stomach keeps the food in the stomach long enough to be digested.
Digestion is completed in the _________
Intestinal enzymes and pancreatic amylases hydrolyze starch and glycogen into _______.
_______ is produced in the liver and stored in the gallbladder
Bile is released into the ______ as needed and acts as an _______ to break down fats, creating greater surface area for digestive enzymes.
Small intestine....... emulsifier
________ such as trypsin and chymotrypsin, continue to break down proteins.
Nucleic acids are hydrolyzed by ________
_______ break down fats
The lower part of the small intestine is the site of _______.
Millions of fingerlike projections called _____ absorb all the nutrients that were previously released from digested food.
Each villus contains _______, which absorb amino acids, vitamins and monosaccharides.
_______, a small vessel of the lymphatic system, which absorbs fatty acids and glycerol.
Each epithelial cell of the villus has many microscopic cytoplasmic appendages called ________
Microvilli that greatly increase the rate of nutrient absorption by the villi.
Gastrin - site of production and Effect
Stomach wall.... Stimulates sustained secretion of gastric juice.
Secretin- site of production and Effect
Duodenum wall ..... Stimulates pancreas to release bicarbonate to neutralize acid in duodenum.