Unit 7 Test: Digestive System Flashcards
What is the difference between the alimentary canal and an accessory organ?
Alimentary canal is where food actually passes through and digestion takes place.
Accessory organs aid digestion by producing and secreting enzymes, etc.
What is the structure of the mucous membrane in the alimentary canal?
Surface epithelium Smooth mm Connective tissue Glands Folds
What is the function of the mucous membrane in the alimentary canal?
Protects tissues beneath, secretion and absorption
What is the structure of the submucosa in the alimentary canal?
Glands
Vessels
Nerves
What is the function of the submucosa in the alimentary canal?
Carry away absorbed nutrients
What is the structure of the muscular layer in the alimentary canal?
Smooth mm
Nerves
What is the function of the muscular layer in the alimentary canal?
Produces movements of the tube
What is the structure of the serous layer in the alimentary canal?
Visceral peritoneum
What is the function of the serous layer in the alimentary canal?
Protests underlying tissues
Secrets serous fluid to lubricate outer surface
Describe the mixing movements of the alimentary canal.
Smooth mm in small segments contract rhythmically
Describe the propelling movements of the alimentary canal.
Wave like motion that moves contents down the canal. Ex: peristalsis
What are the functions of the mouth? The tongue?
Mechanical breakdown of food, begins chemical digestion of carbohydrates (amylase in saliva)!
What are the parts of the palate? What are their functions?
Hard palate: anterior portion, anchor for teeth
Soft palate: posterior portion raised during swallowing, contains palatine tonsils
How do the structure of teeth relate to their functions?
Incisors–> chisel shaped = biting
Cuspids—> cone shaped = tearing
Molars—> flat = grinding
What is the function salivary glands?
Moisten and bind food
Begins chemical digestion of food
Cleanses mouth and teeth
What is the function of the epiglottis?
It acts as a “switch” between the trachea and the esophagus to permit air to enter the trachea and food to enter the esophagus
Describe the structures and function of the esophagus.
Long, muscular tube with mucous glands
Peristalsis pushes food to the stomach
What are the functions of the stomach? Name the regions of the stomach and where they are located.
Secrets acid and enzymes. Mixes food with secretions to begin enzymatic breakdown of proteins. Cardiac Fundic Body Pyloric
What are the secretions of the mucous cell?
Mucous
What is the function and action of the mucous cell?
Slightly alkaline, prevents stomach breakdown
What is the secretion of the chief cell?
Pepsinogen
What is the function and action of the chief cell?
Turns into pepsin by HCl
Begins protein digestion
What are the secretions of the parietal cell?
HCl, intrinsic factor
What is the function and action of the parietal cell?
HCl breaks down food
Turns pepsinogen into pepsin
Intrinsic factor helps SI absorb vitamin B-12
What substances are absorbed from the stomach?
Some water
Certain salts
Alcohol
Some lipid soluble drugs
What factors affect the rate at which the stomach empties?
The pyloric sphincter releases as chyme accumulates in pyloric region. Rate of passage:
Fastest- liquids then carbs, then protein
Slowest- fat
Describe the action of amylase
Break down carbs into disaccharides
Describe the action of lipase
Fats–> fatty acids and glycerol
Describe the action of trypsin.
Proteins
Describe the action of chymotrypsin
Proteins
Describe the action of carboxypeptidase
Proteins
How are the actions of the pancreas controlled?!
They are stimulated by secretion of gastric juice from the stomach
Secretion and cholecystokinin=hormones released by duodenum—> stimulate secretion of pancreatic juice
Explain the digestive function of the liver.
Carbohydrate, protein, and lipid metabolism
Storage of glycogen, iron, vitamin A, D, B-12
Blood filtering and detoxification
Production of bile
What is the function of the gall bladder? What is the function of bile?
Stores and secrets bile into duodenum
Contains bile salts, bilirubin, cholesterol, electrolytes
Bile salts break up fat globules, enhance absorption of fatty acids, cholesterol and fat soluble vitamins
List the secretions of the small intestine and describe their functions.
Peptidase= amino acid breakdown Sucrase= sucrose breakdown Maltase= maltose breakdown Lactase= lactose breakdown Lipase= splits fats into fatty acids and cholesterol
What is a lacteal?
A lymphatic capillary found in each villi in the SI. It carries away wastes.
What is the function of the large intestine?
Absorb water
Complete the breakdown of some molecules (cellulose)
Produces feces
What is the function of mucous in the large intestine?
Protects the intestinal wall
Binds fecal matter together
What is the role of large intestinal bacteria?
To complete the breakdown of cellulose.
Describe the composition of feces.
Undigested food Water Electrolytes Mucous Shed intestinal cells Bacteria
Name the 6 categories of nutrients.
Proteins Vitamins Minerals Carbohydrates Lipids Water
Define digestion.
The mechanical and chemical breakdown of food, and the absorption of nutrients
What is the difference between a simple carbohydrate and a complex carbohydrate?
Simple: quick energy sources that do no supply any other nutrient or fiber
Complex: supply energy, but also supply other nutrients and fiber
Give some examples of simple and complex carbohydrates.
Simple: sugars (glucose, sucrose, fructose, maltose, lactose)
Complex: grains, seeds, beans, tubers
What is the main purpose of lipids?
To supply energy
Name the various functions of proteins in the human body.
Enzymes Plasma proteins Muscle components Some hormones Antibodies Energy
Broken down into amino acids
