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31 Cards in this Set
- Front
- Back
alimentary canal
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a tube where digestion occurs
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saliva
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a liquid that contains digestive enzymes, mucus and other chemicals
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bolus
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chewed clump of food
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pharynx
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the upper portion of the throat – junction of the alimentary canal and the air passageway which air enters the lungs
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esophagus
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a long muscle encased tube which connects the pharynx to the stomach
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peristalsis
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muscle contractions
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stomach
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an elastic muscular sac capable of stretching to hold up to two liters of food
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Chyme
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thru the process of mechanical digestion the bolus is turned into an acidic liquid
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Small intestine
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a long narrow tube where digestion is completed and absorption of most nutrients takes place
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Liver
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the bodies largest internal organ – produces bile, stores glucose and glycogen and transforms ammonia to urea
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Gallbladder
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saclike structure that stores bile until it is secreted into the duodenum
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Pancreas
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produces and secretes pancreatic juice into the duodenum
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Villa
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small finger-like projections that line the small intestine
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Large intestine
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also known as the colon – wide and short tube from which water is absorbed into the body
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Feces
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undigested food material and other waste products
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Essential nutrients
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materials that must be ingested because your cells cannot construct them from other molecules
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Malnutrition
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diet lacking one or more essential nutrients
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Undernutrition
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a person whose diet is deficient in calories
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Obesity
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the condition of being seriously overweight with consequences to ones health
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Anorexia
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an extreme pursuit of thinness characteristic of self-starvation and weight loss
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Bulimia
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an eating disorder characterized by purging after bingeing
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six types of nutrients in food
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carbohydrates, fats, proteins, vitamins, minerals & water
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Digestion occurs on two steps:
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Step 1 – mechanical digestion – chewing
Step 2 – chemical digestion – breaking of bonds in large molecules to make smaller molecules |
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Six main organs make up the alimentary canal
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1. Mouth
2. Pharynx 3. Esophagus 4. Stomach 5. Small intestine 6. Large intestine |
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Small intestines
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major function is to absorb nutrients into the circulatory and lymphatic system-epithelial cells lining each villus have projections called microvilli each villus has small lymph vessels and a network of capillaries - when fatty acids and glycerol have been absorbed by the epithelial cells, they are recombined into fats and transported into the lymph vessel. Sugar and amino acids are absorbed into bloodstream through capillaries and villus
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Large Intestine (colon)
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– wide short tube –water is absorbed into the body here –contains bacteria that produces vitamin K and several B vitamins –job is to reabsorb water-saliva, gastric juice and other digestive juices contain large amounts of water –the large intestine finishes the job of digestion by absorbing the remaining water-re-absorption of water causes feces to be more solid-once again peristalsis is the mechanism that moves the material through the large intestine
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Pancreases
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produces and secretes pancreatic juice into the duodenum-pancreatic juice neutralizes the acid chime and also contains enzymes that hydrolyze carbohydrates, proteins and lipids
Pancreatic enzymes and enzymes secreted by the lining of the small intestine complete the chemical digestion of food |
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Bile
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contains no enzymes, but contains substances that help prepare fats such as those in butter, ice cream or nuts for digestion.
Bile separates small fat droplets preventing them from clumping into globs – this enables digestive enzymes to break the fats down more efficiently. |
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Stomach
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Gastric juice (mixture of hydrochloric acid, mucus and enzymes) is secreted by glands in the stomach lining – bathes the bolus after it enters the stomach lining
Hydrochloric acid breaks apart cells in food-kills bacteria swallowed with food Pepsin (one of the gastric enzymes) hydrolyzes large protein molecules into polypeptides Mechanical digestion turns the bolus into chyme (an acidic liquid) Stomach muscles contract and stir the chyme eventually forcing it into the small intestine Heartburn is caused when the passageway may open at inappropriate times allowing acidic chyme to flow backwards into the esophagus Pyloric sphincter – regulates the flow of chyme into the small intestine – it is located at the opposite end of the stomach – takes two to six hours for the stomach to empty |
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Esophagus
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In the esophagus food is moved by muscle contractions called peristalsis – not gravity.
A. Muscle at top of esophagus are striated (voluntary) B. Rest of the esophagus have smooth muscles (involuntary) C. When food reaches the pharynx – smooth muscles trigger swallowing reflex D. Smooth muscles contract moving food toward the stomach E. Food continues to move along the alimentary canal by peristalsis |
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Pharynx
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Tongue pushes food down the throat – when you swallow a cartilage flap called the epiglottis temporarily seals off the airway and prevents food from entering
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