2.07-2.08 remember the structures of the digestive system
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2.07-2.08 Remember the structures of the digestive system. DIGESTION. The process of changing complex solid foods into simpler soluble forms which can be absorbed by body cells. BOLUS – soft, pliable ball – created from chewing and addition of saliva – it slides down esophagus - PowerPoint PPT PresentationTRANSCRIPT
The process of changing complex solid foods into simpler soluble forms which can be absorbed by body cells.
BOLUS – soft, pliable ball – created from chewing and addition of saliva – it slides down esophagus
PERISTALSIS – wavelike motions, moves food along esophagus, stomach and intestines
DIGESTION
Structures of the digestive system
Digestive system Also known as:
Alimentary Canal Digestive Tract Gastrointestinal Tract
Upper GI Lower GI
Over 30’ in length from mouth to anus
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Primary structures Mouth Esophagus Stomach Small intestines Large intestines
Accessory structures Tongue Teeth Salivary glands Pancreas Liver Gall bladder
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Structures of the digestive system
Structures of the digestive system
Mouth (buccal cavity)
Tongue Teeth Salivary Glands Palate Uvula The physical
breakdown of food begins here first…digestion begins in the mouth
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Structures of the digestive system
Tongue Attached to floor of
mouth Made of skeletal
muscle attached to four bones
Taste buds on the surface Sweet Sour Bitter Salty
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Structures of the digestive system
Teeth Primary (deciduous)
20 “baby teeth” Secondary
(permanent) 32 “adult teeth”
Teeth and tongue aid in physical /
mechanical digestion of food7
Structures of the digestive system
Salivary glands Parotid gland
Largest salivary gland Ptyalin in saliva converts
starches to simple sugars causes the initial chemical breakdown.
Submandibular gland Sublingual gland
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Structures of the digestive system
Palate – separates the mouth from the nasal cavity
Hard Soft
Uvula Flap of skin
hanging in the
back of the throat
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Structures of the digestive system
Pharynx (throat) Nasopharynx Oropharynx Hypopharynx
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Structures of the digestive system
Esophagus
Muscular tube, 10” long
Connects the pharynx and stomach
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Structures of the digestive system
Stomach Upper left
quadrant of the of the abdominal cavity
Fundus Body Pylorus
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Cardiac sphincter - controls passage of food into stomach and keeps it from going back into the throat.
PYLORIC SPHINCTER – valve, regulates the entrance of food into duodenum
RUGAE – mucous coat lining of stomach in folds when the stomach is empty
Stomach has muscular coat that allows it to contract (peristalsis) and push food into the small intestine
2 – 4 hours for stomach to empty
Structures of the digestive system
Small intestines – main function is absorption of NUTRIENTS
Duodenum First segment 12’ long
Jejunum Second segment 8’ long
Ileum Third segment 10-12’ long
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Structures of the digestive system Large intestines
Approximately 2” in diameter
5’ long
Responsible for elimination of waste and absorption of water
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Functions of the digestive system
Teeth Define mastication. How is the tooth’s shape
related to its function?
Incisors
Cuspids
Bicuspids
Molars
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Accessory Organs of DigestionPANCREAS
Located behind stomach Exocrine function – secretes digestive
enzymes to break down food. Also has endocrine function. Feather shaped organ
Functions of the digestive system
LiverProduce and store glucose in the form of GLYCOGENDetoxify alcohol, drugs and other harmful substancesManufacture blood proteinsManufactures bileStore Vitamins A, D and B complex Connects to gall bladder and small intestine by
ducts
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Functions of the digestive system
GallbladderSmall muscular green sac that secretes and stores bile Located in the right upper quadrant of abdominal cavity.When fatty foods digested, bile released by gallbladder
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Functions of the digestive system
Large intestine CHYME – semi-liquid food and
gastric juices Approx 2” in diameter Also called the colon CECUM – lower right portion of large
intestine APPENDIX-blind sac attached to
cecum, having no known function RECTUM – last portion of large
intestine ANUS – external opening of the Lg.
intestine
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Disorders of the digestive system
Anorexia Decreased or poor
appetite
Symptom
Anorexia nervosa Eating disorder
characterized by refusal to eat
Psychiatric disorder
Bulimia nervosa (binge eating and purging) is a psychiatric disorder as well
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Opposite disorder =
obesity
Obesity is one of the common eating disorders in the United States.
A person is considered obese if their BMI (body mass index is above 30.
How to calculate BMI:
BMI =( lbs/inches² )
(weight in pounds * 703 )
————————————
height in inches²
BMI Weight Status
Below 18.5 Underweight
18.5 -24.9 Normal
25 - 29.9 Overweight
30 & Above Obese
Disorders of the digestive system
Caries Cavities
How often should you brush and floss?
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Disorders of the digestive system
Cholecystitis Inflammation of the gall bladder
Sx = pain that radiates to right shoulder…frequently after eating fatty foods
How is it treated? - cholecystectomy
Cholelithiasis – gall stones
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Disorders of the digestive system
Cleft palate Hard and/or soft
palate doesn’t close completely during fetal development
Problems swallowing Surgery needed to
repair
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Disorders of the digestive system
Cirrhosis
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Chronic, progressive disease of liverNormal tissue replaced by fibrous connective tissue.
75% caused by excessive alcohol consumption (also caused by Tylenol use)
Disorders of the digestive system
Constipation When defecation delayed,
feces become dry and hard
Rx – diet with cereals, fruits, vegetables, (roughage), drinking plenty of fluids, exercise, and avoiding tension
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Disorders of the digestive disorders
DiarrheaLoose, watery, frequent bowel movements when feces pass along colon too rapidly
Caused by infection, poor diet, nervousness, toxic substances or irritants in food
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Disorders of the digestive disorders
GastroenteritisInflammation of mucous membrane lining of stomach and intestineCommon cause = virusSxs – nausea, vomiting, diarrhea for 24-36 hoursComplication = dehydrationPrevention…good handwashing
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Disorders of the digestive system
Gastroesophageal reflux disease (GERD)
Reflux of gastric acid into the espohagus
Sx – burning sensation that often worsens with laying flat…gets better with sitting up or raising head of bed
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Disorders of the digestive system
Hepatitis Acute Chronic
Hepatitis A (contaminated food or water borne), B (blood borne), C (blood borne), D, E
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Disorders of the digestive system
Irritable bowel syndrome Cause unknownSx – abdmonial pain, bloating, diarrhea and constipation (alternating)Trt – lifestyle and diet changes, medication
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Disorders of the digestive system
Chron’s Diseaseand Ulcerative Colitis
• Autoimmune disorders
• Type of inflammatory bowel disease
• Sxs – abdominal pain, severe diarrhea, malnutrition
Disorders of the digestive system
Peptic ulcer - Sore or lesion that forms in the mucosal lining of the stomach
Gastric ulcers in the stomach and duodenal ulcers in the duodenum
Cause – H. pylori (bacteria) is primary cause
Lifestyle factors that contribute: cigarette smoking, alcohol, stress, certain drugs
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Relevance of nutrition to the digestive system
Vitamins Fat soluble
Vitamins A, D, E, K Water soluble
Vitamins C, B
Proteins aid in wound healing
Carbohydrates such as bread and pasta offer quick energy
Electrolytes Calcium Chloride Magnesium Phosphorus Potassium Sodium
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