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Here is the digestive system thought I would share :)
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Chapter 17
Digestion:Breaking down food into the smallest end products
End Products:Small particles, small enough to pass through cell membrane
Absorption:Getting products into the circulation for cells to use
Eliminate Waste: Bowel Movement
Alimentary Canal (Gastrointestinal Tract)
Open tube from the mouth to the anus,all lines with mucous membrane, in total about 30 ft long.
Accessory Organs
Add secretions to the canals.LiverGall BladderPancreas
Layers of the Digestive System
Mucosa
Submucosa
Muscular
Mucus membrane lining. Specialized
call to secrete mucus and
digestive enzymes
Connective tissue, blood & lymph tissue. Have parasympathetic & Sympathetic nerve ending•Parasympathetic~ increase digestive secretion•Sympathetic~ Decrease digestive secretions
(2) Layers of smooth muscle run in different directions when the contract causes a wave like motion to push food through digestive system called peristalsis
1.2.
3.
Layers of the Digestive System
Peritoneum: Sirius membrane lining of abdominal cavity and covers digestive organs allows for movement
A. Parietal: Lines entire cavity
B. Visceral: Internal layer cover over organs in the cavity
1.) Omentum: Towards front fold of membrane start at stomach to the intestine, like an apron covers & helps support.
2.) Mesentery: Covers and attaches to intestine and attaches to posterior abdominal wall supports and holds loops of bowl in place
4.
Mouth-Oral Cavity
Roof: Roof of the mouth or oral cavity is made of the HARD (anterior) and SOFT (posterior) Palates
Uvula: Hangs down from the soft palate is a V-shaped structure, which assist with swallowing
Tongue:Frenulum:Papillae:
Located on the floor of the mouth. The tongue has Three functions 1. Swallowing- Deglutition 2. Taste 3. Production of sound
Fold of mucous membrane under the tongue
Rough elevations on the tongue which contain the taste buds.
Teeth: Allows us to perform MASTICATION or chewing. Calcium is the most important mineral for tooth growth.
Definitions
Pulp Cavity:
Enamel:
Root:
Inner area of a tooth which contains nerves and blood supply
Covers the part of the tooth above the Gingiva (gum) is the hardest substance in the body.
Entire tooth under the gum line
Crown: Tooth above the gum line
Deciduous: Baby teeth we develop 20 starting at 6 month of and begin to shed at 6 years old. They are replaced by 32 permanent (adult) teeth.
1. Parotid:
2. Submandibular:
3. Sublingual:
Produce saliva which is made of and a digestive enzyme called Amylase.
Back of mandible in front of ear
Under mandible
Under the tongue, floor of mouth
The Pharnyx or throat transports food after deglutition or swallowing. The epiglottis closes off
the trachea during swallowing
Esophagus :10 inch long tube carrying food away from the
pharynx to the stomach. It is lined with mucous membrane and has a muscular wall which performs “peristalsis” (wave like motion to
propel food)
Stomach
•Collapsible pouch, muscular wall is capable of great distention.•Located in LUQ, below the diaphragm•Lined with mucous membrane that lays in the fold or Rugae when empty.
Fundus:
Body:
P ylorus :
Upper section
Central Portion
Lower narrow end
SphinctersCardiac/Lower
Esophageal Sphincter:
Pyloric Sphincter:
Between the esophagus and stomach.
Between the stomach and small intestines.
Chyme:When liquid food
mixture enters the small intestine
1.Reservoir: Stores food2.Secretion: Mucus, HCL, Pepsin(and enzyme that digests
protein) and intrinsic factor for absorption of Vit B12 for RBC production.
3. Churns Food- Breaks down food into smaller pieces
4. Absorption- small amounts of water, alcohol(much faster absorption) and some
medications.
• 20 foot long tube with a diameter of 1inch. Coiled loops fill most
abdominal cavity.1st Section about one
foot long, joins the stomach and is called
the duodenum. The next section is the jejunum, about 8 ft long. Finals section, the ileum, is
11ft long. All lined with mucous membrane
Villi
Small projections or villi extends into the lumen. Single cell thick wall. !st function of small intestine- absorption of nutrients from the food we eat. Some end products of digestion pass into the
capillaries where they join the venous system. End products of fats are absorbed by lacteals and enter the lymph system for transport to the bloodstream. Glands in the mucous lining of the small
intestine secrete mucus and enzyme which help food digestion. (the 2nd function of small intestine) its smooth muscle wall performs peristalsis, pushing digested food to the next structure.
LARGE INTESTINE
AKA COLON• 5-6FT LONG
•2 ½ INCH DIAMETER
CECUM- 1ST SECTION 3 INCHES LONG. SMALL POUCH OFF THE BOTTOM OF THE CECUM IS THE APPENDIX. (NO DIGESTIVE FUNCTION BUT CONTAINS LYMPHATIC TISSUE AND PLAYS A SMALL ROLE IN THE BODY’S IMMUNE SYSTEM.) ILEOCECAL VALVE PREVENTS BACKFLOW FROM THE CECUM OF THE
LARGE INTESTINES INTO THE ILEUM OF THE SMALL INTESTINES. ASCENDING COLON: RUNS UPWARD ALONG THE RIGHT SIDE OF THE ABDOMEN TRANSVERSE COLON: RUNS ACROSS THE ABDOMEN
DESCENDING COLON: RUNS DOWN THE LEFT SIDE INTO THE PELVIS SIGMOID COLON: IS AN S-SHAPED PORTION OF THE COLON.
RECTUM: FINAL 6-8 INCH SECTION SERVES AS A TEMPORARY STORAGE AREA FOR UNDIGESTIBLE OR UNABSORBABLE FOOD .
ANUS: EXTERNAL OPENING IT IS COMPOSED OF THE ANAL SPHINCTER (INVOLUNTARY) AND AN EXTERNAL ANAL SPHINCTER (VOLUNTARY)
FUNCTIONS: NO DIGESTION •ABSORBTION OF WATER , SOME MINERALS AND SOME VITAMINS (VIT K IS PRODUCED BY NORMAL FLORA IN THE INTESTINES)
• SECRETION OF MUCUS• ELIMINATION OF WASTE (FECES)
Accessory Organs of Digestion
LiverGallbladder
Pancreas
Liver-HepatoLocation: RUQ
Function: •Produce bile(1 qt/day)•Stores glucose as glycogen and released prn•Stores fat-solube vitamins-A,D,E,K (Carried around on fat particles)•Makes plasma protein-albumin for water balance globulins for immunity (antibodies) fibrinogen & prothrombin for clotting•Filters blood-filter out toxins•Hemolysis-break down of old blood cells
Bile contains: bile salts, bile rouben(break down of RBC) cholesterolFunction of bile: Emulsification fatsFlow: Out of liver through hepatic ducts and common bile duct. Backs up at sphincter and drains empties into gallbladder.
Gallbladder-CholecystLocation: RUQ under(behind) liver
Functions:1. Stores and concentrates bile after produced in liver
2. When chyme enters the small intestines, the gallbladder contracts to eject bile
through the cystic duct, into the common bile and then into the duodenum
Pancreas-most important organ for digestive enzyme
Location: LUQ posterior to stomach
Functions:1. Endocrine
Beta cells in the illets of langerhauns secrete insulin to decrease blood glucose. Alpha cells secrete
glucagon to increase blood glucose.2. Exocrine
Digestive secretions empty into the pancreatic duct then into the duodenum.
a. HCO3- alkaline substanceb. Enzymes – breakdown all three major nutrients
Digestive processBreaking down food into end products
1. Mechanical-physically breaking down moving fooda. chewing- mastication decrease size of food. Swallowing- deglutition- physically propel food
toward stomachb. Churning –turning in stomach mix food up with enzyme & HCLc. Peristalsis- wave like motion to churn food around in stomach
2. Chemical – changing chemical composition of the food. Breaking down large molecules into small molecules that make up end products.
d. Bile – emulsify fats• 3 nutrients that do not require chem digestion > vitamin, minerals, water, already in the
smallest form.b. Enzyme < need to break down other major nutrients carbs, proteins, fats > secreted in mouth,
stomach, small intestine, pancreas c. End products: smallest particles from major nutrients
CHO-carbohydrates>glucoseProteins>amino acids
Fats>fatty acids glycerol
Digestive processB. Absorption: most takes place in small intestine
1.)stomach- alcohol some medications2.)small intestine- absorption mostly takes place here
a. villi-Blood capillaries through circulation< carbs, proteinsb. Fats- lacteals- lymp- blood
3.) large intestines water is reabsorbed, absorbs vitamins and minerals
c. Elimination- eliminate feces1. Bulk – fiber indigestible substance a. cellulose-(seeds, shells, skins off fruits)
2. Also in fecesa. Bacteriab. Waterc. Mucus
d. Bile pigments – cause stool to have a dark color
THE END!