BIO 202 Digestive System Part I Overview and Mouth to Stomach
|
|
- Abraham Phillips
- 8 years ago
- Views:
Transcription
1 1 BIO 202 Digestive System Part I Overview and Mouth to Stomach Function of the Digestive System Ingestion Taking food and water into the mouth Break down the food Mechanical digestion: chewing, mixing, and churning food Chemical digestion: digestive enzymes breakdown food Absorb nutrients Movement of nutrients from the GI tract to the blood or lymph Release of waste Elimination of indigestible solid wastes Organs Within the Digestive System Two groups of organs within the digestive system The digestive tract or gastrointestinal (GI) tract is a muscular tube that winds through the body and is responsible for the digestion and absorption of food Oral cavity, pharynx, esophagus, stomach, small intestine, large intestine, and anus The accessory digestive organs aid in the breakdown of foodstuffs Teeth, tongue, gallbladder, salivary glands, liver, and pancreas Tunics Three major functions: Secretion of mucus Absorption of end products of digestion Protection against infectious disease Mucus secretions: Protect digestive organs from digesting themselves Ease food along the tract Stomach and small intestine mucosa contain: Enzyme secreting cells Hormone secreting cells (making them endocrine and digestive organs)
2 Tunics Mucosa Innermost layer that lines the lumen of the alimentary canal Consists of a mucous epithelium, a lamina propria, and a muscularis mucosae Submucosa Connective tissue layer containing the submucosal plexus (part of the enteric plexus), blood vessels, and small glands Muscularis Consists of an inner layer of circular smooth muscle and an outer layer of longitudinal smooth muscle The myenteric plexus is between the two muscle layers Serosa or adventitia Forms the outermost layer of the digestive tract 2 Enteric Nervous System Consists of nerve plexuses within the wall of the digestive tract Serves the digestive tract and regulates digestive activity. Composed of two major intrinsic nerve plexuses: Submucosal nerve plexus: regulates glands and smooth muscle in the mucosa Myenteric nerve plexus: major nerve supply that controls GI tract mobility
3 3 Peritoneum The peritoneum is a serous membrane that lines the abdominopelvic cavity and organs Mesenteries are peritoneum that extend from the body wall to many of the abdominopelvic organs Retroperitoneal organs are located behind the peritoneum Oral Cavity Oral cavity or mouth Is bounded by lips, cheeks, palate, and tongue Has the oral orifice as its anterior opening Is continuous with the oropharynx posteriorly Divided into two regions Vestibule Space between the lips or cheeks and the alveolar processes, which contain the teeth Oral Cavity Proper Lies medial to the alveolar processes To withstand abrasions: The mouth is lined with stratified squamous epithelium Oral Cavity Lips and Cheeks Involved in facial expression, mastication, and speech Palate Forms the roof of the mouth. Consists of hard and soft areas Hard palate: assists the tongue in chewing Soft palate: mobile fold formed mostly of skeletal muscle. Projecting from the soft palate is the uvula Closes off the nasopharynx during swallowing The mouth contains accessory glands (salivary glands) and accessory organs (teeth and tongue) which begin the digestive process
4 4 Tongue Occupies the floor of the mouth and fills the oral cavity when mouth is closed Functions include: Gripping and repositioning food during chewing Mixing food with saliva and forming the bolus Initiation of swallowing, and speech Frenulum secures the tongue to the floor of the mouth Surface bears papillae Filiform whitish, give the tongue roughness and provide friction Fungiform reddish, scattered over the tongue Circumvallate (vallate) V shaped row in back of tongue These three house taste buds Foliate on the lateral aspects of the posterior tongue Teeth Tear and grind food Born with 20 deciduous teeth Erupt between about 6 months and 24 months of age Deciduous teeth are replaced by 32 permanent teeth Replacement starts at about 5 years and the process is complete by about 11 years The types of teeth are Incisors Canines Premolars Molars A tooth consists of a crown, a neck, and a root Crown Exposed part of the tooth above the gingiva Dentin covered by enamel Enamel: acellular material composed of calcium salts and hydroxyapatite crystals; the hardest substance in the body Root Portion of the tooth embedded in the jawbone Composed of dentin Within the dentin of the root is the pulp cavity, which is filled with pulp, blood vessels, and nerves Periodontal ligaments hold the teeth in the alveoli
5 5 Salivary Glands Produce and secrete saliva that: Cleanses the mouth Moistens and dissolves food chemicals Aids in bolus formation Contains enzymes that break down starch Salivary glands produce serous and mucous secretions The three pairs of large salivary glands are the parotid, submandibular, and sublingual Saliva Produce ~1 liter of saliva/day Secreted from serous and mucous cells of salivary glands Serous: enzymes, ions, and mucin Mucous: produce mucous % water and slightly acidic solution containing Electrolytes Digestive enzyme: salivary amylase Proteins: mucin, lysozyme, defensins, and IgA Metabolic wastes: urea and uric acid Control of Salivation Primarily by the parasympathetic division of the autonomic nervous system Salivary glands secrete serous, enzyme rich saliva in response to: Ingested food which stimulates chemoreceptors and pressoreceptors The thought of food Strong sympathetic stimulation inhibits salivation and results in dry mouth Pharynx and Esophagus Pharynx Consists of the nasopharynx, oropharynx, and laryngopharynx Food and fluids to the esophagus Air to the trachea Esophagus Connects the pharynx to the stomach The upper and lower esophageal sphincters regulate movement
6 6 Swallowing During the voluntary phase of swallowing, a bolus of food is moved by the tongue from the oral cavity to the pharynx The pharyngeal phase is a reflex caused by the stimulation of stretch receptors in the pharynx The soft palate closes the nasopharynx, and the epiglottis, vestibular folds, and vocal folds close the opening into the larynx Pharyngeal muscles move the bolus to the esophagus The esophageal phase is a reflex initiated by the stimulation of stretch receptors in the esophagus. A wave of contraction (peristalsis) moves the food to the stomach Digestive System Part II Stomach, Small Intestine, Liver Stomach Anatomy and Histology Temporary storage tank where chemical breakdown of proteins begins and food is converted from a bolus to chyme The openings of the stomach are the Gastroesophageal opening to the esophagus Pyloric orifice to the duodenum The major regions are the Cardiac part Fundus Body Pyloric part which is continuous with the duodenum through the pyloric sphincter The lateral sides of the stomach consist of greater and lesser curvatures
7 7 Stomach Anatomy and Histology The wall of the stomach consists of External serosa Muscle layer (longitudinal, circular, and oblique) Submucosa Simple columnar epithelium Surface mucous cells: produce an alkaline mucous with bicarbonate, which coats and protects the stomach lining An empty stomach has a volume of 50 ml but can hold about a gallon of food When empty one can see the folds called rugae (submucosa and mucosa) Stomach Anatomy and Histology There are gastric pits with glands that produce juice Glands include four secretory cells: Mucous neck: secrete acid mucus Parietal cells: secrete HCl and intrinsic factor Chief cells: produce pepsinogen Pepsinogen is activated to pepsin by: HCl in the stomach Pepsin itself via a positive feedback mechanism Endocrine cells: produce regulatory hormones Gastrin, histamine, endorphins, serotonin, cholecystokinin (CCK), and somatostatin into the lamina propria Stomach Secretions
8 8 Chyme is ingested food mixed with gastric juice Gastric juice Mucus protects the stomach lining Pepsinogen is converted to pepsin, which digests proteins Hydrochloric acid promotes pepsin activity and kills microorganisms Intrinsic factor is necessary for vitamin B12 absorption Gastrin and histamine regulate stomach secretions A proton pump (H + K + exchange pump) moves H + out of parietal cells Regulation of Stomach Secretion There are three phases of stomach secretion Cephalic phase Initiated by the sight, smell, taste, or thought of food Nerve impulses from the medulla stimulate hydrochloric acid, pepsinogen, gastrin, and histamine secretion Gastric phase Initiated by distention of the stomach, which stimulates gastrin secretion and activates CNS and local reflexes that promote secretion Gastrointestinal phase Acidic chyme, which enters the duodenum and stimulates neuronal reflexes and the secretion of hormones (secretin, cholecystokinin) that inhibit gastric secretions Small Intestine
9 9 The body s major digestive organ Digestion is completed and absorption occurs Runs from pyloric sphincter to the ileocecal valve Has three subdivisions: Duodenum ~ 10 long. The bile and pancreatic ducts empty here Jejunum ~ 8 long Ileum ~ 12 long Small Intestine Anatomy and Histology Structural modifications of the small intestine wall increase surface area about 600 fold Circular folds Deep folds of the mucosa and submucosa Villi Fingerlike extensions of the mucosa Microvilli Tiny projections of absorptive mucosal cells plasma membranes This forms a brush border The epithelium of the mucosa is simple columnar epithelium. Between the villi the mucosa contains pits called intestinal glands Small Intestine Anatomy and Histology The epithelium of the mucosa is made up of: Absorptive cells Produce digestive enzymes Goblet cells Produce a protective mucus Granular cells (Paneth cells) Protect the intestinal epithelium from bacteria Endocrine cells Produce regulatory hormones Peyer s patches (aggregated lymphoid follicles) are found in the submucosa
10 10 Small Intestine Secretions Mucus protects against digestive enzymes and gastric acids Digestive enzymes (disaccharidases and peptidases) are bound to the intestinal wall Chemical or tactile irritation, vagal stimulation, and secretin stimulate intestinal secretion Movement of the Small Intestine Segmental contractions mix intestinal contents Peristaltic contractions move materials distally Distension of the intestinal wall, local reflexes, and the parasympathetic nervous system stimulate contractions Distension of the cecum initiates a reflex that stimulates contraction of the ileocecal sphincter
11 11 Liver Anatomy and Histology The liver has four external lobes: right, left, caudate, and quadrate Internally, the liver is divided into eight segments Liver segments are divided into lobules Hexagonal shaped liver lobules are the structural and functional units of the liver Composed of hepatocyte (liver cell) plates radiating outward from a central vein Portal triads are found at each of the six corners of each liver lobule
12 12 Liver Anatomy and Histology Portal triads consist of Hepatic duct: conduct bile toward the duodenum Hepatic artery: supplies oxygen rich blood to the liver Hepatic portal vein: carries venous blood with nutrients from digestive viscera The hepatic cords are composed of columns of hepatocytes separated by the bile canaliculi Sinusoids are enlarged spaces filled with blood and lined with endothelium and hepatic phagocytic cells Kupffer cells: hepatic macrophages found in liver sinusoids Functions of the Liver Produces bile, which contains bile salts that emulsify fats Stores and processes nutrients, produces new molecules, and detoxifies molecules Hepatic phagocytic cells phagocytize red blood cells, bacteria, and other debris Produces blood components Blood Flow Through the Liver Branches of the hepatic artery and the hepatic portal vein in the portal triads empty into hepatic sinusoids Hepatic sinusoids empty into central veins, which join to form the hepatic veins, which leave the liver
13 13 Digestive System Part III Bile Production, Pancrase, Large Intestine Gallbladder and Bile Gallbladder Bile A small sac on the inferior surface of the liver Stores and concentrates bile A yellow green, alkaline solution containing bile salts, bile pigments, cholesterol, neutral fats, phospholipids, and electrolytes Bile salts are cholesterol derivatives that: Emulsify fat Facilitate fat and cholesterol absorption Helps make cholesterol soluble The chief bile pigment is bilirubin, a waste product of heme. Bilirubin is metabolized by bacteria in the small intestines and urobilin is produced, which gives feces its dark color Regulation of Bile Secretion Acidic, fatty chyme causes the duodenum to release: Cholecystokinin (CCK) and secretin into the bloodstream Cholecystokinin causes: The gallbladder to contract and releases bile Secretin increases bile secretion (water and bicarbonate ions) Bile salts and secretin transported in blood stimulate the liver to produce bile Vagal stimulation causes weak contractions of the gallbladder
14 14 Pancreas Anatomy and Histology Location Lies deep to the greater curvature of the stomach The head is encircled by the duodenum and the tail sits against the spleen Exocrine function Secretes pancreatic juice which breaks down all categories of foodstuff The pancreas is divided into lobules that contain acini Clusters of secretory cells that contain zymogen granules with digestive enzymes Connect to a duct system that eventually forms the pancreatic duct The pancreas also has an endocrine function The islets of Langerhans release of insulin and glucagon
15 15 Pancreatic Secretions The aqueous component of pancreatic juice contains bicarbonate ions Water solution of enzymes and electrolytes (primarily HCO 3 ) Neutralizes acidic chyme Provides optimal environment for pancreatic enzymes The enzymatic component of pancreatic juice is produced by the acini and contains enzymes that digest carbohydrates, lipids, and proteins Enzymes are released in inactive form and activated in the duodenum Large Intestine Anatomy and Histology Extends from the ileocecal valve to the anus Absorbs water and eliminate the waste via feces Is subdivided into the cecum, appendix, colon, rectum, and anal canal The cecum forms a blind sac at the junction of the small and large intestines. The vermiform appendix is a blind tube off the cecum. The colon has distinct regions: ascending colon, transverse colon, descending colon, and sigmoid colon The sigmoid colon joins the rectum The anal canal, the last segment of the large intestine, opens to the exterior at the anus The anal canal contains two sphincters to allow the movement of feces Anatomy and Histology of the Large Intestine Three unique features Teniae coli: three bands of longitudinal smooth muscle in its muscularis Haustra: pocketlike sacs caused by the tone of the teniae coli Epiploic appendages : fat filled pouches of visceral peritoneum The mucosal lining of the large intestine is simple columnar epithelium with mucus producing crypts
16 16 Large Intestine Secretions Mucus protects the intestinal lining The bacterial flora of the large intestine consist of: Bacteria surviving the small intestine that enter the cecum Those entering via the anus These bacteria: Colonize the colon Ferment indigestible carbohydrates Release irritating acids and gases (flatus) Synthesize B complex vitamins and vitamin K Constitute about 30% of the dry weight of the feces Movement in the Large Intestine Haustra mix the contents and moves them slowly toward the anus Mass movements are strong peristaltic contractions that occur three or four times a day Defecation is the elimination of feces Distension of rectal walls caused by feces: Stimulates contraction of the rectal walls Relaxes the internal anal sphincter Reflex activity moves feces through the internal anal sphincter Voluntary activity regulates movement through the external anal sphincter Digestive System Part IV Digestion and Metabolism Digestion, Absorption, and Transport Digestion (mechanical and chemical) is the breakdown of organic molecules into their component parts Chemical digestion is the breaking of covalent chemical bonds in organic molecules by digestive enzymes Absorption is the uptake of digestive tract contents Transport is the distribution of nutrients throughout the body Chemical Digestion Carbohydrate digestion Begins in mouth with salivary amylase digesting starches Pancreatic amylase finishes the process in the small intestine. Simple sugars are also broken down here
17 17 Protein digestion Lipid digestion Broken down into amino acids Begins in the stomach with pepsin Trypsin and chymotrypsin are also important protein digesting enzymes. Nucleic acids Broken down by pancreatic nucleases in the small intestine Small intestine is the sole source of lipid digestion by lipases Enter lacteals and are transported to systemic circulation via lymph Carbohydrates Include starches, glycogen, sucrose, lactose, glucose, and fructose Polysaccharides are broken down into monosaccharides by a number of different enzymes Monosaccharides Taken up by intestinal epithelial cells by symport that is powered by a Na + gradient or by facilitated diffusion Carried to the liver, where the non glucose sugars are converted to glucose Glucose is transported to the cells that require energy Glucose enters the cells through facilitated diffusion Insulin influences the rate of glucose transport Lipids Include triglycerides, phospholipids, steroids, and fat soluble vitamins Emulsification is the transformation of large lipid droplets into smaller droplets and is accomplished by bile salts Lipase digests lipid molecules to form fatty acids and a monoglyceride Micelles form around lipid digestion products and move to epithelial cells of the small intestine, where the products pass into the cells by simple diffusion Lipids Within the epithelial cells, free fatty acids are combined with monoglycerides to form triglycerides Proteins coat triglycerides, phospholipids, and cholesterol to form chylomicrons Chylomicrons enter lacteals within intestinal villi and are carried through the lymphatic system to the bloodstream Triglycerides are stored in adipose tissue, converted into other molecules, or used as energy
18 18 Lipoproteins Lipoproteins include chylomicrons, VLDL, LDL, and HDL LDL transports cholesterol to cells, and HDL transports it from cells to the liver LDL are taken into cells by receptor mediated endocytosis, which is controlled by a negative feedback mechanism Proteins Pepsin in the stomach breaks proteins into smaller polypeptide chains Proteolytic enzymes from the pancreas produce small peptide chains Peptidases, bound to the microvilli of the small intestine, break down peptides Tripeptides, dipeptides, and amino acids are absorbed by symport that is powered by a Na gradient Amino acids are transported to the liver, where the amino acids can be modified or released into the bloodstream Amino acids are actively transported into cells under the stimulation of growth hormone and insulin Amino acids are used as building blocks or for energy Amino Acid Transport Across the Intestinal Epithelium Water and Ions About 9 liters of water enters the digestive tract each day Can move in either direction across the wall of the small intestine, depending on the osmotic gradients across the epithelium Epithelial cells actively transport Na, K, Ca 2+, and Mg 2+ from the intestine Chloride ions move passively through the wall of the duodenum and jejunum but are actively transported from the ileum
19 19 Stages of Metabolism Processing of nutrients Digestion, absorption and transport to tissues Cellular processing (in cytoplasm) Synthesis of lipids, proteins, and glycogen, or Catabolism (glycolysis) into intermediates Oxidative (mitochondrial) breakdown of intermediates into CO2, water, and ATP
20 20
The Digestive System. Chapter 16. Introduction. Histological Organization. Overview of Digestive System. Movement and Mixing of Digestive Materials
The Digestive System Chapter 16 Introduction Structure of the digestive system A tube that extends from mouth to anus Accessory organs are attached Functions include Ingestion Movement Digestion Absorption
More informationAlimentary canal (gastrointestinal or GI tract) continuous coiled hollow tube
The Digestive System and Body Metabolism Gross Anatomy Function The Digestive System Functions Ingestion taking in food Digestion breaking food down both physically and chemically Absorption movement of
More information5. Secretion: release of water, acids. Enzymes, buffers by digestive tract.
Digestive System CH-16 Lecture topics Functions of the digestive system: p. 488. 1. Ingestion: Taking food in 2. Propulsion: movement of food thru alimentary canal p.490. voluntary: swalloing : skeletal
More informationOutline Digestive System
Outline Digestive System The Digestive System Digestive System Lecture Packet 19 Chapter 15 I. Function II. Layers of the GI tract III. Major parts: mouth, pharynx, esophagus, stomach, small intestine,
More informationThe Gastrointestinal System It consists of: The digestive tract Mouth Pharynx Oesophagus Stomach Small intestine Large intestine
The Gastrointestinal System It consists of: The digestive tract Mouth Pharynx Oesophagus Stomach Small intestine Large intestine The digestive organs Teeth Tongue Salivary glands Liver Gall bladder Pancreas
More informationThe Digestive System. Chapter 15
The Digestive System Chapter 15 Introduction Digestion refers to the mechanical and chemical breakdown of food so the nutrients can be absorbed by cells Carried out by the digestive system Consists of
More informationFunctions of the GI Tract. Chapter 18. Functions of the GI Tract (continued)
Functions of the GI Tract Chapter 18 The Digestive System Motility: Movement of of food through the GI tract. Ingestion: Taking food into the mouth. Mastication: Chewing the food and mixing it with saliva.
More informationDivisions of Digestive System. Organs of the Alimentary Canal. Anatomy of the Digestive System: Organs of the Alimentary Canal. CHAPTER 14 p.
Divisions of Digestive System Anatomy of the Digestive System: Organs of the Alimentary Canal CHAPTER 14 p. 412-423 1. Alimentary Canal or Gastrointestinal Tract (GI)-digests and absorbs food coiled hollow
More informationThe Digestive System. Chapter 14. The Digestive System and Body Metabolism. Metabolism. Organs of the Digestive System. Digestion.
Chapter 14 The Digestive System The Digestive System and Body Metabolism Digestion of ingested food of nutrients into the blood Metabolism Production of Constructive and degradative cellular activities
More informationDigestive System AKA. GI System. Overview. GI Process Process Includes. G-I Tract Alimentary Canal
Digestive System AKA G-I Tract Alimentary Canal Overview GI System Consists of Mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus About 30 in length Accessory Organs Teeth, tongue,
More informationDigestive System Functions
Digestive System Functions A. Gastrointestinal Processes 1. Ingestion: placing food in mouth (voluntary) 2. Propulsion: moving food through GI tract a. Peristalsis: alternating waves of contraction and
More informationThe Vertebrate (mostly human) Digestive System
The Vertebrate (mostly human) Digestive System Mouth - mastication, lubrication, digestion Pharynx and Esophagus - swallowing Stomach - some digestion Small intestine - most digestion and absorption Large
More informationThe Digestive System
The Digestive System Digestive Structures Mouth including teeth and tongue Esophagus Stomach Small intestine Large intestine Accessory structures - salivary glands, liver, gallbladder, & pancreas Digestive
More information26. Digestive System
26. Digestive System Your body needs food for two primary purposes: growth and maintenance. Molecules and atoms in the food you eat are generally used to either build new molecules in your body or to provide
More informationBiology 2402 Anatomy &Physiology II - Digestive system notes - Ch. 15
Biology 2402 Anatomy &Physiology II - Digestive system notes - Ch. 15 Digestive system processes the food used as fuel and nutrients for the body. Composed of a tube through the body (digestive tract,
More informationMedical Physiology Z.H.Al-Zubaydi
Lec.13 Medical Physiology Z.H.Al-Zubaydi Functions of the Digestive System The major functions of the digestive tract include the following six processes, summarized in Figure 1: 1. Ingestion Food must
More informationCHAPTER 23 DIGESTIVE
CHAPTER 23 DIGESTIVE nutrition requires : getting nutrients digesting nutrients transporting nutrients Digestive System musculo-skeletal digestive circulatory Digestive System alimentary canal ~ gastrointestinal
More informationChapter 15 Digestive System.
Chapter 15 Digestive System. I. The Gastrointestinal Tract. a. The digestive system mechanically and chemically breaks down food into molecules that can be absorbed into the bloodstream or lymph. Residues
More informationGI TRACT ORGANS ACCESSORY ORGANS
Digestive System GI TRACT ORGANS Oral cavity Oropharynx Esophagus Stomach Small intestine Large Intestine Anus ACCESSORY ORGANS Salivary glands Pancreas Liver Gall bladder GI TRACT LAYERS Mucosa Submucosa
More informationDigestive System. Gross Anatomy and Physiology
Digestive System Gross Anatomy and Physiology I. Introduction A. Base Function: Working with the circulatory system the digestive system provides the body with fuel. B. Main players: 1. Digestive tract:
More informationMechanical digestion: physical breaking of food chewing by teeth churning by stomach segmentation by intestines (= mixing food) p.611/ Fig. 22.
The Digestive System 1. Describe the general functions of the digestive system Ingestion: Taking food in Propulsion: movement of food thru alimentary canal voluntary: swalloing involuntary: peristalsis
More informationThe Human Digestive System
The Human Digestive System Name: Section: Date: Page 1 of 10 Page 2 of 10 Page 3 of 10 Page 4 of 10 Page 5 of 10 Page 6 of 10 Putting it All Together Digestive Enzymes Page 7 of 10 Page 8 of 10 Page 9
More informationSEER Training Modules
http://training.seer.cancer.gov/anatomy/digestive/ WiRED International wishes to thank the National Cancer Institute for use of this information. SEER Training Modules Introduction to the Digestive System
More informationChapter 17 Digestive System. Alimentary Canal. Movements of the Tube
Chapter 17 Digestive System Functions of Digestive System ingestion mechanical digestion chemical digestion propulsion absorption defecation Consists of the alimentary canal and accessory organs 1 Alimentary
More informationEach gland has at least one duct that takes saliva to the oral cavity.
kufa university Physiology College of Nursing first year student Ass. Lect :- Hisham Qassem M. Lecture No :-3 The Digestive System Digestive system consists of: 1. Gastrointestinal Tract (GIT). 2. Accessory
More informationChapter 24: DIGESTIVE SYSTEM
Chapter 24: DIGESTIVE SYSTEM I. OVERVIEW A. Gross anatomy (Fig. 24.1) and functions (Table 24.1) B. "You are what you eat." 1. The problem: Ingestion (eating) is not the same as absorption. 2. The solution:
More informationTHE GI TRACT IS A CONTINUOUS MULTILAYERED TUBE EXTENDING FROM THE MOUTH TO THE ANUS THAT IS SUPPORTED AND PARTIALLY COVERED BY THE PERITONEUM.
THE GI TRACT IS A CONTINUOUS MULTILAYERED TUBE EXTENDING FROM THE MOUTH TO THE ANUS THAT IS SUPPORTED AND PARTIALLY COVERED BY THE PERITONEUM. OVERVIEW OF THE DIGESTIVE SYSTEM Two groups of organs compose
More information10.2 The Human Digestive System pg. 411
10.2 The Human Digestive System pg. 411 The human digestive system is made up of a group of organs working together. The digestive tract is made up of the mouth, esophagus, stomach, small intestine, and
More informationDigestion, Absorption. How & where?
Digestion, Absorption How & where? What happens to food? Three processes Digestion Absorption Elimination Where do they occur? GI tract Overview of Digestion GI tract Gastrointestinal (GI) tract: series
More informationSMALL AND LARGE INTESTINE SECRETIONS
SMALL AND LARGE INTESTINE SECRETIONS Objectives At the end of lecture student should be able to know, Digestive system Digestive system secretions Small intestine Component of small intestine Intestinal
More informationThe Digestive System. You are what you eat!
The Digestive System You are what you eat! Try to label the diagram (PENCIL!!) What is Digestion? Digestion: the breakdown of large macromolecules (proteins, fats, carbohydrates) into smaller molecules
More informationDigestive System Digestive Tract
Digestive System Digestive Tract Dept. of Histology and Embryology 周 莉 教 授 Introduction of digestive system * a long tube extending from the mouth to the anus, and associated with glands. * its main function:
More informationDigestive System. Digestive System. Digestive tract. Accessory organs. Digestive System Overview
Digestive System Digestive System The process of chemically and physically breaking down foods into simpler forms that can be absorbed is called digestion. The digestive system can be divided into two
More informationDigestive system. Dr. Carmen E. Rexach Anatomy 35 Mt San Antonio College
Digestive system Dr. Carmen E. Rexach Anatomy 35 Mt San Antonio College Oral cavity Alimentary Canal Accessory organs teeth salivary glands liver gall bladder pancreas appendix Components Functions Motility
More informationDigestive System Notes
Digestive System Notes Structure Function Relation Mouth cavity Mechanical digestion by teeth; chemical digestion of starch by saliva. Salivary glands Three pairs of glands which secrete saliva containing
More informationChapter 15 Digestion and Nutrition
Chapter 15 Digestion and Nutrition Digestive System: Digestion refers to the mechanical and chemical breakdown of foods so that nutrients can be absorbed by cells. Consists of the canal which is all of
More informationChapter 49 - Nutrients and the Digestive System I. Nutrients (chemical substances necessary for organisms to grow and function properly)
Chapter 49 - Nutrients and the Digestive System I. Nutrients (chemical substances necessary for organisms to grow and function properly) 6 basic nutrients - 4 food groups (milk, meat, fruit and vegetable,
More informationI. The basic function of the digestive system is
Chapter 15, Digestive System - ANATOMY OF THE DIGESTIVE SYSTEM I. The basic function of the digestive system is. This process is called. II. List 2 other names for the digestive tract: A. B. III. The digestive
More informationContinuing Education Independent Study Series
Continuing Education Independent Study Series Professional Development Manager Association of Surgical Technologists Englewood, Colorado Association of Surgical Technologists Publication made possible
More informationTHE DIGESTIVE SYSTEM Secretion Graphics are used with permission of: Pearson Education Inc., publishing as Benjamin Cummings (http://www.aw-bc.
THE DIGESTIVE SYSTEM Secretion Graphics are used with permission of: Pearson Education Inc., publishing as Benjamin Cummings (http://www.aw-bc.com) Page 1: Title Page Digestive system secretion involves
More informationDigestion, Absorption. How & where?
Digestion, Absorption How & where? What happens to food? Three processes Digestion Absorption Elimination Where do they occur? GI tract Overview of Digestion GI tract Gastrointestinal (GI) tract: series
More informationDigestion. What we ll cover. Main stages of digestion. Digestion: A Closer Look. A Tour of the Human Digestive System. Mechanical digestion
Digestion What we ll cover What are the digestive system structures and their functions? Where does carbohydrate, protein and fat digestion and absorption occur? What are the 3 accessory organs of digestion?
More informationThe Digestive System
16 The Digestive System FOCUS: The function of the digestive system is to take in food, break it down into smaller compounds, and absorb those compounds so that the body can use them. This process provides
More informationDigestive system Review
Digestive system Review 1. Distinguish between chemical digestion and mechanical digestion. The physical breakdown of food begins in the mouth with two types of processes. The mouth is a complex structure
More informationName Digestive System and Body Metabolism Notes Ch 14
Name Digestive System and Body Metabolism Notes Ch 14 Digestion Breakdown of ingested food Absorption of nutrients into the blood Metabolism Production of cellular energy ( ) Constructive and degradative
More informationClassifications of animals: ruminant vs non-ruminant carnivore: meat-eating herbivore: plant-eating omnivore: both meat and plant-eating
Digestion and Metabolism Digestive tract one long, continuous tube starting at the mouth and ending at the anus Functions Ingestion Grinding Digestion/absorption of food Elimination of solid wastes Classifications
More informationGeneral Structure and Function of the Digestive System
General Structure and Function of the Digestive System Do Now Why does food have to be digested before cells can use it? What are the typical four layers of the digestive tract wall? What is the name of
More informationDigestion. Processing of food Types. Mechanical (physical) Chemical. Chew Tear Grind Mash Mix. Catabolic reactions Enzymatic hydrolysis
Digestive System Digestion Processing of food Types Mechanical (physical) Chew Tear Grind Mash Mix Chemical Catabolic reactions Enzymatic hydrolysis Carbohydrate Protein Lipid 2 Digestion Phases Ingestion
More informationDIGESTIVE SYSTEM Five Basic Processes The Gastrointestinal tract (alimentary canal)
DIGESTIVE SYSTEM Five Basic Processes 1. Ingestion - eating 2. Movement of the food along the G.I. tract. 3. Digestion- chemical and mechanical breakdown of food. 4. Absorption of the breakdown products
More informationEating, pooping, and peeing THE DIGESTIVE SYSTEM
THE DIGESTIVE SYSTEM Ingested food is not technically in the body until it is absorbed so it needs to be: Mechanically and chemically reduced Transported by the blood to the cells Large portions are not
More informationDigestive System. Student Learning Objectives: Structures to be studied: Introduction
Digestive System Student Learning Objectives: Identify the primary structures of the digestive system. Describe the use of various important nutrient materials in the body. Structures to be studied: Oral
More informationSession 20. The Digestive Organs. Session Outline. Introduction. Unit 6 Digestive System
Unit 6 Digestive System Session 20 The Digestive Organs Session Outline Introduction 20.1Alimentary tract 20.2 Mouth 20.3Tongue 20.4Teeth 20.5Oesophagus 20.6 Stomach 20.7Small intestine 20.8 large intestine
More informationFunctions of the digestive system
Digestive system Functions of the digestive system Digestion-mechanical and chemical breakdown of material Motility-movement of material from the oral cavity to the anus-swallowing / peristalsis Secretion-exocrine
More informationII. General Characteristics of the Alimentary Canal
Human Anatomy & Physiology 17 Be sure to watch the Video: The Digestive System. Digestive System URLs http://www.emc.maricopa.edu/faculty/farabee/biobk/ BioBookDIGEST.html http://yahooligans.yahoo.com/reference/gray/244.html
More informationSpecial organ structures and functions conduct these tasks through the successive parts of the overall system.
Chapter 5 Digestion, Absorption, and Metabolism Chapter 5 Lesson 5.1 Key Concepts Through a balanced system of mechanical and chemical digestion, food is broken down into smaller substances and the nutrients
More informationii. Palatine tonsils - located between glossopalatine arch and pharyngopalatine arch iii. Function: guide food and air to laryngopharynx III.
Digestive System I. Introduction I. Tube from mouth to anus, 30 ft. long II. Greatest portion below diaphragm III. Function: digestion and absorption II. Cross section through the coelom (body cavity)
More information23.4 Digestive System
23.4 Digestive System The Pancreas & Pancreatic Regulation Regulation of Bile Secretions The Small Intestine The Large Intestine Pancreas Location Mostly retroperitoneal Deep to greater curvature of stomach
More informationChapter 22: Digestive System
Chapter 22: Digestive System Converts food into raw materials necessary for cell maintenance and growth Digestive System: Main Divisions of Digestive System: 1) Alimentary Canal (gastrointestinal tract)
More informationThe Digestive System. - teeth, tongue, gall bladder, and glands (salivary glands, liver, pancreas).
The Digestive System I. Overview A. Organs of the digestive system. 1. Alimentary canal (GI Tract): - continuous muscular tube, open at both ends. - digests food, absorbs digested fragments. 2. Accessory
More informationChapter 48. Nutrients in Food. Carbohydrates, Proteins, and Lipids. Carbohydrates, Proteins, and Lipids, continued
Carbohydrates, Proteins, and Lipids The three nutrients needed by the body in the greatest amounts are carbohydrates, proteins, and lipids. Nutrients in Food All of these nutrients are called organic compounds,
More informationHuman Anatomy & Physiology II with Dr. Hubley
Human Anatomy & Physiology II with Dr. Hubley Practice Exam III Name: Instructions This exam consists of 50 questions. You may write on the exam itself, but be sure to answer all your questions on a Scantron
More informationPhysiology of Digestive system II
Small Intestine Physiology of Digestive system II Motility of small intestine: Distention of the Small Intestine Elicits Mixing Contractions Called Segmentation Contractions. These are concentric contractions
More informationThe Excretory and Digestive Systems
The Excretory and Digestive Systems 38.2 The Process of Digestion Organs of the Digestive System The digestive system includes the: Mouth Pharynx Esophagus Stomach Small and large intestine. Other structures
More informationDIGESTIVE SYSTEM Liver, pancreas, esophagus, stomach fundus, small intestine, large intestine, appendix; preparations B9, 10, 12, 15, 16, 17, 18, (19)
DIGESTIVE SYSTEM Liver, pancreas, esophagus, stomach fundus, small intestine, large intestine, appendix; preparations B9, 10, 12, 15, 16, 17, 18, (19) Institute of Histology and Embryology RNDr. Lucie
More informationWelcome back. Today, we embark on Lesson 6 where we ll study the human digestive system.
Basic Human Anatomy Lesson 6: The Human Digestive System Welcome back. Today, we embark on Lesson 6 where we ll study the human digestive system. After completing this lesson, you should be able to define
More informationDigestive System Module 7: Chemical Digestion and Absorption: A Closer Look
OpenStax-CNX module: m49457 1 Digestive System Module 7: Chemical Digestion and Absorption: A Closer Look Donna Browne Based on Chemical Digestion and Absorption: A Closer Look by OpenStax This work is
More informationDigestive System Why is digestion important? How is food digested? Physical Digestion and Movement
Digestive System The digestive system is made up of the digestive tract a series of hollow organs joined in a long, twisting tube from the mouth to the anus and other organs that help the body break down
More informationIntegumentary System Digestive System. Outline. Integumentary System 11/4/2008. Week 11 BA & BP November 4, 2008 Nadia Arora, ND
Integumentary System Digestive System Week 11 BA & BP November 4, 2008 Nadia Arora, ND Outline Integumentary system and body membranes Types of body membranes and their function General structure and main
More informationDigestive system. Dr. Carmen E. Rexach Physiology Mt San Antonio College
Digestive system Dr. Carmen E. Rexach Physiology Mt San Antonio College Functions Motility ingestion mastication deglutition peristalsis Secretion exocrine endocrine Digestion Absorption Tunics Innervation
More informationSmall & Large Intestines
Small & Large Intestines Small Intestine: principal site for digestion of food and absorption of the products of digestion Large Intestine: reabsorption of water and elimination of undigested food and
More informationStudy Guide Digestive System
Study Guide Digestive System 1. Digestion is breakdown of complex food molecules like starch into smaller molecules like glucose that can pass through the cell membranes of intestine and get absorbed into
More information2) Digestion the breakdown of. There are two types of digestion: Mechanical and Chemical. 3) Absorption when the nutrients enter into the blood.
The Digestive System Video on the digestive system (5 min) The digestive system is responsible for the breakdown of the we eat so that it can be absorbed into the. There are four main stages of the digestive
More informationIntroduction. Digestive System. Physiology. Anatomy. Physiology. Alimentary Canal. Chapter 21
Chapter 21 Digestive System Susan G. Salvo Introduction Digestive process is a disassembly line Digestive system provides processes in which proteins, carbohydrates, and fats are broken down and used a
More informationCHAPTER 17: DIGESTIVE SYSTEM. 2. Distinguish between mechanical digestion and chemical digestion.
CHAPTER 17: SYSTEM OBJECTIVES 1. Define the term digestion and explain its significance. 2. Distinguish between mechanical digestion and chemical digestion. 3. Discuss the five digestive processes that
More informationChapter 2 Digestion and Absorption Chapter Outline
Chapter 2 Digestion and Absorption Chapter Outline I. Anatomy of the Digestive Tract A. The Digestive Organs 1. Mouth to the Esophagus 2. Esophagus to the Stomach 3. The Small Intestine 4. The Large Intestine
More informationTHE DIGESTIVE SYSTEM
THE DIGESTIVE SYSTEM What is digestion? Digestion is the process of breaking down food so that it's small enough to be absorbed and used by the body for energy or in other bodily functions. Digestion involves
More informationThe 6 th International Junior Science Olympiad Training Programme
The 6 th International Junior Science Olympiad Training Programme KEEPING HEALTHY SECTION 2: DIGESTIVE SYSTEM Notes to Teachers Learning Objectives: Processes of nutrition in human (0.25 hr) General plan
More informationDigestive System (Chapter 24) Lecture Materials for Amy Warenda Czura, Ph.D. Suffolk County Community College Eastern Campus
Digestive System (Chapter 24) Lecture Materials for Amy Warenda Czura, Ph.D. Suffolk County Community College Eastern Campus Digestive System Responsible for providing raw materials to support life: -food
More information1. Essay: The Digestive and Absorption Processes of Macronutrients
Jenny Kim Professor Rosario Nutrition: Macronutrients Project June 26, 2014 1. Essay: The Digestive and Absorption Processes of Macronutrients Whenever we eat, the foods we ingest in our bodies undergo
More information1. gustatory cells: Surface cells in the throat and on the taste buds in the mouth that transmit
Chapter 3 Digestion and Absorption Key Terms 1. gustatory cells: Surface cells in the throat and on the taste buds in the mouth that transmit taste information. 2. absorption: The movement of substances
More informationCH 23 THE DIGESTIVE SYSTEM
CH 23 THE DIGESTIVE SYSTEM This system is responsible for processing nutrients, which are required in order to produce energy and chemical building blocks via cellular respiration for cellular growth,
More information8. Be able to label a diagram of an earthworm. Know the function of each of the major parts of the earthworm.
Review for Unit Test: The Digestive System 1. Know the meaning of these terms: heterotrophs digestion peristalsis microvilli autotrophs chemical digestion chyme lacteal intracellular digestion mechanical
More informationThe Digestive System
The Digestive System Objectives Name and locate the digestive organs and the accessory organs of digestion. List the general function of the digestive system and the function of each organ. Define mechanical
More information22 Digestive System. Taft College Human Physiology
22 Digestive System Taft College Human Physiology Functions of the Digestive System (4 Basic Functions of Digestion) 1. Ingestion - food intake. 2. Digestion - process of reducing foods to their constituent
More informationWeds 5/20/15. Membranes - finish last lecture outline. Digestive System Nutrition Types of digestion & digestive systems Vertebrate digestive system
Membranes - finish last lecture outline Weds 5/20/15 Digestive System Nutrition Types of digestion & digestive systems Vertebrate digestive system structures and functions // accessory organs mechanism
More informationThe Digestive System 24-1
The Digestive System 24-1 Overview of GI tract Functions Mouth---bite, chew, swallow Pharynx and esophagus---- transport Stomach----mechanical disruption; absorption of water & alcohol Small intestine--chemical
More informationChapter 25. The Stomach Microscopic Anatomy and Gastric Function
Chapter 25 The Stomach Microscopic Anatomy and Gastric Function Gross Anatomy of Stomach Diaphragm Lesser omentum Lesser curvature Pyloric region: Antrum Pyloric canal Pylorus Pyloric sphincter Fundic
More informationTopic 4: Digestion and Nutrition
Topic 4: Digestion and Nutrition THE CONTENTS OF FOOD Food contains nutrients: Nutrients include: 1. 2. 3. 4. 5. Nutrients must be small enough to enter our cells. If they are too large they must be digested
More informationAbsorption and Transport of Nutrients
Page1 Digestion Food travels from mouth esophagus stomach small intestine colon rectum anus. Food mixes with digestive juices, moving it through the digestive tract Large molecules of food are broken into
More informationDigestion in the small and Large Intestines
9.5 Digestion in the small and Large Intestines Do some foods keep you feeling full for a long time? Do you ever feel that after eating certain foods, you are hungry again in a short time? Some foods stay
More informationAP Biology. What do animals need to live? Animal Nutrition. Nutritional requirements. How do animals get their food? Different diets; different lives
Animal Nutrition What do animals need to live? Animals make energy using: food food oxygen Animals build bodies using: food for raw materials amino acids, sugars, fats, nucleotides O 2 ATP energy for synthesis
More informationDigestive Processes - A Short Summary
Digestive System: Chapter 24 All living organisms need nutrients for anabolic and catabolic processes Anabolic Catabolic 2 Types of Organs: 1. Alimentary Canal (GI tract) Muscular tube (smooth muscle)
More informationLecture Notes on the Digestive System
Lecture Notes on the Digestive System Function The function of the digestive system is to digest and absorb food. It consists of a tubular gastrointestinal tract and accessory organs that aid in digestion
More informationHorse Science: The Digestive System of the Horse Page 3
Horse Science: The Digestive System of the Horse Page 3 The digestive system of the horse is different from that Mastication (chewing) is the mechanical reduction of of the other farm animals. Although
More informationHuman Digestive System Anatomy
Human Digestive System Anatomy Biology 104 Objectives: 1. Learn the anatomy of the digestive system. You should be able to find all terms in bold on the human torso models. 2. Relate structure of the system
More informationChapter 5. Maintenance of the Human Body. Digestive System and Nutrition. Chapter Concepts
P A R T II Maintenance of the Human Body 5 Digestive System and Nutrition 77 6 Composition and Function of the Blood 105 7 Cardiovascular System 121 8 Respiratory System 143 9 Urinary System and Excretion
More informationPlants and other photosynthetic organisms can produce
51 Fueling Body Activities: Digestion Concept Outline 51.1 Animals employ a digestive system to prepare food for assimilation by cells. Types of Digestive Systems. Some invertebrates have a gastrovascular
More informationThe Respiratory System
Human Anatomy III: Respiratory, Urinary & Digestive Systems The Respiratory System Major functions include: Obtaining oxygen Removing carbon dioxide Maintenance of ph balance Respiration may be accomplished
More informationTopic 3.0 Healthy human function depends on a variety of interacting and reacting systems
Topic 3.0 Healthy human function depends on a variety of interacting and reacting systems Organ Systems Organ systems must have the ability to to changes within and outside of your body to maintain life
More informationDigestive system - how food is digested
ARTICLES Digestive system - how food is digested Przeczytaj pełną wersję artykułu: http://www.healthynutritionguide.info/nutrition/articles/art,digestive-system-how-food-isdigested.html Digestion is the
More information