Eric Soza, Nick Soto, Andres Padilla Period 2 2/10/15.
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Transcript of Eric Soza, Nick Soto, Andres Padilla Period 2 2/10/15.
Eric Soza, Nick Soto, Andres Padilla
Period 2
2/10/15
Alimentary CanalExtends from the mouth to the anus, includes
accessory organs Mouth, pharynx, esophagus, stomach, small
intestine, large intestine, and anal canal Accessory organs- salivary glands, liver,
gallbladder, and pancreas About 8 meters long 4 layers
MucosaSubmucosaMuscular layerSerosa
Segmentation and Peristalsis
Mouth 1st portion of alimentary canalReceives food, begins digestion Mastication
Cheeks and LipsForm lateral walls of mouth Subcutaneous fatMuscles associated with chewing Stratified squamous epithelium Mobile structure Skeletal muscles and sensory receptors Red color due to blood vessels
Tongue Oral cavity, thick Lingual frenulumPapillaeLingual tonsils
Palate Roof of oral cavityHard and Soft UvulaPalatine tonsilsPharyngeal tonsils
TeethHardest structures in the bodyTypes (primary, etc.) Crown, enamels, root canalsHelp break down food into pieces
Salivary GlandsFunction:
Overall saliva begins chemical digestion of carbohydrates, cleans teeth and mouth, and binds food
Two types of secretory cells:Serous Cells- secrete salivary amylaseMucous Cells- secrete thick liquid
Salivary GlandsThree major glands:
Parotid Glands- Largest, secretes salivary amylase rich liquid
Submandibular Glands- Secretes a fluid that is equally serous and mucus
Sublingual Glands- Secretes a thick mucus fluid
Salivary GlandsTwo types of secretion Stimuli:
Sympathetic- impulses that secrete viscous saliva
Parasympathetic- secrete watery saliva, activated by sight, taste, smell, or thought of pleasant food
Swallowing 3 stages
Voluntary; food chewed and mixed with saliva; bolus.
Swallowing reflex at pharyngeal opening Peristalsis transports food from esophagus to
stomach
Pharynx and Esophagus Pharynx connects nasal and oral cavities with
larynx and esophagusNasopharynxOropharynxLaryngopharynxSwallowing stages Peristalsis
StomachHas three regions:
Cardiac region: small area near esophageal opening
Funic region: temporary storage areaPyloric region: narrows and becomes pyloric
canal Pyloric sphincter is the valve that control gastric
emptying
StomachGastric Glands:
Mucous cell- alkaline secretion that protects stomach wall
Parietal cells- (oxyntic cells) release hydrochloric acid Also secretes intrinsic factor needed for absorption
of vitamin B12Chief cells- (peptic cells) release digestive
enzymes
StomachReleases pepsinogen which becomes pepsin
from HClDigests most dietary proteins
All three cell secretions together create gastric juice
Gastric lipase is a weak secretion that breaks down fats
StomachRegulation:
Cholecystokinn (from intestine), intestinal somatostatin, urogastrone
Acetylcholine from nerve endings Parasympathetic impulses release gastrin
Both of these release histamine from mucous cells which stimulates gastric secretion
StomachGastric secretion occurs in three phases:
Cephalic- sight, taste, smell, or thought of food releases gastric secretions
Gastric- Food in stomach releases gastrinIntestinal- small intestine releases intestinal
gastrin which increases gastric juice secretion
StomachAbsorption:
Not very effective at absorbing water, some salts, lipid-soluble drugs, and alcohol
Mixing and Emptying:Chyme produced from mixingPeristalsis pushes it to pyloric sphincter which
causes it to relaxLength of time in stomach depends:
Liquids very rapid, fats long, proteins quick, carbohydrates very quick
LiverLocation/Background
AngiotensinogenThrombopoietinHepcidinBetatrophin
StructureFunctions
ProducesMetabolic ActivitiesStores
BileBackground
Contains
GallbladderLocation/BackgroundStructureFunctions
StorageBile salts
Chyme
PancreasLocationStructureSecretions
Pancreatic Juices Contains…
Enzymes Nuclei Amylase Lipase Trypsin Chymotrypsin Carboxytrypsin
They digest…
Small IntestineThe small intestine is about six meters long
and contributes to digestion, absorption, and transportation
Contains three parts:Duodenum- shortest part and is responsible for
most chemical digestion Contains a large amount of mucus secreting cells
and receives digestion aid from pancreas and liver
Small IntestineJejunum- Contains most of the absorption. Villi
and microvilli absorb what the body needsIleum- Primarily absorbs B12 and bile salts.
Also absorbs anything the jejunum missed
Small IntestineSecretions:
Secretin- in duodenumMotilin- also in duodenumPeptidase- breaks down peptides into amino acidsSucrase, maltase, lactase- break down
disaccharides into monosaccharidesIntestinal lipase- breaks down fatty acids and
glycerolEnterokinase- Shortens trypsinogen and trypsin
Regulation:Direct contact with chyme stimulates secretions,
parasympathetic reflexes trigger secretions as well
Small IntestineAbsorption:
Carbohydrates are absorbed by both facilitated diffusion and active transportation through villi
Proteins are broken down into amino acids and are absorbed into villi by active transportation
Small IntestineFat molecules are absorbed in several steps:
Fatty acid diffuses through villi Resynthesized into previously digested forms Encased in proteins Large molecules of lipoprotein called chylomicrions
go to lacteals of the villi Molecules are emptied into the lymphatic system
Small IntestineWater and electrolytes such as sodium and
potassium are absorbedMovement:
Peristalsis occurs along with segmentation Segmentation- ring like contractions that cut chyme
into segments and slow its movementsParasympathetic impulses enhance movement
and sympathetic impulses inhibit movement
Large IntestineContains several parts:
Cecum, colon, rectum, and anal canal Colon divided as well:
Ascending, transverse, descending, and sigmoid colons
Large IntestineFunction:
Very little digestionSecrete large amounts of mucus regulated by
chyme and parasympathetic impulsesAbsorption limited to water and certain ions
such as sodiumBacteria is prevalent and can aid in digestion
of certain substances
Large IntestineMovement:
Mainly relies on peristalsis but is much slower. Generally only two to three mass movements per day
Rectum:Feces enters the rectum which causes the
defecation reflex to occurPeristalsis movements increase, the glottis
closes and the diaphragm lowersThe external anal sphincter is signaled to relax
and feces is forced out
Works Cited www.meritnation.com www.studyblue.com www.pray40.com www.academic.amc.edu www.entertainment.howstuffworks.com http://www.dietdoctor.com/restoring-liver-function-lchf http://hepatitisctreatsment.blogspot.com/2014/11/liver-disease.html http://galleryhip.com/bile.html http://www.webmd.com/digestive-disorders/picture-of-the-gallbladder http://www.merriam-webster.com/dictionary/chyme http://www.uchospitals.edu/online-library/content=CDR62957 http://upload.wikimedia.org/wikipedia/commons/7/77/
Blausen_0817_SmallIntestine_Anatomy.png http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/G/
GutHormones.html https://www.boundless.com/physiology/textbooks/boundless-anatomy-and-
physiology-textbook/the-digestive-system-23/phases-of-digestion-226/hormones-of-the-digestive-system-1110-6772/