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/