CHAPTER 14CHAPTER 14

DIGESTIVE SYSTEMDIGESTIVE SYSTEM

VOCABULARY WORDSVOCABULARY WORDSalimentary canal lesser omentumappendix lingual frenulumbile liver cecum lumenchyme masticatedduodenum pancreasesophagus phenylketonuria (PKU)gallbladder pyloric sphincter/valvegreater omentum rugaeileocecal valve small intestineileum stomachjejunum uvula

Large intestine

COLOR CODE – Plate 78COLOR CODE – Plate 78Oral cavity – Oral cavity – peachpeach liver - liver - redredPharynx – Pharynx – dark greendark green gall bladder – gall bladder – light greenlight greenEsophagus – Esophagus – brownbrown pancreas - pancreas - purplepurple Stomach – Stomach – magenta (dk. pink)magenta (dk. pink) spleen - spleen - tantanDuodenum – Duodenum – light bluelight blue submandibular - submandibular - yellowyellowJejunum – Jejunum – blueblue sublingual - sublingual - orangeorangeIleum – Ileum – dark bluedark blue parotid – parotid – light greenlight greenLarge intestine – Large intestine – orangeorangeAppendix – Appendix – pinkpinkRectum – Rectum – graygrayTongue – Tongue – redred

Color Code – Plate 79Color Code – Plate 79Frenulum – Frenulum – aquaaqua Gingiva (gum) – Gingiva (gum) – pinkpinkHard palate – Hard palate – dark bluedark blueSoft palate – Soft palate – light bluelight blueUvula – Uvula – purplepurpleOral pharynx – Oral pharynx – tantanPalatine tonsil – Palatine tonsil – greengreenTongue – Tongue – redredSublingual gland – Sublingual gland – orangeorangeSubmandibular gland – Submandibular gland – yellowyellowParotid gland – Parotid gland – light greenlight greenEpiglottis – Epiglottis – brownbrownLingual tonsils – Lingual tonsils – dark greendark green

Color Code – Plate 83Color Code – Plate 83Fundus – Fundus – dark bluedark blue submucosa - submucosa - pinkpinkBody – Body – blueblue oblique muscle - oblique muscle - brownbrownPylorus – Pylorus – light bluelight blue circular muscle – circular muscle – light brownlight brownPyloric sphincter – Pyloric sphincter – purplepurple longitudinal muscle - longitudinal muscle - tantan< curvature – < curvature – aquaaqua serosa - serosa - magentamagenta> Curvature – > Curvature – turquoiseturquoisediaphragm - diaphragm - graygrayRugae – Rugae – peachpeach esophagus - esophagus - yellowyellowSurface/mucous cells – Surface/mucous cells – dark greendark green duodenum - duodenum - redredParietal cells – Parietal cells – greengreenChief cells – Chief cells – light greenlight greenMuscular mucose - Muscular mucose - orangeorange

Color Code – Plate 87Color Code – Plate 87

Liver – Liver – redredGallbladder – Gallbladder – light greenlight greenPancreas – Pancreas – graygraySpleen – Spleen – tantanAbdominal aorta – Abdominal aorta – pinkpinkInferior vena cava - Inferior vena cava - magentamagenta

I. Anatomy of Digestive Sys.I. Anatomy of Digestive Sys.

A.A. 2 main groups of organs2 main groups of organs1. those forming the alimentary canal1. those forming the alimentary canal2. accessory digestive organs2. accessory digestive organs

B. Alimentary canalB. Alimentary canal1. performs all dig. Functions1. performs all dig. Functions2. functions: ingesting, digesting,2. functions: ingesting, digesting,

absorbing, defecationabsorbing, defecationC. Accessory digestive organsC. Accessory digestive organs

assist in the process of digestionassist in the process of digestion

II. ALIMENTARY CANALII. ALIMENTARY CANAL

A.A. Also called the GI tract Also called the GI tract (gastrointestinal)(gastrointestinal)

B.B. Approx. 9m / 30 ft. longApprox. 9m / 30 ft. longC.C. Shorter in a living person Shorter in a living person muscle muscle

tonetoneD.D. Mouth / Oral CavityMouth / Oral Cavity

1. masticated 1. masticated chewed chewed

2. break down of food b/g b/f food leaves2. break down of food b/g b/f food leaves mouthmouth

3. tongue – continually mixes food w/3. tongue – continually mixes food w/ saliva & initiates swallowingsaliva & initiates swallowing

4. lingual frenulum4. lingual frenuluma. fold of mucous membrane that a. fold of mucous membrane that

secures tongue to floor of mouthsecures tongue to floor of mouthb. limits posterior mmt. of tongueb. limits posterior mmt. of tonguec. if extremely short c. if extremely short “tongue-tied” “tongue-tied”

E. Pharynx E. Pharynx 1. common passageway for food, fluid, air1. common passageway for food, fluid, air2. has 3 sub2. has 3 sub÷÷

a. nasopharynx – part of respiratorya. nasopharynx – part of respiratory passagewaypassageway

b. oropharynx – posterior to oral cavityb. oropharynx – posterior to oral cavityc. laryngopharynx – continuous w/c. laryngopharynx – continuous w/

esophagusesophagus3. peristalsis3. peristalsis

a. propelling mech. for food froma. propelling mech. for food from pharynx i/t esophaguspharynx i/t esophagus

b. alternating contraction of 2 muscleb. alternating contraction of 2 muscle layerslayers

Picture A shows peristalsis

F. EsophagusF. Esophagus1. passageway for food to stomach1. passageway for food to stomach2. food conducted by peristalsis2. food conducted by peristalsis3. has 4 basic tissue layers 3. has 4 basic tissue layers tunics tunicsa. mucosaa. mucosa*inner most layer*inner most layer*lines cavity / lumen of esophagus*lines cavity / lumen of esophagus*epithelium is >ly simple columnar*epithelium is >ly simple columnarb. submucosab. submucosa*just b/n mucosa*just b/n mucosac. muscularis externac. muscularis externa*has 2 layers of smooth muscle: *has 2 layers of smooth muscle: inner circular layerinner circular layerouter longitudnal layerouter longitudnal layerd. serosad. serosa*outer most layer*outer most layer

G. StomachG. Stomach1. C-shaped; left side of abdominal cavity1. C-shaped; left side of abdominal cavity2. when full 2. when full approx. 4-L / 1-gal of food approx. 4-L / 1-gal of food3. covered by omentum3. covered by omentuma. > omentuma. > omentum* xtension of peritoneum* xtension of peritoneum* drapes downward & covers* drapes downward & covers

abdominal organs like a lacy abdominal organs like a lacy apron apronb. < omentumb. < omentum* double layer of peritoneum* double layer of peritoneum* covers from liver to <er curve* covers from liver to <er curve

4. has 3 muscle layers4. has 3 muscle layersa. longitudinala. longitudinalb. circularb. circularc. muscularis externa - obliquely arrangedc. muscularis externa - obliquely arranged

layerlayer5. where chemical break down of proteins b/g5. where chemical break down of proteins b/g6. produces 2-3 L of gastric juice / day6. produces 2-3 L of gastric juice / day

a. intrinsic factor – sub. needed for a. intrinsic factor – sub. needed for Vitamin B-12 absorptionVitamin B-12 absorption

b. chief cells – produce protein-digestingb. chief cells – produce protein-digesting enzymesenzymes

c. parietal cells – produce HCl (corrosive,c. parietal cells – produce HCl (corrosive, activates pepsinogen activates pepsinogen pepsin) pepsin)

7. chyme7. chyme a. sub. from food processeda. sub. from food processed b. resembles heavy creamb. resembles heavy cream c. enters small intestine thru pyloricc. enters small intestine thru pyloric

sphincter (3-6 hr. journey thru sm. int.)sphincter (3-6 hr. journey thru sm. int.)H. Small IntestineH. Small Intestine

1. mj. dig. organ1. mj. dig. organ2. where chemical dig. really begins2. where chemical dig. really begins3. where nearly all food absorption occurs i3. where nearly all food absorption occurs i4. longest part of alimentary canal – 4. longest part of alimentary canal –

length: 2length: 2½½ – 7m / 8 – 18 ft. – 7m / 8 – 18 ft.

5. has 3 subdivisions:5. has 3 subdivisions:a. duodenuma. duodenumb. jejunumb. jejunumc. ileumc. ileum6. extends from pyloric sphincter to6. extends from pyloric sphincter to ileocecal valveileocecal valvea. pyloric sphincter a. pyloric sphincter *controls food mmt. i/t sm. int.*controls food mmt. i/t sm. int.*prevents sm. int. from being*prevents sm. int. from being overwhelmed (“gatekeeper”)overwhelmed (“gatekeeper”)b. ileocecal valveb. ileocecal valve*where ileum joins lg. int.*where ileum joins lg. int.

I. Large IntestineI. Large Intestine1. larger in diameter, shorter in length than 1. larger in diameter, shorter in length than

sm. int.sm. int.2. passage of feces (undigested food 2. passage of feces (undigested food particles) to end of dig. tractparticles) to end of dig. tract3. has 5 sub3. has 5 sub÷÷

a. cecuma. cecumb. appendix – hangs from cecum & b. appendix – hangs from cecum &

collects bacteriacollects bacteriac. colonc. colond. rectumd. rectume. anal canale. anal canal

III. Accessory Digestive OrgansIII. Accessory Digestive Organs

A. Salivary GlandsA. Salivary Glands1. 3 pr. that empty secretions i/t mouth1. 3 pr. that empty secretions i/t moutha. parotid glandsa. parotid glands*larger*larger*inflammation *inflammation mumps mumpsb. submandibular glandsb. submandibular glandsjust inferior to midmandiblejust inferior to midmandiblec. sublingual glandsc. sublingual glandsdeep & inferior to floor of mouthdeep & inferior to floor of mouth

2. saliva2. saliva*prod. of salivary glands*prod. of salivary glands*mixture of mucous & serous *mixture of mucous & serous

fluidfluid*contains enzyme amylase wh/ *contains enzyme amylase wh/

b/g b/g process of starch digestion process of starch digestionB. teethB. teeth

1. for mastication1. for mastication2. have 2 sets:2. have 2 sets:

*deciduous/baby teeth (20 teeth)*deciduous/baby teeth (20 teeth)*permanent teeth (32 teeth)*permanent teeth (32 teeth)

C. PancreasC. Pancreas1. extends across abdomen from spleen to 1. extends across abdomen from spleen to duodenumduodenum2. produces enzymes to break down all categories 2. produces enzymes to break down all categories of digestible foodsof digestible foods3. enzymes are secreted i/t duodenum3. enzymes are secreted i/t duodenum4. enzymes neutralize acidic chyme from stomach4. enzymes neutralize acidic chyme from stomach5. pancreatic juice contains enzymes:5. pancreatic juice contains enzymes:a. amylase – starch dig.a. amylase – starch dig.b. trypsin – protein dig.b. trypsin – protein dig.c. lipase – lipid dig.c. lipase – lipid dig.d. nuclease – nucleic acid dig.d. nuclease – nucleic acid dig.D. LiverD. Liver1. largest gland in body1. largest gland in body2. has 4 lobes wh/ a/m completely cover stomach2. has 4 lobes wh/ a/m completely cover stomach

3. digestive function 3. digestive function produce bile produce bile4. other functions:4. other functions:

a. ATP productiona. ATP productionb. degrades hormonesb. degrades hormonesc. detoxify drugs/alcoholc. detoxify drugs/alcohold. make cholesterold. make cholesterol

(has > 500 functions in body)(has > 500 functions in body)5. Bile5. Bile

a. yellow-green, Ha. yellow-green, H22O-y solutionO-y solutionb. contains: bile salts, bile pigments, b. contains: bile salts, bile pigments, cholesterol, phospholipids, cholesterol, phospholipids,

electrolyteselectrolytesc. emulsifies fats (breaks lg. globules i/t c. emulsifies fats (breaks lg. globules i/t sm.r ones sm.r ones

E. GallbladderE. Gallbladder1. sm. green sac snuggled i/t a fossa of1. sm. green sac snuggled i/t a fossa of inferior surface of liverinferior surface of liver2. stores bile when digestion is not 2. stores bile when digestion is not occurringoccurring3. gallstones3. gallstonesa. occurs when bile is stored for too a. occurs when bile is stored for too long long in the gallbladder or whenin the gallbladder or when too much Htoo much H22O is removed from O is removed from bile bileb. cholesterol crystallizes forming b. cholesterol crystallizes forming sharp stones sharp stones gallstones gallstones

IV. Digestive Diseases/conditionsIV. Digestive Diseases/conditionsA.A. JaundiceJaundice

1. occurs when blockage prevents bile from 1. occurs when blockage prevents bile from entering sm. int./ actual liver prob.s entering sm. int./ actual liver prob.s

2. bile accumulates & backs up i/t the liver & 2. bile accumulates & backs up i/t the liver & b/g to enter bloodstream b/g to enter bloodstream

3. pigments circulate t/o the body 3. pigments circulate t/o the body tissues tissues to b/c yellow to b/c yellow jaundiced jaundiced

B. HepatitisB. Hepatitis1. inflammation of the liver1. inflammation of the liver2. > often due to viral inf. 2. > often due to viral inf. contaminated contaminated HH22O or needlesO or needles

C. CirrhosisC. Cirrhosis1. chronic inflammatory cond. of liver1. chronic inflammatory cond. of liver2. liver is severely damaged & b/c hard & 2. liver is severely damaged & b/c hard & fibrous fibrous3. al/m guaranteed when drinking alcohol 3. al/m guaranteed when drinking alcohol for many years for many years4. a/s a consequence of hepatitis4. a/s a consequence of hepatitis

D. Phenylketonuria (PKU)D. Phenylketonuria (PKU)1. inability to digest/use protein 1. inability to digest/use protein

(specifically the amino acid phenylalanine)(specifically the amino acid phenylalanine)2. special diet is needed 2. special diet is needed brain damage brain damage

& & MR occurs MR occurs