Ch 15 the Digestive System

7/29/2019 Ch 15 the Digestive System

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The Digestive System

Chapter 15



15.1

Functions: mechanical andchemical breakdown of food

*absorption of nutrients

Consists of alimentary canal

and accessory organs



Wall of the Alimentary Canal



15.2 Characteristics of the Canal

1. Mucosa - protects tissues and carries absorption

2. Submucosa - glands, blood vessels, nerves

3. Muscular Layer - smooth muscle tissue, circular &longitudinal fibers, pushes food (PERISTALSIS)

4. Serosa (serous layer) - visceral perioneum, outer covering

of the tube, lubricates surfaces (serous fluid)





Mixing Movements

Contractions mix food with digestive juices

Peristalsis - pushes food down the tube



Anatomy of the Mouth



Anatomy of a Tooth



Teeth

Incisors

Cuspid (canine)

Bicuspids

Molars







Tooth Decay



METHMOUTH





ROOT CANAL

http://www.youtube.com/watch?v=412Bv2JN42U



Salivary GlandsParotid - ear, cheekSubmandibular - below jawSublingual - under tongue



Pharynx

nasopharynx

oropharynx

laryngopharynx



Esophagus

esophageal hiatus iswhere it penetrates thediaphragm cardiac sphincter at

entrance to stomach





Stomach

Regions

● Cardiac● Fundic● Body (greater and

lesser curvature)● Pyloric



Stomach Lining

Gastric Juices contain acids that break down

food - secreted by gastric glands

PEPSIN - most important digestive enzyme for

breaking down food

Mucus prevents stomachfrom digesting itself



Chyme - paste, after food has been brokendown, released then into the duodenum via the

pyloric sphincter valve

Rugae - folds withinstomach

Gastric Pits containglands to make

juices



PANCREAS - secretes insulin whichbreaks down sugars

Pancreatic Juice also breaks down fat



Liver

1 large right lobe | 1 smaller left lobe



Liver - ducts and vessels

Hepatic duct --> to common bile duct

Hepatic portal vein - circulates blood throughoutliver



Liver Functions

1. blood glucose levels

2. breakdown of lipids and fats3. protein metabolism4. stores vitamins5. destroys damaged RBCs

6. removes toxins7. secretes bile



Remember Bili Lights?

Using bili lights is a therapeutic procedure performed on newborn or premature infants to reduce elevated levels of bilirubin. If blood levelsof bilirubin become too high, the bilirubin begins to dissolve in the body

tissues, producing the characteristic yellow eyes and skin of jaundice.



Gall Bladder - under liver cystic duct --> common bile duct

stores bile, digests fat*gallstones may form

S ll I i



Small Intestine

Starts at the pyloric

sphincter

1. Duodenum

2. Jejunum

3. Ileum



Greater Omentum

a "curtain-like" membrane that covers theintestines, stores fat and lays like a drape



Greater Omentum



http://www.youtube.com/watch?v=2bmfH5yQHak



Intestinal villi - increase surface area toabsorb nutrients, connect to vessels



The main functionof the smallintestine is to

secrete chemicalsthat break downfood and carry thenutrients away inthe bloodstream. In oneword:

ABSORPTION

L I t ti



Large Intestine

Cecum

Appendix

Colon (4 parts)

Cecum

Ascending

F ti f L I t ti

http://www.youtube.com/watch?v=PpzfKt-47iA



Function of Large Intestine

Secretes mucus, reabsorbs water, contains bacteria to aid indigestion (intestinal flor a)

Mass Movements (defecation) - removes undigested food

The main job is

WATERREABSORPTION...








How to Make Fake Poop...

http://www.youtube.com/watch?v=nfvtkXCojL0



LABEL THIS!

http://www.youtube.com/watch?v=dFdRqoVSZPE



LABEL THIS!





1. esophagus2. liver 3. stomach4. pyloric sphincter 5. duodenum6. pancreas

7. jejunum8. ileum9. cecum10. appendix11. ascending colon

12. descending colon13. sigmoid colong14. anus



Nutrition

Di d f th Di ti S t



Disorders of the Digestive System

GERD

Gastroesophageal

reflux disease



Dysentery or Diarrhea

HEPATITIS A B C



HEPATITIS A, B, C

Hepatitis A

http://www.youtube.com/watch?v=y6osMO5xnag



Hepatitis A

is caused by eating food and drinking water infected with a viruscalled HAV. While it can cause swelling and inflammation in the

liver, it doesn't lead to chronic disease. Almost everyone who getshepatitis A has a full recovery, some may need hospitalization

Many people are recommended to receive hepatitis A vaccine,including people at increased risk for exposure to hepatitis A virusinfection and people who are more likely to get seriously ill if infected

with the virus



http://www.youtube.com/watch?v=Te-rDGG4azc











Hepatitis B is caused by the virus HBV. It is spread by contactwith an infected person's blood, semen, or other body fluid.

And, it is a sexually transmitted disease (STD).

Some people never develop symptoms, others develop chronicsymptoms that stay with them their whole life.

H titi C i d b th i HCV It i d th



Hepatitis C is caused by the virus HCV. It is spread the sameway as hepatitis B, through contact with an infected person'sblood, semen, or body fluid (see above).

Like hepatitis B, hepatitis C causes swelling of the liver andcan cause liver damage that can lead to cancer. Most peoplewho have hepatitis C develop a chronic infection. This maylead to a scarring of the liver, called cirrhosis.

Blood banks test alldonated blood for hepatitis C, greatlyreducing the risk for getting the virus fromblood transfusions or blood products.

http://alcoholism.about.com/library/blcirrhosis.htm



IBS I it bl B l S d



IBS - Irritable Bowel Syndrome

STOMACH ULCERS



STOMACH ULCERS



LactoseIntolerance

Inability to digestmilk, can causestomach upset

Appendicitis



Appendicitis

H i



Hernia

intestinespoke throughabdominalmuscles



When people with celiac



When people with celiacdisease eat foods or useproducts containing gluten,

their immune system respondsby damaging or destroying villi

Without healthy villi, a person

becomes malnourished, nomatter how much food oneeats.

Gallstones (Cholelithiasis)



( )

Gallstones are made from cholesterol and other

things found in the bile. They can be smaller than agrain of sand or as large as a golf ball.

G t i B S

http://www.webmd.com/hw-popup/cholesterol

http://www.webmd.com/hw-popup/gallstones



Gastric Bypass Surgery

http://www.hurtbyadoctor.com/Gastric-Bypass-Surgery-Malpractice-Lawsuits-Information-

Home.htm

C l C

http://www.hurtbyadoctor.com/Gastric-Bypass-Surgery-Malpractice-Lawsuits-Information-Home.htm







Colon Cancer

Colonoscopy is a screening technique to detect cancer.

See Katie Couric's Colonoscopy

http://www.youtube.com/watch?v=15JsYSZIT-Q

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Ch 15 the Digestive System