Digestive System




Google Slides: http://bit.ly/15digest | Notes on Google Docs

Essential Questions:

1. How do animals (and humans) obtain nutrients?
2.  What happens when animals don’t get proper nutrients?
3.  How is waste eliminated from the body?
4.  What disorders can affect the working of the digestive system?

What is scurvy? Disease caused by a lack of  ___________________
                             Body can no longer produce ____________________
                              Symptoms: ________________________________________________________ _

What is the function of the digestive system?

Function:   _________________________________________
Consists of: ________________________________________

Characteristics of the Alimentary Canal

1. Mucosa   ____________________________________
2.  Submucosa  _________________________________
3.  Muscular  ____________________________________
4.  Serosa  ______________________________________

In the small intestine, villa serve what purpose?

Draw the layers of the alimentary canal:




Mixing Movements  -  __________________________________
Propelling Movements - _________________________________


Anatomy of the Mouth

Mouth – begins digestion by chewing and mixing with saliva
Tongue – moves food during chewing, connects to the floor of the mouth via the ________________________, contains papillae

Palate – forms roof of oral cavity (hard and soft); ________________ at back of the mouth
Palatine tonsils – back of the mouth/throat, organs that protect against infection. What is tonsillitis? _______________________
What are tonsil stones?  _________________________________



Teeth – primary vs. secondary teeth;         

Label: incisors, cuspids, bicuspids (premolars), molars

Anatomy of a Tooth     Label by number
_____Crown – projects above the gums
_____Root – anchored to the alveolar process of the jaw
_____Enamel – made of calcium salts, hardest substance in body _____Dentin – similar to bone, surrounds tooth’s central cavity
_____Root Canal - blood vessels and nerves

What is a root canal? ________________________________

What are wisdom teeth? _______________________________

Why do they often need to be removed? _______________________________________


tooth anatomy


Salivary Glands

Amylase - ___________________________________

Label the glands on the drawing:

1) __________________________________________
2) _________________________________________
3) _________________________________________


Pharynx and Esophagus

3 sections of the Pharynx

Esophagus – moves food to the stomach

Esophageal ________________ - where it penetrates the diaphragm

_________________________  - entrance to the stomach




Four regions of the stomach

1. _________________________(esophageal opening, cardiac sphincter)
2 _________________________ (part that sticks up above the esophagus)
3. _________________________ (greater and lesser curvature)
4. _________________________(pyloric sphincter, controls emptying of the stomach into the sm. intestine)

Stomach Lining: ____________________________ prevents stomach from digesting itself

Glands secrete gastric juices for breakdown of food
_________________________________ - most important digestive enzyme for breaking down food
________________________ – paste of food molecules after its been broken down ; it is released from the pyloric sphincter valve into the first portion of the small intestine – duodenum

________________________ – folds within the stomach, increase surface area



Secretes insulin - breakdown of _______________________ | Pancreatic juice – breaks down ___________

Both empty into the _______________________________ 


Liver - has large right and small left lobe

biliary system

BILIARY SYSTEM – functions to create_____________ used in digestion; liver, gallbladder and ducts

The cystic duct comes from the ________________ | hepatic duct comes from the ____________________

Both ducts join to form the ________________________ which empties into the __________________

Liver Functions: maintains blood glucose, breakdown of lipids and fats, protein metabolism, stores iron and vitamins, destroys damaged red blood cells, removes toxic substances, secretes bile

Bile – yellowish-green liquid aids in digestion, breakdown of fat
What is jaundice? _____________________________________________________________


Small Intestine

 *Main function is the _______________________ of nutrients.

1. __________________________ - first part of the small intestine

2. __________________________ – second part, ~2.2 m

3. __________________________– third part, longest ~3.3 m *jejunum and ileum are continuous

_______________________ – supports the coils of the small intestine, contains blood vessels to carry nutrients

Greater ______________________ – (peritoneum) curtain-like membrane that drapes over parts of the system    

Intestinal Villi – increase surface area for ____________________________

Large Intestine

large intestine

1. ________________ – start of the large intestine, attached appendix

2. ___________________ –

ascending / transverse / descending / sigmoid

3. ________________– stores waste before it is expelled from the body

4. _________________ -muscular sphincter which controls the exit of waste

Functions –reabsorbs water and passes along material that was not digested; contains intestinal flora (bacteria to break down cellulose)

What is its main job? ________________________________

Mass movements – large portions of the colon contract to move material through it, usually after eating (defecation)

What is the Bristol Stool Chart? _________________________________________________________


Disorders of the Digestive System

What doctor treats disorders of the digestive system?  ________________________________

1. GERD / Heartburn
2. Diarrhea or Dysentery ( c. diff)
3. Cholera
4.  C. diff and the microbiome
5.  Hepatitis (A, B, C)
6. Crohn’s Disease / Irritable Bowel Syndrome
7. Stomach Ulcers
8.  Constipation
9. Hemorrhoids
10. Lactose Intolerance 

11.  Celiac disease (gluten sensitivity)
12. Appendicitis
13. Hernia
14. Gallstones
15. Malnutrition (scurvy, rickets)
16. Obesity / Gastric Bypass
17. Colon Cancer / Colonoscopy