1. The Digestive System Human Anatomy and Physiology Per 2 & 3 Miss Tavitian

2. Main functions - Ingest food - Break down food small enough to cross cell membrane - Absorb nutrients - Eliminate what cannot be digested

3. Digestion begins when you begin to salivate Long hours of school“taking notes”

4. Alimentary Canal = tubular passage starting with mouth and ending with anus

5. Mouth Teeth Mechanically break down food Saliva chemically break down food Salivary amylase digestion of starch to maltose https://www.youtube.com/watch?v=DKeEbVL ZNWc https://www.youtube.com/watch?v=4Ed57ZCo Xjg

6. Chewed Food + Saliva = bolus Tongue pushes food toward the soft palate which triggers a swallowing reflex

7. Salivary Glands produce saliva which travels through ducts

8. Medical Conditions Parotid Tumor Swollen Submandibular gland

9. Pharynx = common passageway for food & air soft palate pulled up to block nasopharynx Tongue also prevents food from coming back to oral cavity During swallowing:

10. During swallowing, the Larynx is pulled up and the Epiglottis closes off the glottis

11. When Food Does Go Down The Wrong Pipe it can lead to major problems Pulmonary Aspiration Pulmonary – relating to lungs Aspiration – breathing in a foreign object

12. Problems associated with food going down the wrong pipe Aspiration Pneumonia -Pneumonia- infection or swelling of lungs -Aspiration pneumonia can be caused by inhalation of food or drink, vomit, oil, bacterial ingestion Choking – airway is obstructed by object

13. Once the bolus enters the Esophagus, it makes its way to the stomach through peristalsis

14. Once the food enters the Stomach, the esophageal sphincter will close to ensure food stays in stomach (2-3seconds)

15. When The Esophageal sphincter fails to close completely, and gastric acids come up the esophagus, Acid Reflux occurs

16. “Heartburn” -“Heartburn” is the symptom associated with the stomach acid traveling up the esophagus - The esophagus is posterior to the heart

17. Upon entry into the stomach -Three important jobs of the stomach: > store food > break down food into liquefied mixture > slowly empty food into small intestine *nutrients do not get absorbed in stomach

18. In the Stomach Chief Cells produce pepsinogen and chymosin > protein digestion begins in stomach Parietal Cells produce - >Hydrochloric Acid (HCl) >Intrinsic Factor binds to B12 so it doesn’t get broken down Pylorus associated with pyloric sphincter & hold food until ready to be passed on Food will stay in stomach for 6-8 hours

19. A Couple more cells of the stomach -Chief Cells -Parietal Cells -Mucous Cells  Secrete mucous to protect epithelium from HCl acid - G Cells  secrete Gastrin hormone which helps stimulate HCl https://www.youtube.com/watch?v=mw8ptO3T y6A

20. Mucous protects stomach from HCl,

21. Peptic Ulcer -> Barium X-ray highlights organs

22. Parts of Stomach Cardiac Region  part of the stomach closest to the heart Fundic Region  holds food temporarily Body of stomach  main part of stomach Pyloric region  leads to pylorus which empties into small intestine

23. Stomach Layers of Stomach Rugae- folds of the stomach

24. Overview of Stomach

25. Gastric Bypass Surgery https://www.youtube.com/watch?v=WN6pECa L3Fw https://www.youtube.com/watch?v=X0ObD- 6aRlI

26. Upon Leaving the Stomach food + gastric juices (chyme) travels through pylorus to small intestine

27. Parts of small intestine Three Parts to the small intestine: -Duodenum -Jejunum -Ileum

28. What Happens in the small intestine? Ducts from Liver, Gallbladder, and Pancreas join to form one duct that enters Duodenum Proteins, Lipids, and Carbohydrates will finish undergoing digestion

29. Food will pass from small intestine to large intestine through Ileocecal valve

30. Large Intestine

31. Parts of Colon (aka Large Intestine) Large Intestine has four parts: -Ascending Colon -Transverse Colon -Descending Colon -Sigmoid Colon

32. Haustra- pouches in large intestine that expand to store material https://www.youtube.com/watch?v=Ujr0UAby PS4

33. Taenia coli- Muscle along the surface that help with peristalsis (green arrow)