Understanding the Digestive System: Structure & Function

1. 2.07 Remember the structures of the digestive system

2. Essential Question What are the structures of the digestive system? 2.07 Remember the structures of the digestive system

3. Structures of the digestive system Digestive system Also known as: Alimentary Canal Digestive Tract Gastrointestinal Tract Upper GI Lower GI Approximately 30 FEET in length from mouth to anus 2.07 Remember the structures of the digestive system

4. Structures of the digestive system Primary structures Mouth Esophagus Stomach Small intestines Large intestines Accessory (assistive) structures Tongue Teeth Salivary glands Pancreas Liver Gall bladder 2.07 Remember the structures of the digestive system

5. Structures of the digestive system Mouth (buccal cavity) Tongue Teeth Salivary Glands Palate Uvula 2.07 Remember the structures of the digestive system

6. Structures of the digestive system Tongue Attached to floor of mouth Made of skeletal muscle attached to four bones Taste buds (Papillae) on the surface Sweet ,Sour Bitter, Salty Also sensitive to Cold, heat and pressure 2.07 Remember the structures of the digestive system

7. Structures of the digestive system Teeth Primary (deciduous) 20 “baby teeth” (6 mos-2 yrs) Secondary (permanent) 32 “adult teeth”, (6 YRS) Wisdom teeth (3rd molars) usually appear between 17-25 yrs. old Did you know??? Canine teeth are also known as cuspids and eye teeth. 2.07 Remember the structures of the digestive system

8. Types of Teeth • Incisors- sharp edges for BITING • Canines- pointed for TEARING • Molars- ridges for CRUSHING & GRINDING • Wisdom teeth

9. Structures of the digestive system Salivary glands Parotid gland- Largest salivary gland, found on both side of the face, in front and below the ears. Secretes salivary amylase Submandibular gland-approx. size of a walnut, secretes mucin & ptyalin salivary amylase Sublingual gland- smallest of the 3, found under the sides of the tongue, secretes mainly mucus

10. Structures of the digestive system Palate Hard- roof of mouth Soft- back of hard palate Uvula Flap of skin hanging in the middle of soft palate. Prevents food from entering nasal cavity when swallowing

11. Structures of the digestive system Pharynx (throat) Nasopharynx Oropharynx Hypopharynx 2.07 Remember the structures of the digestive system

12. Structures of the digestive system Esophagus Muscular tube, 10” long Connects the pharynx and stomach Esophageal wall layers Mucosa Submucosa Muscular External serous 2.07 Remember the structures of the digestive system

13. Structures of the digestive system Stomach Upper left quadrant of the of the abdominal cavity, 3 areas: Fundus Body Pylorus Cardiac Sphincter- @ EG junction Pyloric Sphincter- @ pyloris /duodenum Rugae- folds of tissue (like an accordian) (increases surface area)

14. Structures of the digestive system Smallintestines Duodenum First segment 12” long Jejunum Second segment 8’ long Ileum Third segment 10-12’ long

15. Structures of the digestive system Accessories… Pancreas Secretes digestive enzymes Located behind stomach Liver Largest organ of body Connects to gall bladder and small intestine by ducts Gall Bladder Stores and concentrates bile until needed by body

16. Structures of the digestive system Large intestines (Colon) Approximately 2” in diameter 5’ long 3 SECTIONS: ASCENDING (Hepatic Flexure) TRANSVERSE (Splenic Flexure) DESCENDING/SIGMOID Anus / Rectum Secretes large amounts of mucus to lubricate waste products for defecation

17. Structures of the digestive system Checkyourknowledge… 2.07 Remember the structures of the digestive system

18. Essential Question What are the structures of the digestive system? 2.07 Remember the structures of the digestive system