2. 1 The Digestive System

3. 2 Parts of the Alimentary Canal The Digestive System Consists of the alimentary canal and several accessory organs. Parts of the Alimentary Canal mouth Pharynx البلعوم Esophagus المرئ Stomach المعدة anal canal large intestine الامعاء الغليظة small intestine الامعاء الدقيقة

4. 3 The Alimentary Canal A tube that extends from the mouth to the anus Consists of four layers: -outer layer (protects) الطبقة الخارجية للحماية -second layer (muscular; contracts تنقبض and expands in wavelike motions called peristalsis) -third layer (vessels, nerves and glands that nourish and carry away waste). -innermost layer الطبقة الداخلية (mucous membrane غشاء مخاطي that secretes mucus and digestive enzymes) الانزيمات الهاضمة

5. 4 Organs of the Digestive System Parotid salivary gland Pharynx Esophagus Stomach Pancreas Small intestine Rectum المستقيم Anal canal Large intestine Duodenum Gall bladder Liver الكبد Submandibular salivary gland Sublingual salivary gland Tooth Tongue Mouth

6. 5 Tracing Toast mouthpharynx epiglottis esophagus stomach duodenum jejunum ileum cecum ascending colon transverse colon descending colon sigmoid colon rectum anus feces food Tracing food through the alimentary canal

7. 6 Mouth The lips الشفاه protect the mouth from receiving food that is too hot or too rough on the surface. The mouth is also called the oral cavity Food is taken into the mouth and chewed يمضغ with the assistance of the cheek muscles عضلات الوجه lips

8. 7 The Tongue Small raised areas called papillae are located on the tongue and they contain taste buds براعم التذوق The frenulum connects the tongue to the floor of the mouth. Process of chewing is called mastication المضغ The tongue moves the food around to prepare it for deglutition (swallowing) البلع Tongue اللسان.....

9. 8 Mouth Functions –mechanical digestion teeth –break up food –chemical digestion (saliva اللعاب ) amylase enzyme –digests starch mucus –protects soft lining of digestive system –lubricates food for easier swallowing buffers –neutralizes acid to prevent tooth decay anti-bacterial chemicals –kill bacteria that enter mouth with food

10. 9 Salivary Glands الغدد اللعابية parotid submandibular sublingual Submandibular gland Parotid gland Tongue Tooth Sublingual gland The function of the salivary glands The function of the salivary glands is to make saliva and help the bolus (soft mass of chewed food) go down the esophagus easily. Saliva contains enzymes which help break down food to a form which the body can use.

11. 10 Pharynx Muscular tube about 5 inches long in adults Also known as the throat Transmits food into the esophagus The epiglottis (a flap of tissue) covers the trachea القصبة الهوائية to prevent food from entering the larynx الحنجرة during swallowing which causes choking الاختناق.

12. 11 Esophagus Muscular tube about 9 to10 inches long in the adult that contracts rhythmically (peristalsis) to propel تدفع food toward the stomach Contains a group of muscles called the lower esophageal sphincter that closes off the entrance to the stomach to prevent reflux عودة of food, emesis or regurgitation (vomiting). Esophagus