The Digestive System

1. The Digestive System The Digestive System

2. small intestine الامعاء الدقيقة الفمmouth Pharynx البلعوم large intestine الامعاء الغليظة Esophagus المرئ anal canal القناة الشرجية Stomach المعدة Structure and Functionالتركيب والوظيفة The Digestive System Consists of the alimentary canal القناة الهضمية and several accessory organs عدد من الأعضاء المساعدة . Parts of the Alimentary Canal

3. The Alimentary Canal Structure and Function The Alimentary Canal • A tube أنبوبةthat extends تمتدfrom the mouth to the anus • Consists of four layers 4 طبقات: • -outer layer (protects)الطبقة الخارجية للحماية • -second layer (muscularالعضلية ; contracts تنقبضand expands in wavelike motions called peristalsis حركة تموجيه لدفع الغذاء) • -third layer (vessels اوعية, nerves and glands that nourish تغذيand carry away waste تطرد الفضلات ). • -innermost layerالطبقة الداخلية (mucous membrane غشاء مخاطيthat secretes mucus المخاط and digestive enzymes) الانزيمات الهاضمة

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

5. Tracing Toast food epiglottis mouth pharynx esophagus stomach anus feces duodenum rectum jejunum sigmoid colon ileum cecum transverse colon ascending colon descending colon Structure and Function Tracing food through the alimentary canal

6. Mouth Structure and Function Mouth lips The lipsالشفاه 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

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

8. Mouth • Functions • mechanical digestion • teeth • break up food • chemical digestion (salivaاللعاب ) • 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

9. Salivary Glands Structure and Function Salivary Glands الغدد اللعابية • parotid • submandibular • sublingual Tongue Tooth Parotid gland Submandibular gland Sublingual gland 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.

10. Pharynx Structure and Function 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 .

11. Esophagus Structure and Function 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).