الهضم إلى المعدة 81ص PDF

سلايد الجهاز الهضمي بالأندومي كتابة فقط The human digestive system: There are several organs and other components involved in the digestion of food. The organs known as the accessory digestive glands are the liver, gall bladder and pancreas. Other components include the mouth, salivary glands, ton...

سلايد الجهاز الهضمي بالأندومي كتابة فقط The human digestive system: There are several organs and other components involved in the digestion of food. The organs known as the accessory digestive glands are the liver, gall bladder and pancreas. Other components include the mouth, salivary glands, tongue, teeth and epiglottis. The largest structure of the digestive system is the gastrointestinal tract (GI tract). This starts at the mouth and ends at the anus, covering a distance of about nine (9) metres Components of the Digestive System I- Oral Cavity II- Pharynx III- Esophagus IV- Stomach V- Small intestine VI- Large intestine VII- Liver VIII- Gallbladder IX- Pancreas X- Spleen XI- Peritoneum I- Oral Cavity: Is a space located between the lips and cheeks on the external surface to the palatoglossal fold on the internal surface. The oral cavity is importent in mastication, tasting and talking. palatoglossal fold on the internal surface. Divisions of the oral cavity: -Vestibul: The area between the teeth and lips or cheek -Oral cavity proper: The area located internal to the teeth Posteriorly, the oral cavity is continuos with the oropharynx. -The tongue is a major structure located on the oral cavity floor. All the salivary glands drain into the oral cavity. *lymph nodes *sublingual gland *submandibular gland *parotid gland The parotid duct drains into the oral cavity at the parotid papilla, located along the mucous membrane of the cheek opposite the 2nd maxillary molar. It emerges from the gland and runs forward along the lateral side of the masseter muscle. It takes a steep turn at the border of the masseter and passes through the buccinator muscle, opening into the vestibule of the mouth. In this course, the duct is surrounded by the buccal fat pad. Buccal fat is one of several encapsulated fat masses in the cheek. Boundary of the Oral Cavity -Superior, The roof is hard palate -Posterosuperior, Soft palate -Lateral, Cheeks -Inferior, The floor of the oral cavity (which is located along the lingual border of the mandible, forming a horseshoe-shaped region) The superior border (or roof) of the oral cavity is the hard palate, comprising the anterior 2/3 of the entire palate Separates the oral cavity from the nasal cavity The bones of the hard palate are covered by a thick mucous membrane, known as masticatory mucosa (keratinized stratified squamous epithelium) Moving posteriorly from the incisive papilla, the mucous membrane has a thick midline palatal raphe. Lateral transverse ridges called transverse rugae (plicae) are located along the mucous membrane of the hard palate. Posteriosuperior Border: Soft Palate The posterosuperior border of the oral cavity is the soft palate. The soft palate is the continuation of the palate posteriorly and makes up approximately 1/3 of the entire palate. The soft palate has 3 margins: Anteriorly, it is continuous with the hard palate at the vibrating line. Posterolaterally, it forms the superior portion of the palatoglossal and palatopharyngeal folds. Posteriorly the uvula hangs in the center of the posterior free margin. The thick palatine aponeurosis forms the foundation of the soft palate. The soft palate helps close off the nasopharynx during deglutition forming a seal at the fold of Passavant. (Passavant's pad or palatopharyngeal ridge). The soft palate is composed of 5 muscles : Musculus uvulae Tensor veli palatini Levator veli palatini Palatopharyngeus Palatoglossus (sometimes considered in the grouping of tongue muscles) The inferior border is the floor of the oral cavity: It is located along the lingual border of the mandible forming a horseshoe-shaped region The mylohyoid m. serves as the sling of the floor of the oral cavity and structures superior to it are the major contents. The largest structure is the tongue and related musculature. Tongue Largest structure in the floor. Lingual frenulum, A midline fold of tissue located at the base of the tongue and extends along the inferior surface of the tongue. Sublingual papilla: A swelling located on both sides of the lingual frenulum at the base of the tongue. Continuous with the sublingual folds overlying the sublingual glands on the floor of the oral cavity, marks the entrance of the saliva from the submandibular glands into the oral cavity. Submandibular duct: Lies along the sublingual gland under the mucosa. Plica fimbriata: Fimbriated folds located lateral to the lingual frenulum. Teeth are hard structures attached to the jaws and involved primarily in eating. Two arches contain the teeth: Maxillary arch, Mandibular arch. Humans have 2 sets of teeth during a lifetime: Deciduous teeth—the primary dentition Permanent teeth—the secondary dentition Between the ages of 6 and 12 years, there is a mixed dentition, in which both primary and permanent teeth are present in the oral cavity at the same time. DECIDUOUS TEETH There are 20 total deciduous teeth: 2 incisors, 1 canine, and 2 molars in each of the 4 quadrants of the oral cavity PERMANENT TEETH: There are 32 total permanent teeth: 2 incisors, 1 canine, 2 premolars, and 3 molars in each of the 4 quadrants of the oral cavity. The 1st permanent tooth to erupt into the oral cavity normally is the mandibular1st molar This eruption occurs at about 6 years of age It erupts distal to the primary dentition Labial: The surface of the anterior teeth that is closest to the lip Buccal: The surface of the posterior teeth that is closest to the cheek Facial: Used as a synonym for labial or buccal Lingual:Opposite the tongue in the mandibular arch and opposite the hard palate of the maxillary arch Mesial: Closest to the midline of the dental arch Distal: Farthest from the midline of the dental arch Occlusal: Used for chewing in posterior teeth Incisal: The cutting edge of anterior teeth Crown Anatomic crown : the portion of the tooth that has a surface of enamel. Root Anatomic root : the portion of the tooth that has a surface of cementum. Pharynx : 5-inch muscular tube from base of the skull to the lower border of the cricoid cartilage (C6), where it is continuous with the esophagus the pharyngeal plexus of veins. Responsible for properly conducting food to the esophagus and air to the lungs. Lies posterior to the nasal and oral cavities and the larynx and thus is divided into 3 parts: -Nasopharynx -Oropharynx -Laryngopharynx The pharyngeal muscles contract pushing the food into the esophagus, determining the shape of its lumen, and affecting its sound properties as the primary resonating cavity. There are two muscular layers of the pharynx: the outer circular layer and the inner longitudinal layer. The outer circular layer includes: 1-Inferior constrictor muscle 2-Middle constrictor muscle 3-Superior constrictor muscle The inner longitudinal layer includes: 1-Stylopharyngeus muscle 2-Salpingopharyngeus muscle 3-Palatopharyngeus muscle *The stylopharyngeus is a muscle in the head that stretches between the temporal styloid process and the pharynx. *The salpingopharyngeus muscle arises from the superior border of the medial cartilage of the pharyngotympanic tube (Eustachian tube), blends with the posterior fasciculus of the palatopharyngeus muscle. *The palatopharyngeus (palatopharyngeal) muscle is a small muscle in the roof of the mouth. Nasopharynx: The upper portion of the pharynx, the nasopharynx, extends from the base of the skull to the upper surface of the soft palate. It includes the space between the internal nares and the soft palate and lies above the oral cavity. The adenoids, also known as the pharyngeal tonsils, are lymphoid tissue structures located in the posterior wall of the nasopharynx. Waldeyer's tonsillar ring is an annular arrangement of lymphoid tissue in both the nasopharynx and oropharynx. Waldeyer’s ring consists of the (from top to bottom): 1 pharyngeal tonsil (or "adenoids"). 2 tubal tonsils on each side, where each auditory tube opens into the nasopharynx. 2 palatine tonsils (commonly called "the tonsils"), are located in the oropharynx 1 group of lingual tonsil are located on the back part of the tongue The anterior aspect of the nasopharynx communicates through the choanae with the nasal cavities. On its lateral wall is the pharyngeal opening of the auditory tube, and bounded behind by a firm prominence, the torus tubarius or cushion, caused by the medial end of the cartilage of the tube which elevates the mucous membrane. Two folds arise from the cartilaginous opening. The auditory tube, which connects the middle ear to the pharynx, opens into the nasopharynx at the pharyngeal opening of the auditory tube. The word salphinx is a greek synonym for the tube or trupet. A salpinx ( plural salpinges, Greek σαλπιγξ) was a trumpet-like instrument of the ancient Greeks, as a Fallopian or Eustachian tube. The opening and closing of the auditory tubes serves to equalize the barometric pressure in the middle ear with that of the ambient atmosphere. the salpingopharyngeal fold containing the salpingopharyngeus muscle. The oropharynx lies behind the oral cavity, extending from the uvula to the level of the hyoid bone. It opens anteriorly, through the isthmus faucium, into the mouth. The fauces is a part of the oropharynx directly behind the oral cavity as a subdivision, bounded superiorly by the soft palate, laterally by the palatoglossal and palatopharyngeal arches, and inferiorly by the tongue. in its lateral wall, between the palatoglossal arch and the palatopharyngeal arch, is the palatine tonsil. The anterior wall consists of the base of the tongue and the epiglottic vallecula; the lateral wall is made up of the tonsil, tonsillar fossa, and tonsillar (faucial) pillars; the superior wall consists of the inferior surface of the soft palate and the uvula. Because both food and air pass through the pharynx, a flap of connective tissue called the epiglottis closes over the glottis when food is swallowed to prevent aspiration. The epiglottis is a flap in the throat that keeps food from entering the windpipe and the lungs. The flap is made of elastic cartilage covered with a mucous membrane, attached to the entrance of the larynx. The epiglottic vallecula is a depression (vallecula) just behind the root of the tongue between the folds in the throat. These depressions serve as "spit traps"; saliva is temporarily held in the valleculae to prevent initiation of the swallowing reflex. The vallecula is an important reference landmark used during intubation of the trachea. The procedure requires the blade-tip of a Macintosh-style laryngoscope to be placed as far as possible into the vallecula in order to facilitate directly visualizing the glottis. The laryngopharynx, (Latin: pars laryngea pharyngis), is the caudal part of the pharynx; it is the part of the throat that connects to the esophagus. It lies inferior to the epiglottis and extends to the location where this common pathway diverges into the respiratory (laryngeal) and digestive (oesophageal) pathways. At that point, the laryngopharynx is continuous with the esophagus posteriorly. the superior boundary of the laryngopharynx is at the level of the hyoid bone. The oesophagus: Oesophagus is a fibromuscular tube, approximately 25cm in length, that transports food from the pharynx to the stomach. It originates at the inferior border of the cricoid cartilage (C6) (T11). and extends to the cardiac orifice of the stomach (T11). Anatomical Course The oesophagus begins in the neck, at the level of C6. Here, it is continuous superiorly with the laryngeal part of the pharynx (the laryngopharynx). It descends downward into the superior mediastinum of the thorax, positioned between the trachea and the vertebral bodies of T1 to T4. It then enters the abdomen via the oesophageal hiatus (an opening in the right crus of the diaphragm) at T10. The abdominal portion of the oesophagus is approximately 1.25 cm long – it terminates by joining the cardiac orifice of the stomach at level of T11. Cervical and carotid region (Anterior): Trachea, left recurrent larygeal nerve and pericartidum. Cervical and carotid region (Posterior): Thoracic vertebral bodies, throracic duct, ayzgos veins, descenting aorta. Cervical and carotid region (Posterior): descenting aorta is the continuation of aortic arc. Cervical and carotid region (right): On the right plevra, terminal part of azygous vein are in relation with the oesephagus. On the left side plevra, subclavian artery and thoracic duct are in relation with the oesephagus. Abdominal anatomical relations of the oesophagus: Left vagus nerve Posterior surface of the heart Right vagus nerve Left crus of the diaphragm. The oesophagus is innervated by the oesophageal plexus, which is formed by a combination of the parasympathetic vagal trunks and sympathetic fibres from the cervical and thoracic sympathetic trunks.