ANATOMY

• primary function of digestive system

  breakdown of food into small molecules and absorption of these molecules/nutrients. Storage and release of solid waste.
• ancillary organs

  organs that help with digestion but are not a part of digestive tract (tongue, pancreas, liver, gallbladder)
• gastrointestinal tract


  also called alimentary canal. Continuous tube from mouth to anus. Mechanical and chemical digestion as well as absorption
• cranial digestive structures

  salivary glands, oral cavity, pharynx, esophagus
• salivary glands


  multiple glands in the cheek/oral area that aid in the beginning of digestion
• parotid gland

  large, lobular gland lying below the ear along caudal border of the mandible. Creates saliva/amylase for the mouth
• parotid duct

  crosses over surface of the masseter and enters oral cavity from cheek wall. Carries saliva to the mouth
• submandibular gland


  lobular gland lying caudal to the angle of the jaw ventral to the parotid. Generates amylase and mucus for mouth
• infraorbital gland


  located under the eye in its orbit. Produces alkaline/saline tears to moisten eye
• vestibule


  region located between teeth and cheeks. Keeps food between teeth and is an entry point for saliva
• teeth

  4 incisors and 16 molars. Agents of mechanical digestion
• hard palate


  rostal portion of the roof of the mouth formed by bones and lines with mucus membrane. Surface for food compression, creates phonetic sounds, separates oral from nasal
• soft palate


  caudal portion of the roof of the mouth. Muscular piece between two chambers of the pharynx. Closes off nasal passages during swallowing
• tongue


  large muscular structure that makes up the floor of the oral cavity. Vital for chewing swallowing tasting and sound
• lingual frenulum


  ventral fold of the mucus membrane where the tongue attaches. Involved in tongue movement
• lingual torus


  elevated region on the underside of the tongue
• median lingual sulcus

  central groove which divides the tongue into right and left halves
• papillae


  extensions of the mucus membrane on the tongue containing taste buds
• taste buds


  house receptor cells that are sensitive to chemical stimulation or taste
• palatoglossal arches


  lateral folds on both sides of the cavity wall, tongue to soft palate. Facilitates movement of food, separates chewing from swallowing
• fauces


  space between buccal cavity and the pharynx after the palatoglossal arches. Facilitates movement of food to the pharynx
• pharynx

  behind soft palate. Passageway for air, food. Branches into trachea and esophagus (throat)
• nasopharynx


  dorsal to the end of the soft palate. Acts as an airway, contains the tonsils and provides a drainage path for lymphatic fluids
• internal auditory canal

  two small slit-like openings on the laterodorsal walls of the nasopharynx. Aid in communication with the middle ear
• oropharynx

  behind the soft palate ending at epiglottis. Works with respiratory and digestive. Swallowing, involuntarily and voluntarily
• platine tonsils


  embedded in laterodorsal wall of the pharynx. Thought to aid in defending the body from respiratory infections
• laryngopharynx


  caudal-most portion of pharynx. Immediately cranial to the larynx. Communicates w epiglottis and guides food and air to appropriate places
• glottis


  opening of the larynx from laryngopharynx. Voicing sounds as vocal folds vibrate
• epiglottis


  moveable fold atop the glottis. Keeps food out of windpipe. Coordinates food to GI and air to lungs
• esophagus


  dorsal to trachea and travels length of thoracic cavity. Transports material from pharynx to stomach
• diaphragm


  circular sheet of muscle dividing thoracic and abdominal cavities. Main muscle of respiratory system, contraction expands the lungs
• abdominopelvic cavity


  cavity from pelvis to diaphragm. Contains many important organs and protects caudal digestive structures.
• peritoneum


  extensive serous membrane lining AP cavity and visceral organs. Serves as a conduit for blood and lymph vessels as well as nerves
• parietal peritoneum

  portion of peritoneum that lines the internal surface of abdominal wall
• visceral peritoneum


  portion of peritoneum that covers visceral organs
• peritoneal cavity


  cavity between two peritoneal membranes. Contains fluid to help reduce friction of adjacent organs. Allows fluid movement and reduces injury
• mesentary


  double layer of peritoneum that extends from visceral peritoneum of small/large intestines to the abdominal wall. Anchors organs and supplies them with nerves and blood vessels
• stomach


  j-shaped organ located directly beneath the diaphragm. Chemical digestion of food with pepsin to break down protein. Also mechanical digestion with churning
• greater curvature


  lateral border of stomach forming rounded convex surface
• lesser curvature


  medial border of stomach forming smooth concave angle