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• Mouth and throat


  Comprise the first part of the digestive system
• Functions of mouth and throat

  • Receiving food (ingestion)
  • Tasting and preparing food for digestion
  • Aiding in speech
• Cranial nerves related to mouth and throat

  • V (trigeminal)
  • VII (facial)
  • IX (glossopharyngeal)
  • XII (hypoglossal)
• Mouth (oral cavity)


  First part of the digestive system that is formed by the lips, cheeks, hard and soft palates, uvula, and the tongue and its muscles

  
• Functions of the mouth

  • Serves as an airway for the respiratory tract
  • Consists of the: tongue, teeth, gums, and salivary glands (parotid, submandibular, and sublingual)
• Palate


  Roof of oral cavity, formed by the anterior hard palate and posterior soft palate, separates the oral cavity from the nasal cavity, prevents food from passing into the nasal cavity during chewing and swallowing
• Lips, cheeks, and tongue

  • Lips form the entrance to the mouth and serve as a protective gateway to the digestive and respiratory tract
  • Cheeks form the lateral walls of the mouth, located within buccinator muscles that flatten cheeks against teeth, important for mastication (chewing)
  • Tongue forms the floor of the mouth, mass of muscle attached to the hyoid bone and styloid process, contains frenulum and papillae, carries sensory impulses to the brain via taste buds

  
• Uvula, mandible, and gums

  • Uvula is an extension of the soft palate that hangs in the posterior midline of the oropharynx
  • Mandible (jawbone) provides the structural support for the floor of the mouth
  • Gums (gingiva) are covered by mucous membrane and normally hold 32 teeth in adults and 20 for babies

  
• Teeth

  Adults have 32 teeth whereas babies have 20, crown is the top visible white enameled part, root is the largest portion embedded in the gums, neck connects the crown and root

  
• Salivary glands

  • Produce saliva, a watery, serous fluid containing salts, mucus, and salivary amylase that helps break down food and lubricates it
  • Parotid glands are located below and in front of the ears and empty through Stensen ducts
  • Submandibular glands are located in the lower jaw and open under the tongue through Wharton ducts
  • Sublingual glands are located under the tongue and open through several ducts on the floor of the mouth

  
• Tonsils


  • Help protect against infection, palatine tonsils are masses of lymphoid tissue located on both sides of the oropharynx, lingual tonsils lie at the base of the tongue, pharyngeal tonsils (adenoids) are found high in the nasopharynx
• Abdomen


  Bordered superiorly by the costal margins, inferiorly by symphysis pubis and inguinal canals, and laterally by the flanks
• Abdominal quadrants


  • Determined by an imaginary vertical line (midline) from the tip of the sternum (xiphoid) through the umbilicus to the symphysis pubis, bisected perpendicularly by the lateral line running through the umbilicus across the abdomen
  • Four quadrants: right upper, right lower, left upper, left lower

  
• Abdominal regions

  Nine regions divided into three parts: epigastric, umbilical, hypogastric / suprapubic

  
• Abdominal wall muscles


  • Protect the internal organs and allow normal compression during functional activities
  • Three layers: outermost external abdominal oblique, middle internal abdominal oblique, innermost transverse abdominis
  • Rectus abdominis is a vertical muscle of the anterior abdominal wall
• Imaginary vertical line (midline)

  From the tip of the sternum (xiphoid) through the umbilicus to the symphysis pubis
• Lateral line

  Runs through the umbilicus across the abdomen, bisecting the midline perpendicularly
• Four quadrants of the abdomen


  • Right upper quadrant (RUQ)
  • Right lower quadrant (RLQ)
  • Left upper quadrant (LUQ)
  • Left lower quadrant (LLQ)
• Nine regions of the abdomen

  • Epigastric
  • Umbilical
  • Hypogastric / suprapubic
• Abdominal wall muscles

  • Protect the internal organs and allow normal compression during functional activities
  • Three layers: external abdominal oblique, internal abdominal oblique, transverse abdominis
• Rectus abdominis


  A vertical muscle of the anterior abdominal wall
• Linea alba


  White line at the midline of the abdomen formed from the joining of muscle fibers and aponeuroses, extends vertically from the xiphoid process to the symphysis pubis
• Parietal peritoneum


  Thin, shiny serous membrane that lines the abdominal cavity
• Visceral peritoneum


  Provides a protective covering for most of the internal abdominal organs
• Abdominal cavity comprises


  • Gastrointestinal tract
  • Female reproductive system
  • Lymphatic system
  • Urinary system
• Abdominal viscera

  • Solid viscera
  • Hollow viscera
• Solid viscera


  Organs that maintain their shape consistently (liver, pancreas, spleen, adrenal glands, kidneys, ovaries, uterus)
• Hollow viscera


  Structures that change shape depending on their contents (stomach, gallbladder, small intestine, colon, bladder)
• Liver


  • Largest solid organ in the body
  • Located below the diaphragm in the RUQ of the abdomen
  • Composed of four lobes that fill most of the RUQ and extend to the left midclavicular line (LMCL)
• Pancreas


  • Located mostly behind the stomach, deep in the upper abdomen
  • An endocrine gland
  • Accessory organ of digestion
• Spleen


  • Approximately 7cm wide
  • Located above the kidney just below the diaphragm at the level of the 9th, 10th, and 11th ribs
  • Posterior to the left midaxillary line and posterior and lateral to the stomach
  • Filters the blood of cellular debris, digests microorganisms, returns breakdown products to the liver
• Kidneys


  • Located high and deep under the diaphragm, at the level of T12 to L3 vertebrae
  • Filtration and elimination of metabolic waste products
  • Play a role in blood pressure control and maintenance of water, salt, and electrolyte balances
  • Function as an endocrine gland by secreting hormones
• Ovaries


  • Located in the RLQ and LLQ, normally palpated through bimanual examination of the internal genitalia
• Stomach


  • Where the abdominal cavity begins
  • Distensible, flask-like organ located in the LUQ below the diaphragm and between the liver and spleen
  • Stores, churns, and digests food
• Gallbladder


  • Approximately 10cm long
  • Located near the posterior surface of the liver lateral to the MCL
  • Concentrates and stores the bile needed to digest fat
• Small intestine


  • Longest portion of the digestive tract, approximately 7m long and 2.5cm in diameter
  • Digestion and absorption of nutrients
• Colon (large intestine)

  • Approximately 1.4m long and 6cm in diameter
  • Originates in the RLQ, where it attaches to the small intestine at the ileocecal valve
  • Composed of ascending, transverse, and descending sections
  • Secretes large amounts of alkaline mucus to lubricate the intestine and neutralize acids formed by the intestinal bacteria
  • Where water is absorbed, leaving waste products to be eliminated in stool
• Urinary bladder


  • Distensible muscular sac located behind the pubic bone in the midline of the abdomen
  • Temporary receptacle for urine
• Abdominal aorta


  • Pulsations are visible and palpable midline in the upper abdomen
  • Branches into the right and left iliac arteries below the umbilicus
• Right and left iliac arteries

  • Pulsations may be felt in the RLQ and LLQ