MOD 5 - DIGESTIVE SYSTEM

• What are the two main components of the digestive system?

  • Alimentary tract
  • Accessory organs of digestion
• What is the alimentary tract?

  A continuous passage from mouth to anus
• What processes occur in the alimentary tract?

  Digestion and absorption of food products
• What are the accessory organs of the digestive system?

  • Salivary glands
  • Liver
  • Pancreas
• What do accessory organs contribute to digestion?

  They produce enzymes, buffers, and emulsifiers
• What is the function of the oral cavity?

  Ingestion, mastication, and lubrication
• What are the two divisions of the oral cavity?

  • Oral vestibule
  • Oral cavity
• What type of epithelium covers the lining mucosa of the oral cavity?

  Non-keratinized stratified squamous epithelium
• What is the role of the oral mucosa?

  Provides a barrier against pathogens and toxins
• What is the lamina propria?

  A thin layer of loose connective tissue
• What is the function of the submucosa in the oral cavity?

  Contains minor salivary glands and supports mucosa
• What are the characteristics of masticatory mucosa?

  • Keratinized stratified squamous epithelium
  • Exposed to significant abrasion
  • Thick lamina propria
• What are the types of papillae on the tongue?

  Filiform, fungiform, circumvallate, foliate
• What is the main function of the specialized mucosa on the tongue?

  Mix food during chewing
• What are the three surfaces of the lips?

  • Internal mucous surface
  • Vermilion zone
  • Outer surface
• What is the primary function of the vermilion zone of the lips?

  Transition zone between oral mucosa and skin
• How many permanent teeth do adults typically have?

  32 permanent teeth
• What is the crown of a tooth?

  Part of the tooth exposed above the gum
• What is the hardest component of the human body?

  Enamel
• What is the function of cementum?

  Covers the roots of the teeth
• What is the role of dental pulp?

  Contains blood vessels and nerves
• What structures make up the periodontium?

  • Cementum
  • Periodontal ligaments
  • Alveolar bone with gingiva
• How long is the esophagus in adults?

  About 25 cm long
• What is the primary function of the esophagus?

  Transport swallowed material to the stomach
• What type of muscle makes up the upper third of the esophagus?

  Skeletal muscle
• What type of muscle makes up the lower third of the esophagus?

  Smooth muscle
• What are the functions of the stomach?

  • Continuation of carbohydrate digestion
  • Mix contents into chyme
  • Begin triglyceride digestion
  • Promote protein digestion
• What is the name of the viscous mass formed in the stomach?

  Chyme
• What are the four regions of the stomach?

  Cardia, pylorus, fundus, body
• What are gastric glands responsible for?

  • Secreting gastric juice
  • Releasing acidic gastric juice
• What do parietal cells secrete?

  Hydrochloric acid and intrinsic factor
• What is the pH of gastric juice?

  About 2.0
• What stimulates HCl secretion in the stomach?

  Gastrin, histamine, and acetylcholine
• What is the role of enteroendocrine cells?

  • Secrete hormones
  • Regulate gastric secretion
• What type of category does not have processes reaching the lumen?

  Closed category
• What do enteroendocrine cells secrete?

  Only one hormone each
• What organelles are abundant in enteroendocrine cells?

  Mitochondria and rough endoplasmic reticulum
• What is the pH of gastric juice?

  pH 2.0
• What does gastric juice facilitate the activation of?

  Pepsinogen to pepsin
• What regulates gastric secretion?

  Neural activity and hormones