SGU Histology3

  1. What are the lips covered by?
    • Externally - integument
    • Internally - mucosa

  2. The mucosa of the lips is covered by what type of epithelium?
    • Stratified squamous epithelium
    • Keratinized - ruminants and horses
    • Non-keratinized - carnivores and pigs
  3. What is found in the cutaneous area of the lips but missing in the mucosa area?
    • Hair follicles
    • Sweat and sebaceous glands
  4. What type of glands are usually found in the lips and where are they located?
    • Seromucous
    • Propria-submucosa
  5. What type of muscle is found in the tunica muscularis of the lips?
    Orbicularis oris muscle
  6. What are the layers of the tubular organs?
    • Tunica mucosa (Epithelium, tunica propria, tunica muscularis)
    • Tunica submucosa
    • Tunica muscularis
    • Tunica serosa/adventitia
  7. What happens when lamina muscularis is absent?
    Lamina propria joins with tunica submucosa to form propria-submucosa
  8. What are the layers of the cheeks?
    • Outer skin
    • Middle muscular layer (buccinator muscle)
    • Internal mucosa
  9. In what animals is the mucosa of the cheeks studded with conical buccal papillae?
  10. What are the transverse ridges on the mucosa of the hard palate?
  11. How many incisors do ruminants have?
    • None
    • They have a dental pad which consists of a heavily keratinized stratified squamous epithelium
  12. What is the raised part of the tongue in ruminants?
    Torus linguae
  13. What are the characteristics of the muscles of the tongue?
    • Skeletal muscles
    • Arranged in longitudinal, transverse and perpendicular direction
  14. What is glossitis?
    Inflammation of the tongue
  15. What is inflammation of the oral cavity?
  16. What is the epithelium of the tongue?
    • Stratified squamous epithelium
    • Keratinized on dorsal surface
    • Nonkeratinized on ventral surface
  17. What are the functions of lingual papillae?
    • Mechanical - movement of ingesta
    • Gustatory - contains taste buds
  18. What type of lingual papillae is lenticular papillae?
  19. What are the types of mechanical papillae?
    Filiform, conical, lenticular
  20. What are the types of gustatory papillae?
    • Fungiform
    • Vallate
    • Foliate
  21. Which type of papillae are slender, keratinized, thread-like structures that project above the surface of the tongue and are abundant in cats and ruminants?
    Filiform, mechanical
  22. Which type of papillae are larger than filiform papillae and on the torus linguae of ruminants?
    Conical, mechanical
  23. Which type of papillae are flattened lens-shaped projections and present on the torus linguae of ruminants?
    Lenticular, mechanical
  24. Which papillae have taste buds on the upper surface?
    Fungiform, gustatory
  25. Which papillae are surrounded by an epithelium lined sulcus and have taste buds on the papillary side of the sulcus?
    Vallate, gustatory
  26. Which type of papillae are parallel folds of the lingual mucosa with taste buds on the sides of the folds?
    Foliate, gustatory
  27. What are the types of cells in the taste bud?
    • Sustentacular (supportive)
    • Gustatory (taste receptors)
    • Basal cells
  28. What do basal cells in the taste buds do?
    Replace sustentacular and gustatory cells when needed
  29. What is a cordlike structure present in the tongue of carnivores, composed of white adipose tissue and enclosed by a dense irregular connective tissue capsule?
  30. What is the mid-dorsal fibroelastic cord inside the tongue of the horse?
    Dorsal lingual cartilage
  31. What type of tongue do birds have?
    Entoglossal tongue (bone in tongue)
  32. What are the parts of a tooth?
    • Pulp cavity
    • Highly mineralized structures:
    • -Enamel
    • -Dentine
    • -Cementum
  33. What is produced by ameloblasts?
  34. What is enamel composed of?
    • 99% mineral (hydroxyapatite)
    • 1% organic matter
  35. What is produced by odontoblasts?
  36. What is dentine composed of?
    • 70% minerals (mainly hydroxyapatite)
    • 30% organic material
  37. What forms the periodontal ligament, which anchors the tooth in the alveolus?
    Bundles of collagen fibers, called cemento-alveolar (Sharpey's) fibers, extending from the alveolar bone into the cementum
  38. Which type of teeth are short and cease to grow after eruption is completed?
  39. What are the layers of brachydont teeth?
    • Enamel - covers the crown
    • Cementum - covers the root
    • Dentine - thick layer beneath both the enamel and cementum
  40. What are examples of brachydont teeth?
    • All teeth of carnivores
    • Incisors of ruminants
  41. Which type of teeth are longer and continue to grow throughout life?
    Hypsodont teeth
  42. What are the layers of hypsodont teeth?
    • Cementum and enamel cover the length of the teeth
    • Cementum is outer layer
    • Enamel lies on a thick layer of dentine
  43. What is a characteristic enamel invagination in hypsodont teeth?
  44. What are examples of hypsodont teeth?
    • Cheek teeth of ruminants
    • Canines of pigs and elephants
    • All permanent teeth of horses
  45. What are the major salivary glands?
    • Parotid
    • Mandibular
    • Sublingual
    • Zygomatic (carnivores)
  46. The parotid salivary gland is predominantly ____.
  47. What cells are present between the secretory cells and basement membranes of parotid gland?
    Myoepithelial cells
  48. What are the different ducts of the parotid salivary gland?
    • Intercalated duct
    • Striated duct
    • Interlobular duct
    • Main duct
  49. What type of epithelium lines the intercalated ducts?
    Low cuboidal
  50. What are the characteristics of striated ducts?
    Simple columnar epithelium with striations in the basal portions of the cells
  51. What type of gland is the mandibular salivary gland?
    • Seromucous (mixed)
    • Compound tubuloacinar
  52. What type of gland is the sublingual salivary gland?
    • Seromucous
    • Compound tubuloacinar
  53. What type of gland is the zygomatic salivary gland?
    • Long branched, tubuloacinar
    • Mainly mucous with flattened serous demilune
  54. Which gland is histologically similar to the zygomatic salivary gland, located near commisure of the lips and their ducts open into oral vestibule opposite to molar teeth?
    Molar salivary gland
  55. Which animals have a molar salivary gland?
  56. Which animal has nonkeratinized stratified squamous epithelium in the esophagus? Keratinized?
    • Dog
    • Ruminants
  57. What are the minor salivary glands?
    • Labial
    • Lingual
    • Buccal
    • Palatine
    • Molar
  58. What type of glands are in the tunica submucosa of the esophagus?
  59. In what animals is the tunica muscularis in the esophagus entirely striated? Up to two-third striated? Four-fifth of the length?
    • Ruminant and dog
    • Horses
    • Cats
  60. Which animals have a prominent cardiac sphincter?
  61. What forms the cardiac sphincter?
    Thickening of the inner circular layer of tunica muscularis at the cardia of the stomach
  62. Where does the esophagus change from tunica adventitia to tunica serosa?
    • Tunica adventitia - cervical region
    • Tunica serosa - thoracic (pleura) and abdominal (peritoneum) regions
  63. What are the four chambers of the ruminant stomach?
    • Rumen
    • Reticulum
    • Omasum
    • Abomasum
  64. What is the glandular region of the ruminant's stomach?
  65. What animal has a margoplicatus?
  66. What separates the nonglandular region from the glandular region in the horse?
  67. What is the epithelium of the nonglandular region of the stomach?
    Stratified squamous epithelium keratinized
  68. What lines the mucosa of the rumen?
  69. What layer is absent in the rumen?
    Lamina muscularis - forms a propria-submucosa
  70. What is the tunica serosa of the rumen covered by?
  71. What lines the mucosa of the reticulum?
    Reticular folds
  72. What covers the mucosa between reticular folds and projects into the lumen?
    Conical papillae
  73. What are the characteristics of the tunica mucosa in the reticulum?
    • The lamina muscularis is absent, forming a propria-submucosa
    • A band of smooth muscles is located in the upper part of the reticular fold
  74. What extends from the cardia to the reticulo-omasal orifice, creating a bypass of the rumen and reticulum in young animals?
    Reticular groove
  75. In the young ruminant, what contracts to create a channel allowing milk to bypass the rumen and reticulum?
    Smooth muscle layers of the labia (two thick folds bordering the reticular groove)
  76. What lines the omasal mucosa?
    Omasal laminae or 'leaves' studded with macroscopic papillae
  77. What is a characteristic of the omasum?
    • Lamina muscularis is present and forms a thick layer beneath the lamina propria on both sides of the omasal leaves
    • Innermost layer of the tunica muscularis is continued into the omasal laminae as the intermediate muscle sheet
  78. What are the regions of the glandular stomach?
    • Cardiac
    • Fundic
    • Pyloric
  79. What are the small invaginations of the glandular stomach?
    Gastric pits, which are continuous with the gastric glands
  80. What type of epithelium lines the mucosal surface and gastric pits of the stomach?
    Simple columnar epithelium
  81. In what layer are the gastric glands densely packed?
    Lamina propria
  82. In what animal is the cardiac gland region most developed?
  83. What type of glands are in the cardiac gland region?
    • Simple branched, coiled tubular
    • Mucous
  84. What are the characteristics of the gastric pits and glands of the cardiac gland region?
    • Gastric pits - shallow
    • Gland region - deeper
  85. What are the parts of the fundic glands?
    • Short neck
    • Long body
    • Slightly dilated blind end
  86. What are the cell types that comprise the secretory epithelium of the fundic gland region?
    • Mucous neck cells
    • Chief (zymogen) cells
    • Parietal cells
    • Endocrine cells
  87. Which are the most numerous cells of the fundic gland region?
    Chief (zymogen) cells
  88. What do the chief cells secrete?
    Pepsinogen, which is transformed into pepsin by hydrochloric acid
  89. What are the characteristics of parietal cells?
    • Larger and less numberous than chief cells
    • Occur singly
  90. How do parietal cells stain?
    The cytoplasm stains deeply with eosin
  91. What do parietal cells form?
    Hydrochloric acid (they contain an abundance of carbonic anhydrase)
  92. What are endocrine cells responsible for?
    Production of GIT hormones
  93. What is used to stain endocrine cells and, thus, what are they also called?
    • Silver stain
    • Argentaffin cells
  94. What are the characteristics of the gastric pits and glands of the pyloric gland region?
    • Gastric pits - deeper
    • Gland region - shorter
  95. What forms the pyloric sphincter?
    Middle circular layer of the tunica muscularis of the pyloric gland region
  96. What type of cells are in the pyloric gland region?
  97. How many layers are in the tunica muscularis of the stomach?
    • 3 :
    • Inner oblique
    • Middle circular
    • Outer longitudinal
  98. What is the function of the lamina muscularis in the stomach?
    Helps in the emptying of the glands
  99. What makes up the tunica submucosa of tubular organs?
    • Connective tissue
    • Glands
    • Submucosal (Meissner's) plexus
  100. What makes up the tunica muscularis of tubular organs?
    • Smooth or skeletal muscles
    • Myenteric (Auribach's) plexus
  101. What specialized structures facilitate the digestive and absorptive functions of the small intestine?
    • Mucosal folds - in the cranial two-thirds
    • Villi - finger-like projections (only in the SI)
    • Microvilli - on the free surface of the simple columnar epithelial cells
  102. What epithelium lines the small intestine?
    Simple columnar epithelium
  103. T/F: The density of the goblet cells is greater in the caudal part of the small intestine (ileum).
  104. What are the simple branched tubular invaginations at the base of the villi?
    Crypts of Lieberkuhn (intestinal glands)
  105. Where are crypts of Lieberkuhn located?
    Small and large intestine
  106. What lines the crypts of Lieberkuhn?
    Low columnar cells, which multiply and migrate onto the villus, giving rise to the columnar and goblet cells
  107. What cells are present near the base of the intestinal gland (crypts of Lieberkuhn) in ruminants and horses?
    Paneth cells
  108. What are the characteristics of Paneth cells?
    • Pyramid-shaped cells with prominent acidophilic granules
    • Produce peptidase and lysozyme, an antibacterial compound
  109. What other cells are present in the intestinal gland?
    Enteroendocrine (argentaffin) cells
  110. What forms the core of the villi and surrounds the intestinal glands?
    Lamina propria
  111. T/F: The number of lymphatic nodules decreases towards the ileum.
  112. What is located in the center of the villus, which is the origin of the lymph vessels?
    The lacteal
  113. What is responsible for the movement of blood and lymph?
    Lamina muscularis, which extends to the tip of the villi
  114. What is present in the tunica submucosa of the jejunum?
    Nothing special, just CT, blood vessels and nerves
  115. What is present in the tunica submucosa of the duodenum?
    Brunner's glands - tubuloalveolar submucosal glands
  116. What is present in the tunica submucosa of the ileum?
    Peyer's patches - large aggregated lymphatic nodules, produce B-lymphocytes
  117. Which animal has the thickest tunica muscularis in their small intestine?
  118. What are special characteristics of the large intestine?
    • Absence of villi
    • More goblet cells
    • Absence of Paneth cells
    • Increase in number of lymphatic nodules
    • Plicae circulares (mucosal folds) are absent but longitudinal folds are present
  119. Where is the largest number of goblet cells?
  120. Why is the mucosa of colon substantially thicker?
    Increased length of intestinal glands
  121. What are taenia?
    Flat muscle bands containing numberous elastic fibers formed by the outer longitudinal layer of the tunica muscularis of the large intestine in pigs and horses
Card Set
SGU Histology3
Digestive, respiratory, urinary, reproductive systems