SGU Histology - Digestive System Questions Part 1

  1. What are lips covered externally by?
  2. What are lips covered by internally?
  3. Near the muco-cutaneous junction the skin is devoid of?
    Hair follicles
  4. The epidermis is what near the muco-cutaneous junction near the lips?
  5. What is the mucosa epithelium of the lips? In Ruminants/horses and carnivores/pigs?
    Stratified squamous epithelium. Keratinized in ruminants/horses. Nonkeratinized in carnivores/pigs.
  6. What are the labial glands in the lips? How are they distributed?
    Serous or serousmucous. Distributed in the propria-submucosa.
  7. What does the tunica muscularis consist of in the lips?
    Skeletal muscle fibers of the orbicularis oris muscle.
  8. What three layers compose the cheek?
    Outer skin, middle layer (buccinator muscle), and an internal mucosa.
  9. The mucosa of the cheeks are lined with what epithelium?
    Stratified squamous epithelium (may or may not be keratinized)
  10. The cheek mucosa in ruminants is studded with what?
    Conical buccal papillae
  11. Where are buccal glands located?
  12. Are buccal glands serous, mucous, or seromucous?
    Can be any of the three.
  13. The mucosa of the hard palate has numerous what?
    Transverse ridges or Rugae
  14. The mucosa of the Hard Palate is lined by what kind of epithelium? Thick in what species?
    Stratified Squamous Keritinized Epithelium. Thick in Ruminants.
  15. The propria-submucosa of the Hard Palate is composed of what?
    Dense network of capillaries, collagen, and reticular fibers.
  16. The palatine glands of the Hard Palate are located where? What type of gland?
    Caudal part of Hard Palate. Mucous or Seromucous gland.
  17. What kind of epithelium does the dental pad consist of?
    Heavily keratinized stratified squamous epithelium.
  18. What kind of CT is the base of the dental pad?
    Thick layer of dense irregular CT.
  19. What kind of epithelium does the soft palate have?
    Stratified squamous epithelium.
  20. The propria-submucosa of the soft palate contains what?
    Branched, tubuloacinar, mucous, or seromucous palatine glands and lymphatic tissue.
  21. The soft palate has what kind of muscles?
    Palatine muscles are skeletal fibers arranged longitudinally.
  22. What are the functions of the tongue?
    Eating, drinking, vocalization, Muscular, Epithelial specializations, sensitive and highly innervated, contains chemoreceptor sites.
  23. The tongue is covered by what kind of layer?
  24. What kind of epithelium lines the dorsal side of the Tongue?
    Stratified squamous keratinized epithelium
  25. What kind of epithelium lines the ventral side of the Tongue?
    Stratified squamous epithelium
  26. What does the mucosa of the tongue contain?
    Abundance of capillaries, arteriovenous anastomoses.
  27. How are the intrinsic lingual muscles of the tongue arranged?
    Skeletal muscles, arranged in longitudinal, transverse, and perpendicular directions.
  28. What do the lingual glands of the tongue consist of? Located?
    Seromucous glands, scattered between muscle fibers.
  29. What is on the dorsal surface of the tongue?
    Numerous macroscopic lingual papillae.
  30. What are the functions of the lingual papillae?
    Mechanical or gustatory functions.
  31. What papillae are purely mechanical and facilitate the movement of ingesta?
    Filliform, conical, and lenticular papillae.
  32. What papillae are purely gustatory and contain taste buds?
    Fungiform, vallate, and foliate papillae.
  33. The filiform papillae are what shape? Location?
    Slender, thread-like. Project above the surface of the tongue.
  34. What kind of epithelium do the filiform papillae have?
    Stratified squamous keratinized epithelium.
  35. What supports the Filiform papillae?
    Highly vascular CT core.
  36. What species have well developed filiform papillae?
    Ruminants and cats.
  37. What are the filiform papillae like in horses?
    Very fine keratinized threads.
  38. Conical lingual papillae are larger than what?
    Filiform papillae.
  39. Are conical lingual papillae highly keratinized?
  40. Where are conical lingual papillae present in dogs, cats, and pigs?
    Root of tongue. (Core of lymphatic tissue in pigs)
  41. Where are conical lingual papillae present in ruminants?
    Torus linguae.
  42. What do the Lenticular Papillae look like? Location?
    Flattened, lens-shaped projection. Present on the torus linguae of Ruminants.
  43. What type of epithelium do lenticular papillae consist of?
    Stratified squamous keratinized epithelium w/ dense irregular CT.
  44. What is the shape of Fungiform Papillae?
    Mushroom shaped.
  45. What type of epithelium do Fungiform Papillae consist of?
    Stratified squamous nonkeratinized epithelium.
  46. Do Fungiform Papillae contain taste buds?
    Yes, on the upper surface.
  47. What are the arrangements of taste buds in Fungiform Papullae?
    Sparse in horse/cattle, Numerous in sheep/pig, and Abundant in carnivores/goats.
  48. What does the core of fungiform papillae consist of?
    Rich in blood vessels and nerves.
  49. What are Vallate papillae surrounded by?
    Epithelium lined sulcus.
  50. What type of epithelium do Vallate Papillae consist of?
    Stratified squamous Nonkeratinized Epithelium.
  51. Does the Vallate papillae consist of taste buds?
    Yes. Numerous occur on the papillary side of sulcus.
  52. What is present deep to the sulcus in Vallate Papillae?
    Group of serous gustatory glands.
  53. The CT of Vallate Papillae is rich in what?
    Blood vessels and nerves.
  54. What are Foliate Papillae?
    Parallel folds of the lingual mucosa.
  55. Where are Foliate Papillae located?
    On the caudo-lateral margin of the tongue.
  56. What type of epithelium does the Foliate Papillae consist of?
    Stratified squamous nonkeratinized epithelium.
  57. Does the Foliate papillae consist of taste buds?
    Yes on sides of the folds but not in Cats.
  58. Foliate papillae are absent in what species?
  59. What type of epithelial cells are taste buds?
    Clusters of spindle shaped epithelium.
  60. How many and what types of cells are present in taste buds?
    • Sustentacular (supportive), Gustatory (taste receptor), and basal cells are present.
    • What type of cells are taste receptors?
    • Non-myelinated afferent nerve fibers.
  61. What is a lyssa?
    Cordlike structure present in the tongue of carnivores.
  62. What is a lyssa composed of?
    White adipose tissue, skeletal muscles, blood vessels and nerves.
  63. What kind of capsule encloses a lyssa?
    Dense irregular CT capsule.
  64. What is a torus lingue?
    A large prominaence on the caudal part of the dorsal surface of the Ruminant tongue.
  65. What is the dorsal lingual cartilage?
    A mid-dorsal fibroelastic cord with hyaline cartilage, skeletal muscle, and white adipose tissue.
  66. Where is dorsal lingual cartilage present?
    Inside the tongue of the horse.
  67. The tooth consists of what two parts?
    Highly mineralized structures (outer part), and Pulp cavity (central part)
  68. What are the 3 structures of the outer part of a tooth?
    Enamel, dentine, cementum
  69. What 4 things does the pulp cavity of a tooth consist of?
    Dental pulp, core of CT, blood vessels, and nerves.
  70. What is the hardest substance in the body?
  71. What is the enamel composed of?
    99% mineral (hydroxyapatite) and 1% organic matter.
  72. What is enamel produced by?
  73. What is the enamel composed of histologically?
    Long, slender rods, and enamel prisms, held together by inter-rod enamel.
  74. What is dentine composed of?
    70% minerals, 30% organic
  75. What minerals are in dentine?
    Hydroxyapatite mainly with some carbonate, magnesium, and fluoride.
  76. What is the organic part of Dentine composed of?
    Mainly collagen fibrils and glycoprotein.
  77. What is Dentine produced by?
  78. What does Cementum resemble?
  79. What is cementum composed of?
    Composed of lamellae oriented parallel to the surface of the tooth. Also has cementoytes occupying the lacunae.
  80. What are cemento-alveolar (Sharpey's) fibers composed of?
    Bundles of collagen fibers, extend from the alveolar bone into the cementum of the tooth.
  81. What do Sharpey's fibers form?
    The periodontal ligament which anchors the tooth in the alveolus.
  82. What teeth are short and cease to grow after eruption?
    Brachydont Teeth
  83. What do brachydont teeth consist of?
    Crown, neck, and root.
  84. What are the crown and root covered by in Brachydont teeth?
    Crown = enamel. Root = Cementum.
  85. What layer in Brachydont teeth lies below enamel and cementum?
    Thick layer of dentine.
  86. What are some examples of Brachydont teeth?
    All teeth of carnivores and incisors of ruminants.
  87. What teeth are long and continue to grow throughout life?
    Hypsodont teeth.
  88. What do Hypsodont teeth NOT consist of?
    No crown or neck.
  89. What are all of the Hypsodont teeth covered by?
    Cementum and enamel.
  90. Where does the enamel lie on Hypsodont teeth?
    A thick layer of dentin.
  91. What is an Infundibulum in Hypsodont teeth?
    A characteristic enamel invagination.
  92. What are some examples of Hypsodont teeth?
    Cheek teeth of ruminants, all permanent teeth of horses and canine teeth in pigs.
  93. What are the major salivary glands?
    Parotid, Mandibular, Sublingual, Zygomatic (carnivores)
  94. What are the minor salivary glands?
    Labial, lingual, buccal, and palatine. Molar (cats)
  95. What is predominant in Parotid Salivary Glands?
    Predominantly Serous.
  96. What may occasionally occur in the Parotid Salivary Glands in dogs and cats?
    Occasionally isolated mucous secretory units.
  97. What is the parotid salivary gland composed of structurally?
    Compound acinar gland.
  98. What has pyramidal shaped cells with basal nuclei surrounded by basophilic cytoplasm?
    Parotid Salivary Gland
  99. What is the apex of the Parotid Salivary gland filled with?
    Zymogen granules.
  100. Where are myoepithelial cells present between?
    Between the secretory cells and basement membranes in Parotid Salivary Gland.
  101. What is the Intercalated duct's epithelium of Partotid Salivary gland?
    Low cuboidal epithelium
  102. What type of epithelium lines the striated duct of the Parotid Salivary gland?
    Simple columnar epithelium w/ characterists striations on the basal portion.
  103. What are the striations in the striated duct caused by?
    Perpendicularly oriented mitochondria in the deep infolding of the basal cells.
  104. What type of epithelium lines the Interlobular duct of the Parotid Salivary gland?
    Simple columnar epithelium. Become stratified columnar epithelium.
  105. What type of gland is the Mandibular Salivary Gland?
    Seromucous (mixed) gland with compound tubuloacinar. Mostly mucous and serous with occasional separate serous units.
  106. Where are the serous demilunes located in Mandibular Salivary Glands?
    Occur at periphery.
  107. Where do serous demilunes discharge their secretion in Mandiublar Salivary Glands?
    Secretion through intercellular canaliculi.
  108. What type of gland is the Sublingual Salivary Gland?
    Seromucous (mixed), compound tubuloacinar gland.
  109. What is the Sublingual Salivary Gland in Cattle, sheep, and pigs?
    Almost entirely mucous.
  110. What is the Sublingual Salivary Gland in dogs and cats?
    Clusters of serous acini and the typical mucous and serous demilunes.
  111. What in the Sublingual Salivary Gland is not prominant in cats and dogs?
    Striated and intercalated ducts.
  112. In what species are the striated and intercalated ducts well developed in the sublingual salivary gland?
    Horse, ruminants, and pigs.
  113. What is the epithelium of the main duct of the sublingual salivary gland?
    Stratified cuboidal epithelium.
  114. What are Zygomatic salivary glands composed of?
    Long branched, tubuloacinar secretory units. Predominantly mucous.
  115. What are the intercalated/striated ducts like in the Zygomatic salivary gland?
  116. What is the Molar salivary gland histologically similar to?
    In Cats its similar to the Zygomatic salivary gland.
  117. Where is the molar salivary gland located?
    Near the commissure of the lips and open into oral vestibule opposite to molar teeth.
  118. What are the 4 layers in the Tubular Organs?
    Tunica Mucosa, Tunica Submucosa, Tunica Muscularis, Tunica serosa/adventitia
  119. What are the 3 layers of Tunica Mucosa in Tubular Organs?
    Epithelium, Lamina propria (loose CT), Lamina muscularis.
  120. The tunica Mucosa of the esophagus has what type of epithelium?
    Stratified squamous epithelium. Nonkeratinized in dog, slightly keratinized in pigs/horses, and highly keratinized in ruminants.
  121. The lamina propria of the Tunica Mucosa (esophagus) consists of?
    Dense network of fine collagen fibers with an abundance of elastic fibers.
  122. What does the lamina muscularis of the Tunica Mucosa (esophagus) consist of?
    Longitudinally oriented smooth muscle bundles.
  123. What does the tunica submucosa (esophagus) consist of?
    Loost CT with blood vessels and nerves. Seromucous glands.
  124. Where are the seromucous glands located in the tunica submucosa (esophagus) of horses/cats/ruminants?
    Pharyngoesophageal junction
  125. Where are the seromucous glands located in the tunica submucosa (esophagus) of pigs?
    Cranial half of the esophagus.
  126. Where are the seromucous glands located in the tunica submucosa (esophagus) of dogs?
    Throughout its length.
  127. What is the tunica muscularis (esophagus)?
    Inner circular and outer longitudinal layer of muscles.
  128. What is the muscle in the tunica muscularis (esophagus) in dogs?
    Entirely striated muscle.
  129. What is the muscle in the tunica muscularis (esophagus) in horses?
    Cranial 2/3 = skeletal m. Caudal 1/3 smooth m.
  130. What layer of the tunica muscularis (esophagus) thickens at the cardia, especially in horses?
    The inner circular layer, forming the cardiac sphincter.
  131. The tunica adventitia (esophagus) is located where?
    The cervical region.
  132. The tunica serosa (esophagus) is located where?
    The thoracic and abdominal region.
  133. What is the tunica adventitia/serosa composed of?
    Loose CT, blood vessels, and nerves.
  134. What is the only glandular part of a compound stomach?
  135. Nonglandular part of stomach is absent and small in what species?
    Absent = Carnivores and Small = pigs.
  136. What is the nonglandular region of a horse's stomach separated by?
    The margoplicatus separates the glandular region.
  137. In what species is the nonglandular part of the stomach most prominent?
  138. The epithelium of the nonglandular stomach is what?
    Stratified squamous epithelium. (can be keratinized).
  139. The mucosa of the Rumen is characterized by what?
    Small tongue shaped papillae.
  140. The epithelium of the Rumen consists of?
    Stratified Squamous Keratinized Epithelium.
  141. Each papillae's (Rumen) core consists of?
    Dense feltwork of collagen, elastic, and reticular fibers.
  142. What type of capillaries lie just beneath the epithelium of the Rumen?
    Dense network of fenestrated capillaries.
  143. The lamina muscularis is absent in what?
  144. What is the tunica muscularis composed of in Rumen?
    Inner circular and outer longitudinal layer of smooth muscle.
  145. The tunica serosa is covered by what in the Rumen?
    Mesothelium (fat, blood vessels, and nerves)
  146. The mucosa of the Reticulum is characterized by what?
    Reticular folds w/ vertical ridges on their sides.
  147. The mucosa between the folds of the Reticulum is covered by?
    Conical papillae which project into the lumen.
  148. What is the epithelium of the Reticulum?
    Stratified squamous keratinized epithelium.
  149. The Propria-submucosa (reticulum) is formed by what?
    • Feltwork of collagen and elastic fibers. Smooth muscle in the upper reticular fold.
    • What does the tunica muscularis (reticulum) consist of?
    • Two layers of smooth muscle fibres that follow an oblique course and cross at right angles.
  150. The tunica serosa (reticulum) is like the corresponding tunica serosa in what?
  151. Where does the Reticular Groove extend?
    From the cardia to the reticulo-omasal orifice.
  152. What is the Reticular Groove bordered by?
    Two thick folds, labia (lips).
  153. In young animals what happens to the reticular groove when sucking?
    Smooth muscle layers of labia contract creating a channel that allows the milk to bypass the rumen and reticulum.
  154. What does the Omasum mucosa have that is characteristic?
    Omasal Laminae (leaves) w/ macroscopic papillae.
  155. What is the epithelium of the Omasum?
    Stratified squamous keratinized epithelium.
  156. What does the Lamina propria (omasum) contain?
    A dense subepithelial capillary network.
  157. The lamina muscularis (omasum) forms what?
    A thick layer beneath the lamina propria on both sides of the laminae.
  158. The submucosa (Omasum) is what?
    Very thin.
  159. What are the two layers of the tunica muscularis (Omasum)?
    Thin outer longitudinal layer and a thicker inner circular layer of smooth muscle.
  160. The innermost layer of the Tunica Muscularis (Omasum) continues into what?
    Continues into the omasal laminae.
Card Set
SGU Histology - Digestive System Questions Part 1
The first two lectures of Histology in Question format.