Module 4

• Buccal cavity

  • oral opening bounded by lips
  • opens into buccal cavity
• Cheeks


  prevents food loss
• Palatoglossal arch


  part of the buccal cavity the is located between the mouth and pharynx
• Hard Palate 


  located on the roof of the buccal cavity
• Primary palate 


  combination of medial + lateral series of skull bones
• Internal nares

  • also known as choanae
  • connect nasal passages with mouth
• Secondary palate

  • forms from the fusion of the palatal folds meeting in the midline
  • anterior (hard) margin
  • posterior (soft) margin
  • function: allows mammals and crocodiles to transpire or breathe while eating
• Teeth

  • dentin capped with enamel/oid
  • mechanical digestion in mammal and other vertebrate groups
  • derived from scleroblast
• Occlusion

  allows catching and crushing of prey
• Odontoblast

  • cells that produces dentin
• Outside-in-Theory 


  teeth arose from denticles moving inwards with stomodeum into buccal cavity with developing jaws
• Inside-out Theory 


  teeth in the pharyngeal region progressed forward into the buccal cavity
• Hard tissues on the tooth

  1. Enamel - on crown surface
  2. Dentin - pulp cavity walls; incremental growth
  3. Cementum - on the surface of roots; pulse deposits
• Homodont 


  similar appearance throughout the mouth
• Heterodont


  different appearance throughout the mouth
• Polyphyodont dentition 


  continuous tooth replacement throughout life
• Diphyodont dentition 


  only 2 sets of teeth - Deciduous and permanent
• Thecodont 


  tooth into sockets within bone
• Acrodont

  shallow sockets; teeth attached to crest
• Pleurodont 


  teeth attached to medial side of the bone
• the tongue is derived from the hypobranchial musculature
• Label the parts

  A) crown

  B) root

  C) cusp

  D) enamel

  E) dentin

  F) pulp cavity

  G) cementum

  H) root canal

  I) apical foramen

  
• Label the parts

  A) canines

  B) incisors

  C) premolars

  D) molars

  
• Label the parts

  A) Buccal cavity

  B) pharynx

  C) alimentary canal

  D) esophagus

  E) stomach

  F) large intestine

  G) small intestine

  
• Label the parts

  A) salivary glands

  B) liver

  C) panreas

  
• Label the parts

  A) alimentary canal

  B) digestive tract

  C) pharynx

  D) Buccal cavity

  E) cloaca

  
• Rugae

  • specialization of the esophagus
  • increase surface area
• The muscular layer of esophagus is made of striated muscle
• Esophagus of fishes: directly connects to the anterior portion of small intestine (agastric fishes without stomach)
• Agastric fishes: fishes without stomach
• Amphibians 


  they have short esophagus compared to the rest of alimentary canal
• Muscularis externa 


  made up of smooth muscle

  • smooth muscle is involuntary with slow-sustained contraction
• Spiral valve


  specializations of alimentary canal in sharks
• Humans


  their specialization of the alimentary canal involves coiling and lengthening of the alimentary canal (long small intestine for longer time of absorption)
• Typhlosole

  • found in lampreys (ammocoetes)
  • lateral projection of the intestine
  • function: increase surface area for better digestion and absorption
• Crop

  • found in many modern Aves
  • esophagus enlarges for temporary storage of food
  • chemical digestion may also begin here like seeds
• Cecum

  • found in the large intestine
  • function: temporary storage of broken down food
• Ruminant

  • Artiodactyl-hooved animals that ferment their own food
• Fermenting machine

  • in ruminants
  • associated with espohagus
  • rumen
  • reticulum
  • omasum
• Camel


  they are not ruminants but they can also ferment their own food