Lab

• Coelom


  A cavity associated with both the digestive and the respiratory systems and the pericardial cavity that surrounds the heart. Its functional importance is that it allows the organs of the systems it encloses to move freely within and facilitates their action.
• Coelom


  • Body cavity of vertebrates
  • Cavity of the hypomere
  • Never segmented
  • Outer wall comes in contact with the inner surface of the layer of voluntary muscles
  • Forms the lining of the body wall
• Parietal peritoneum


  Lining of the body wall
• Visceral peritoneum or serosa

  Inner walls of the hypomeres of the two sides become the covering layer of the intestine and other viscera
• Mesentery


  A double-walled membrane formed from the two walls of the hypomere (above and below the intestine) in contact
• Dorsal mesentery


  Portion of the mesentery between the dorsal wall of the coelom and the intestine. In mammals it is often a site for fat deposition.
• Mesogaster


  Greater omentum, portion of the dorsal mesentery attached to the stomach
• Mesoduodenum


  Associated with the duodenum
• Mesointestine


  Supports the small intestine
• Mesorectum


  Connected to the rectum
• Ventral mesentery


  Between the ventral wall and the intestine, reduced in size and persists only as few specialized ligaments
• Falciform ligament


  Attaches the anterior end of the liver to the ventral body wall
• Gastroduodenohepatic ligament


  Lesser omentum, connects the stomach to the liver and duodenum
• Median ligament


  Lies between the urinary bladder and the ventral body wall
• Peritoneum


  A lateral mesentery such as the mesovarium and mesorchium
• Mesovarium


  Support ovary
• Mesorchium


  Support testis
• Divisions of the coelom

  1. Divided into two longitudinal halves by the dorsal and ventral mesenteries

  2. Divided into a small anterior pericardial cavity and a large posterior pleuroperitoneal cavity by the transverse septum

  3. In some reptiles, birds and mammals the pleuroperitoneal cavity is further divided by the oblique septum or diaphragm
• Pericardial cavity


  Small anterior compartment containing only the heart
• Pleuroperitoneal cavity


  Very large posterior compartment containing all other viscera
• Pleuroperitoneal or nephric fold


  Accomplishes the closure of transverse septum and other coelomic folds, descends from the dorsal body wall and fuses with the transverse septum
• Oblique septum


  Partition formed in birds
• Diaphragm


  Partition formed in mammals
• Portion of the pleuroperitoneal cavity anterior to the oblique septum or diaphragm


  Contains the lungs, consists of the two pleural cavities or pleural sacs, each enclosing a lung
• Peritoneal cavity


  Abdominal cavity, portion of the pleuroperitoneal cavity posterior to the oblique septum or diaphragm, encloses the greater part of the digestive tract and the urogenital system
• The division of the coelom in birds and mammals into four compartments (pericardial, two pleural, peritoneal) greatly increases the efficiency of lung respiration
• Archenteron


  Primitive intestine produced by invagination in the gastrula stage of the embryo, a simple tube of endoderm with one opening to the exterior
• Blastopore


  Opening to the exterior of the archenteron
• Adult digestive tract


  Consists of a thick-walled tube, composed of both endodermal and mesodermal elements, with the latter predominating
• Stomodaeum


  Anterior invagination that eventually forms the oral cavity
• Proctodaeum


  Posterior invagination that eventually forms the anal cavity
• Oral cavity


  Bounded by the jaws, palate, and buccal floor bearing the tongue
• Lips and cheeks


  Differentiate in higher forms
• Vestibule


  The space between lips and teeth
• Internal nares or choanae

  Open the nasal cavities into the roof of the oral cavity, tend to move backward and assume a far posterior position through the formation of the secondary palate
• Secondary palate


  Imperfectly formed in birds, reaches best development in mammals where it is continued backward by the soft palate to separate the food and respiratory passages
• Parts of the nasal apparatus in tetrapods

  • Tubular vestibulum
  • Central cavum nasi proprium
  • Nasopharyngeal duct
• Conchae


  Projections from the lateral wall into the cavum nasi propum
• Vomeronasal organ


  Jacobson's organ, an accessory nasal organ present in many tetrapods
• Palatal folds


  Help to form a passage from the choanae above the tongue to the pharynx to aid the passage of air