ZOOL FINALS

• Skeletons


  are supportive systems that provide protection, support, and a place for muscle attachment.
• Hydrostatic Skeleton


  muscles in the body wall develop force by contracting against incompressible coelomic fluids.
• Alternate


  _____________ contractions of circular and longitudinal muscles of the body wall enable a worm to move forward.
• Muscular hydrostats


  __________ work because they are composed of incompressible tissues.
• Complex


  ___________ movements are a result of complex arrangements of muscles.
• Muscular Hydrostat


  Elephant's trunk, mammal & reptile tongues, cephalopod
• Rigid Skeletons


  Provide anchor points for pairs of opposing muscles. ● Provides protection & support
• Exoskeleton


  found in molluscs & arthropods and some other invertebrates.
• Endoskeleton


  found in echinoderms, chordates, and some cnidarians.
• Bone and cartilage


  The vertebrate endoskeleton is composed of _________ and ___________
• Bone


  provides support, protection, and serves as a reservoir for calcium and phosphorous.
• Notochord


  is a supportive rod found in protochordates and developing vertebrates.

  Derived from mesoderm.
• True


  (True or False) Except in jawless vertebrates, the notochord is replaced by the backbone.
• Jawless fishes and elasmobranchs

  have cartilaginous skeletons - a derived feature since their ancestors had bony skeletons.
• True


  (True or False) Most vertebrates have bony skeletons, with some cartilaginous parts.
• Cartilage


  is a soft, pliable tissue that resists compression and is variable in form.
• Hyaline cartilage


  has a clear, glassy appearance with chondrocytes surrounded by a matrix.

  No blood vessels.
• Cartilage


  is often found at articulating surfaces of many bone joints, and as supporting rings of the passageways in the respiratory system.
• ● Radula of gastropods

  ● Lophophore of brachiopods


  Cartilage similar to hyaline cartilage is found in many invertebrates
• Bone


  is highly vascular living tissue that contains significant deposits of inorganic calcium salts.
• Endochondral (replacement) bone


  develops from another form of connective tissue - usually cartilage.
• Intramembranous bone


  develops directly from sheets of embryonic cells.
• True; bone can vary in density


  (True or False) Bone cannot vary in density
• Spongy bone


  consists of open, interlacing framework of bony tissue, oriented to give strength.
• Compact bone


  is dense - the open framework of spongy bone has been filled in by additional calcium salts.
• Osteon


  Compact bone is composed of a calcified bone matrix arranged in sets of concentric rings - _________
• Lacunae


  Between the rings are _________ (cavities) filled with osteocytes (bone cells) connected by tiny passageways that distribute nutrients.
• False; bone is a dynamic tissue


  (True or false) Bone is not a dynamic tissue.
• Osteoclasts


  bone resorbing cells
• Osteoblasts


  bone building cells
• PTH (Parathyroid Hormone)


  Hormones for resorption
• Calcitonin


  Hormones for deposition
• Parathyroid Hormone (PTH) and Calcitonin


  Two hormones responsible for maintaining a constant calcium level in the blood
• Axial Skeleton


  includes the skull, vertebral column, ribs, and sternum.
• Appendicular Skeleton


  includes the limbs and pectoral and pelvic girdles.
• True


  (True or False) Over time, the number of skull bones has been reduced from as many as 180 in some early fishes to 35 or fewer in mammals.
• Vertebral column


  serves as the main stiffening axis.
• False; Most vertebrates have paired appendages


  (True or False) Most vertebrates does not have paired appendages
• pectoral and pelvic girdles.


  Pectoral and pelvic fins in fishes supported by the __________ and __________
• pentadactyl


  Tetrapods have two pairs of ________ limbs (although they may be highly modified through bone loss or fusion).