Bio Ch. 45 Animal Movement

• Hydrostatic skeletons

  use hydrostatic pressure of enclosed body fluids or soft tissue to support the body
• Endoskeletons

  have rigid structures inside the body
• Exoskeletons

  have rigid structures on the outside of the body
• hydrostatic skeletons structure

  a body wall surrounded by a fluid or tissue under compression; helps soft-bodied animals maintain posture, re-extend muscles, and transfer muscle forces to the environment.
• Vertebrate skeletons are composed of 3 elements:

  Bones, Cartilage, ligaments
• bones

  have cells in a hard extracellular matrix; interact at articulations or joints
• cartilage

  has cells scattered in a gelatinous matrix of polysaccharides and protein fibers
• ligaments

  bands of fibrous connective tissue that binds bones to other bones
• tendons

  bands of fibrous connective tissue; how bones attach to skeletal muscles
• Connective tissue

  makes up bone, cartilage, tendons, and ligaments
• muscle tissue

  enables voluntary movements
• nervous tissue

  senses body position and controls muscles that determine bone positions
• axial skeleton

  surrounds central axis of the body
• apprendicular skeleton

  consists of appendages and bones that surround them.
• skull

  protects brain and sense organs
• ribs

  protect the heart and lungs
• vertebral column

  protect spinal cord
• pectoral girdle


  connects forelimbs to axial skeleton; shoulders
• pelvic girdle

  attaches hind limbs to axial skeleton
• bone functions

  provide movement; supply calcium and phosphorus to the body; cells form at the marrow inside bones
• bone structure

  lightweight and strong; porous rather than solid; consists of mineralized extracellular matrix; consists of collagen and minerals; collagen add flexibility, while minerals add hardness and rigidity
• Bone


  an organ of the skeletal system
• Red bone marrow

  soft, spongy tissue that is a nursery for blood cells and platelets
• yellow bone marrow


  fatty tissue that occupies the marrow cavity of adult bones
• compact bone tissue


  hard, dense bone tissue, with canals for blood vessels and nerves
• spongy bone tissue

  light, porous bone tissue with spaces filled with marrow, blood vessels, and nerves
• cartilage


  smooth, rubbery connective tissue that absorbs shocks and reduces friction at joints
• tendon


  connective tissue that attaches a bone to a muscle, stabilizing a movable joint
• ligament


  connective tissue that attaches a bone to another bone, stabilizing a movable joint
• joint


  the area where two bones meet, allowing for movement
• tendons


  tough bands of connective tissue that attach bone to muscle
• Ligaments


  tough bands of connective tissue that attach bone to bone
• bones help regulate...

  calcium homeostasis
• calcium

  vital for muscle contraction, blood clotting, and activity of enzymes
• The muscular system


  provides motion; muscle cells contract when stimulated by nervous system; skeleton adds a firm supporting structure that muscles pull against.
• Connective tissue


  makes up tendons that attach muscles to bones
• muscle tissue function

  connects to bones and soft tissue, enabling movement of body parts
• nervous tissue


  senses body position and controls muscles
• muscle fibers


  make up a muscle; each fiber is an individual muscle cell with a highly specialized structure
• thick filament

  myosin