Livestock Skeletal Systems

  • The skeletal system of mammal is composed of bones, cartilage, teeth, and joints.


horse_skeleton.png
Skeleton of Horse

Formation of Bone
  • Cartilage is a tough connective tissue that is flexible and elastic.
  • Bones are composed of calcium compounds and a gelatin-like protein called ossein.
  • Bones are living structures containing blood and lymph vessels and nerve fibers.
  • Bones grow and repair themselves if damaged.
  • Some bones have a hollow center that is filled with marrow.
  • Bone marrow may be red, yellow, white, or gelatinous.
  • The type of marrow found in bones is to some degree a function of the age of the animal.
  • Red marrow is the type that forms blood cells and may be the only type found in animals with short life spans.
  • The other types of marrow tend to form in animals with life spans greater than ten years.
Functions of the Skeletal System
  • The functions of the skeletal system are to provide form, protection, support, and strength for the body.
  • With the muscles attached, the bones of the skeleton act as levers permitting the animals to move.
  • The bones store minerals and the bone marrow produces blood cells.
Types of Skeletal Systems
  • Skeletal systems may be rigid or hydraulic.
  • There are two types of rigid systems: endoskeleton and exoskeleton.
  • The endoskeleton is found on the inside of the body.
  • The exoskeleton is typically a hard shell on the outside of the body.
Kinds of Bones
  • The two kinds of bone material, cancellous and compact, are based on structure.
  • Bones may be divided into four classifications based on shape: long, short, flat, and irregular.
  • Long bones: humerus, radius, ulna, metacarpals, first and second phalanx, femur, tibia, metatarsus
  • Short bones: digital sesamoid bones, patella, tarsus
  • Irregular: vertebra
Parts of the Skeletal System
  • The three components of the skeletal system are the axial skeleton, pectoral limb, and pelvic limb.
  • The skull, vertebral column, and rib cage are the main parts of the axial skeleton.
  • The pectoral limbs are the front legs of the animal and the pelvic limbs are the hind legs.
Joints of the Skeleton
  • Three types of joints are found in the skeleton of an animal: synarthroses or fibrous joints; amphiarthroses or cartilaginous joints; and diarthroses or synovial joints.
  • Synarthroses or fibrous joints generally do not permit any type of movement.
  • The bones of the skull are an example of this joint.
  • The vertebra are joined by the amphiarthroses joints.
  • These joints consist of discs of a fibrous cartilage that separates and cushions the vertebrae, allowing very limited movement.

cowskel.jpg
Skeleton of cow

  • Avian bones tend to be thinner, harder, and more brittle than mammalian bones.
  • Long bones have more length than width and are generally cylindrical in shape.


illu_long_bone.jpg
Parts of Bone


Study Questions
1. What are the main functions of the skeletal system?
2. What are the three components and the major parts that comprise the skeletal system?
3. Describe the kinds of bones normally found in the mammalian skeletal system.
4. Name several functions of bones.