BI 231 - Chapter 9.1

STUDY GUIDE - Chapter 9-JOINTS: Sections 9.1-9.3; emphasis on Section 9.2

Section 9.1

  1. explain what joints are, how they are named, and what functions they serve;

    1. Any point where 2 bones meet is a joint – study of joints = arthrology, musculoskeletal movement = kinesiology

    2. Four subclasses: Bony, Fibrous, Cartilaginous, and Synovial

  2. name and describe the four major categories of joints;

    1. Bony Joints aka Synostosis

      1. immobile joint formed when 2 bones ossify and become a single bone.

      2. Can for by ossification of fibrous or cartilaginous joints

    2. Fibrous Joints aka Synarthrosis

      1. Point which adjacent bones are bound by collagen fibers that come from one bone, cross the space between them, and penetrate another bone.

      2. Three types: Sutures, Gomphoses, and Syndesmoses

        • Sutures – immobile/slightly mobile fibrous joints that solely bind the bones of the skull to each other, no where else; 3 classes: Serrate, Lap, and Plane sutures

          1. Serrate sutures – wavy lines along where adjoining bones firmly interlock by serrated margins (like a puzzle); examples = coronal, sagittal, and lambdoid sutures that border the parietal bones

          2. Lap (squamous) sutures – where two bones have overlapping beveled edges; example = squamous suture where temporal bone meets the sphenoid/parietal bones.

          3. Plane (butt) sutures – where two bones have straight nonoverlapping edges; example = intermaxillary suture in the roof of mouth

        • Gomphoses – the attachment of a tooth to socket is this and is held by fibrous periodontal ligament; like a nail hammered into wood

        • Syndesmoses – fibrous joint where tow bones are bound by long collagenous fibers; the separation between the bones/length of fiber gives these more mobility; example = between shafts of radius/ulna, distal ends of tibia/fibula

    3. Cartilaginous Joints aka Amphiarthrosis - Two bones linked by cartilage; Two types: Synchondroses & Symphyses

      1. Synchondrosis – joint joined by hyaline cartilage; examples = temp joint between epiphysis and diaphysis of a long bone in a child & first rib to the sternum by a hyaline costal cartilage

      2. Symphyses – two bones joined by fibrocartilage; examples = pubic symphysis where right & left pubic bones are joined by cartilaginous interpubic disc, or two vertebrae are united by intervertebral disc.

    4. Synovial (see next section)

  3. describe the three types of fibrous joints and give an example of each;

    1. See above

  4. distinguish between the three types of sutures;

    1. See above

  5. describe the two types of cartilaginous joints and give an example of each; and

  6. explain, with examples, why some joints change categories as a person ages.