4.8 Soft Tissue

4.8.1 Soft Tissue

  • There are 4 types of soft tissue of interest to this course:
    • Muscle
    • Tendon
    • Ligament
    • Cartilage
  • We will introduce each of these in this lecture, and each will get substantial treatment (lecture+)

4.8.2 Muscle

Anatomist90 CCSA3.0 Anatomist90 CCSA3.0

  • Approximately 700 muscles in the human body
  • Three broad classifications
    • Skeletal
    • Cardiac
    • Smooth and visceral (internal to the body cavity)
  • Also can be classified as
    • Voluntary Striated (skeletal)
    • Involuntary Striated (cardiac)
    • Involuntary (smooth)

4.8.3 Muscle groups

@Gray1918

  • In this course, we are principally concerned with skeletal muscles
  • These muscles predominately act in groups that have a common insertion point on a bone
  • The groups act in concert to provide motion and stability… we will most often consider the group as a whole
    • ie the quadriceps is made up of four muscles

Unlabelled Image Missing9

  • Muscles groups contract to activate, position, and stabilize the body
  • They work in concert with each other, co-contraction of agonist and antagonist muscles produces joint control and stability
    • Example, the hamstring and quadriceps simultaneously contract by variable amounts to stability the knee joint in flexion/extension

Unlabelled Image Missing

  • Muscle contraction leads to forces, forces leads to strains in the muscle
    • Thus, the muscle is also a spring which stores energy
    • This is important for energy management within the body
  • Note the distinction between strain (injury) and strain (elasticity)

4.8.4 Tendons and ligaments

@Bartel2006 CCSA4.0 Original source

  • Tendons connect muscle to bone
  • Ligaments connect bone to bone
  • Both can be modeled as simple cables, however, each has tissue bundles at multiple length scales (ie like fibers that join to form a strand, strands join to form a rope)
  • When stretched, they deform and have spring like qualities as well

4.8.5 Articular cartilage

CCSA3.0 Diagrammatic section of a diarthrodial joint. @Gray1918

  • Complex set of tissues consisting of fibrous matrix, water, large molecules, and other elements
  • 2-4 mm thick… thickness changes with age
  • Note: bursae - Tiny, slippery sacs of fluid which facilitate this gliding motion by providing a thin cushion and reducing friction between surfaces.10

4.8.6

Elbow joint - deep dissection (anterior view, human cadaver) Anatomist90 CCSA3.0

  • No nerves or blood supply in cartilage
    • Difficult to detect damage
    • Does not heal
  • Level of detail in the engineering model depends on the desired outcome

  1. Public domain https://www.needpix.com/photo/929804/muscles-skeleton-half-body↩︎

  2. https://www.arthritis-health.com/types/bursitis/what-bursa↩︎