Kinesiology: JOINT-STRUCTURE-AND-FUNCTION-ppt

Joint

Joint

It connects two or more components of a structure.

Connective tissue

It is a type of tissue that provides support and connects different parts of the body.

Extracellular matrix

It is a complex network of proteins and other molecules that surrounds cells in connective tissue.

Collagen

It is the most abundant protein in the human body and is a major component of the extracellular matrix.

Fibroblast

These are cells that produce the extracellular matrix in connective tissue.

Chondrocyte

These are cells found in cartilage that produce and maintain the extracellular matrix.

Osteocyte

These are mature bone cells that maintain the extracellular matrix of bone tissue.

Elastin

It is a protein that provides elasticity to tissues, such as skin and blood vessels.

Glycosaminoglycans (GAG)

These are long chains of repeating disaccharide units that are attached to proteins in the extracellular matrix.

Ligament

Bands of connective tissue that connect bones to other bones, providing stability to joints.

Ligaments

Connective tissues that attach bone to bone.

Tendons

Connective tissues that attach muscle to bone.

Enthesis

The point of attachment of ligaments and tendons to bone.

Fibrocartilage

Cartilage that forms the attachment between tendons/ligaments and bone.

Fibrous attachment

Attachment of tendons/ligaments to bone where collagen fibers blend into the periosteum of the bone.

Sharpey's fibers

Fibers that attach the periosteum of the bone to the underlying cortical bone.

Endotendon

Groups of tendon fibers enclosed by a loose connective tissue sheath.

Peritendon

The combination of epitenon and paratenon.

Tenosynovium

A synovium-filled sheath that can form around the peritendon in areas of high friction.

Elastic cartilage

Cartilage that contains more elastin and is found in ears and the epiglottis.

Hyaline cartilage

Cartilage that forms a thin covering at the ends of bones in synovial joints and provides a smooth, low friction surface.

Articular cartilage

Another term for hyaline cartilage.

Tidemark

The boundary between calcified and uncalcified parts of the enthesis.

Myotendinous junction

The attachment of a tendon to muscle.

Endochondral ossification

The replacement of the calcified layer of articular cartilage with bone.

Chondrocytes

The cells found in cartilage.

Osmotic swelling pressure

The pressure created by the attraction of water to proteoglycans in cartilage.

Equilibrium

The balance between swelling pressure and load on the joint, which stops deformation of cartilage.

Synovial fluid

The fluid that nourishes chondrocytes in hyaline cartilage.

Extracellular matrix

The non-cellular component of cartilage that contains collagen fibers, proteoglycans, and water.

Degeneration

The breakdown or deterioration of cartilage, which can lead to conditions like osteoarthritis.

Bone

The hardest connective tissue in the body, composed of organic material for flexibility and tensile strength, and inorganic material for compressive strength.

Fibroblasts

Bone cells that produce type 1 collagen and other extracellular matrix components.

Osteoblasts

The primary bone forming cells responsible for synthesis of bone and deposition and mineralization.

Osteoclasts

Bone cells responsible for bone resorption.

Compact bone

The outer dense layer of bone.

Cancellous bone

The inner spongy bone with thin plates called trabeculae.

Periosteum

The fibrous layer that covers the entire surface of the bone except the articular surface.

Woven bone

Young bone with irregularly arranged collagen fibers.

Lamellar bone

Adult bone with an organized extracellular matrix framework.

Wolff's Law

The change in bone shape to match function in response to new forces.

Osteoporosis

A condition where there is an imbalance between bone synthesis and resorption, resulting in decreased bone mineral density and increased susceptibility to fracture.

Isotropic materials

Materials that display the same mechanical behavior regardless of the direction of applied forces.

Anisotropic materials

Heterogeneous connective tissues that behave differently depending on the size and direction of applied forces.

SAID principle

The ability of connective tissues to respond to load alterations.

Load

The force applied to a structure.

Deformation

The change in shape or size of a structure due to applied forces.

Elasticity

The ability of a material to return to its original shape after deformation.

Plasticity

The ability of a material to undergo permanent deformation without breaking.

Ultimate strength

The maximum load a material can withstand before failure.

Stiffness

The resistance of a material to deformation under applied forces.

Stress

The force per unit area of a material.

Strain

The percentage change in length or cross section of a structure or material.

Ultimate stress

The stress just before a material fails.

Ultimate strain

The strain at the point of failure.

Tensile stress

Stress caused by forces pulling in opposite directions, resulting in elongation.

Tensile strain

Strain caused by elongation of a structure or material.

Compressive stress

Stress caused by forces pushing towards each other, resulting in compression.

Compressive strain

Strain caused by compression of a structure or material.

Shear loading

Forces applied parallel to each other but in opposite directions, resulting in shear stress and strain.

Torsional loading

Forces applied perpendicular to the long axis of a structure, resulting in torsional stress.

Bending forces

Forces applied to a structure that create both tensile and compressive stress and strain.

Stress-strain curve

A graphical representation that shows the relationship between stress (force per unit area) and strain (deformation) of a material. It is used to compare the strength properties of different materials or to compare the same tissue under different conditions.

Elastic materials

Materials that can deform under stress but return to their original shape when the stress is removed. The stress-strain curve for these materials is flatter.

Stiff materials

Materials that have a high resistance to deformation under stress. The stress-strain curve for these materials is steeper.

Brittle material

A material that is strong but has little strain for a high stress. It fractures suddenly with little or no plastic deformation.

Ductile material

A material that can undergo plastic deformation after the elastic region. It has a section where "necking" occurs, which is a permanent deformation.

Plastic material

A material that has a very small elastic region and undergoes permanent deformation in the plastic region.

Young's modulus

Also known as the modulus of elasticity, it is a measure of a material's stiffness or resistance to external loads. It is represented by the slope of the linear portion of the stress-strain curve.

Load deformation curve

Each material has its own stress and strain curve, which represents its unique behavior under load and deformation.

Toe region

The first region of the stress-strain curve where very little force is required to deform the tissue. It is characterized by minimal stress and large deformation.

Elastic region

The second portion of the stress-strain curve where elongation has a linear relationship with stress. Additional force creates an equal stress and strain in the tissue.

Plastic region

The third region of the stress-strain curve where the failure of collagen fibers begins. The tissue no longer returns to its original length after the force is removed.

Rupture

Failure that occurs in the middle of the structure through disruption of connective tissue fibers.

Avulsion

Failure that occurs at the bony attachment of the ligament or tendon.

Fracture

Failure that occurs within the bony tissue.

Viscoelasticity

The property of a material that exhibits both elastic and viscous behavior. It is influenced by factors such as collagen and elastin content, length change, and applied load.

Viscosity

A material's resistance to flow. It reduces as the temperature increases or with slow loading, and increases with pressure or rapid loading.

Creep

A time-dependent deformation that occurs under a constant load and length change.

Stress relaxation

When a tissue is stretched to a fixed length and held there, the force needed to maintain this length decreases with time.

Hysteresis

The energy dissipated by elongation and the heat released during loading and unloading of a material.

Strain rate sensitivity

The sensitivity of a material's response to the rate at which it is strained. Fast strain rates result in low strain, while slow strain rates result in high strain.

Cortical bone

A type of bone that is stiffer than cancellous bone. It resists compressive stress more than tensile stress.

Cancellous bone

A type of bone that is less stiff than cortical bone. It has a higher percentage of void spaces and is more resistant to compressive stress.

Tendons

Connective tissues that connect muscles to bones. They exhibit creep when subjected to tensile loading.

Ligaments

Connective tissues that connect bones to other bones. They can withstand forces in all directions without being damaged but are less resistant to tensile stress.

Cartilage

A type of connective tissue that forms the smooth surface of joints. It resists applied load and experiences swelling pressure and friction due to fluid flow.

Compression

The reduction in volume of cartilage that increases pressure and causes fluid to flow out.

Frictional resistance

The resistance to fluid flow within tissues caused by fluid flow through the extracellular matrix.

Hoop stresses

Stresses created when compressed proteoglycans and water push against collagen fibers in cartilage.

Toe region

The region in cartilage, ligaments, and tendons where frictional drag or straightening of collagen fibers occurs.

Shear stress

Stress that develops between the calcified layer and subchondral bone in cartilage.

Joint capsule

The structure that surrounds a joint and provides stability.

Synovial fluid

Fluid that covers the inner layer of the joint capsule and articular cartilage, lubricates the joint, reduces friction, and nourishes the cartilage.

Viscosity

The resistance of a substance to shear load, which can be affected by factors such as rate of movement and temperature.

Lubrication

The process of reducing friction between joint surfaces.

Hydrostatic lubrication

Lubrication where load-bearing surfaces are held apart by a film of lubricant maintained under pressure.

Hydrodynamic lubrication

Lubrication where a wedge of fluid is created when non-parallel opposing forces slide on each other.

Squeeze film lubrication

Lubrication where pressure is created in the fluid film by the movement of articular surfaces that are perpendicular to each other.

Elastohydrodynamic lubrication

Lubrication where the fluid film is maintained at a certain thickness as the elastic cartilage deforms slightly to maintain an adequate layer of fluid between the joint surfaces.