Adaptation in Bone Structure

The force exerted per unit area within a material.

A type of stress where the force is perpendicular to the surface, either pulling the material apart (tensile) or pushing it together (compressive).

A type of stress where the force is parallel to the surface, causing the material to slide or shear.

A long, thin object with uniform material and cross-section, often used in stress analysis.

The imaginary surface across which we measure stress.

A force that acts on a material to stretch or compress it.

The state where all forces are balanced and the system is not moving.

The ability of a material to deform and return to its original shape after stress is removed.

The probability of resorption (bone breakdown) is the same across all bone surfaces and not influenced by mechanical strain.

The probability of resorption varies based on mechanical strain, with low strain areas (disuse) having higher resorption rates and high strain areas having lower rates.

Osteocytes, bone cells, are believed to send signals related to mechanical disuse, potentially triggering resorption in those areas.

Both increased exercise intensity and the presence of resorption cavities (bone breakdown sites) stimulate bone formation.

Reduced loading on bones mostly leads to bone loss through resorption.

A computational model used to simulate bone adaptation under different strain conditions.

The balance between bone resorption and bone formation leads to a stable bone mass and architecture.

The model suggests that strain-regulated resorption leads to faster development of a homeostatic architecture.

A special cell found deep inside bone, which acts like a sensor, detecting changes in bone strain (how much the bone bends or stretches).

A thin, tube-like passageway connecting osteocytes to each other and to the bone surface. The canalicular network acts like a communication network to transmit strain signals.

A cell type that builds new bone tissue by forming a mineralized matrix around itself. Osteoblasts respond to signals from osteocytes.

A cell type that dissolves bone, breaking it down. Osteoclasts are involved in remodeling bone.

The process of bone formation, where osteoblasts create new bone tissue.

The constant cycle of bone breakdown (resorption) by osteoclasts and bone formation (modeling) by osteoblasts. Remodeling keeps bone strong and healthy.

A small indentation or cavity on the surface of a bone. This is where osteoclasts attach and start bone resorption.

A type of cell covering the surface of bone. Lining cells communicate with osteocytes and contribute to bone remodeling.

A direction where the stress vector is parallel to one of the axes. It's found by solving the equation (s - spI)n = 0, where s is the stress tensor, sp is a scalar, I is the identity matrix, and n is a unit vector.

The scalars obtained by solving the characteristic equation of the stress tensor. They represent the normal stresses in the principal stress directions.

Quantities calculated from the stress tensor that remain constant regardless of the coordinate system rotation. They provide information about the overall nature of the stress state.

The trace (sum of diagonal elements) of the stress matrix. It measures the tendency of the stress state to induce hydrostatic dilation or compression.

A stress state characterized by a vanishing trace of the stress matrix. It implies that the stresses act purely in shear without any hydrostatic component.

Finding the angle at which the shear stress disappears. It's done by setting the shear stress component in the rotated coordinate system to zero.

The expression for the shear stress in the rotated coordinate system, obtained by transformation of the stress tensor.

The shear stress component in the rotated coordinate system is set to zero to find the angle at which the normal stress is maximum. This angle corresponds to the principal stress direction.

A type of biomaterial that is designed to break down over time, eventually being replaced by the body's natural tissue.

A common procedure used to measure the stiffness or elasticity of a material.

The ability of a material to withstand compressive forces (pushing forces) without breaking or deforming.

A surgical procedure that involves creating a small hole in a bone.

A method used to measure the density and structure of bone using X-rays.

The amount of bone resorbed per unit volume per day (roc) remains constant under normal conditions. This means bone breakdown is consistent in healthy individuals. Think of it like a steady pace on a treadmill.

Osteocytes are bone cells that sense mechanical forces. They act like tiny sensors that tell the body whether bone needs to adapt. Like an earthquake detector!

Homeostatic bone mass is the balance between bone formation and resorption, leading to a stable bone structure. This is like a seesaw in equilibrium, where each side is equal.

Mechanical loading is the force applied to bone. It can be from everyday activities like walking, running, or even lifting weights. Think of the pressure you feel on bones when you exercise.

Tissue engineering aims to create living tissues in a lab. It combines cells, biomaterials, and engineering principles to repair damaged tissues. Imagine building a new part for a broken machine.

Osteoclasts are bone-resorbing cells. They break down old bone tissue for remodeling. Think of them as the demolition crew in bone renovation.

The study found that increasing osteoclast activation frequency (roc) can lead to bone loss, particularly in postmenopausal women. This is similar to the bone density decline observed in women after menopause.