BMED 322 - Lec 08 Bone Tissue

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Which of the following is NOT a primary function of bone in the human body?

Synthesizing vitamin D (correct)
Providing rigid kinematic links
Facilitating muscle action
Protecting internal organs

The femur is the smallest and lightest bone in the human skeleton.

False (B)

What percentage of bone weight is typically attributed to water content?

10%

The organic extracellular matrix of bone is primarily composed of type I ______ fibers.

collagen Signup and view all the answers

Match the bone cell types with their primary function:

Osteocytes = Mature bone cells that maintain bone tissue Osteoblasts = Bone-forming cells responsible for bone growth and repair Osteoclasts = Cells that break down bone tissue, playing a role in bone remodeling Signup and view all the answers

Which of the following structures is NOT found within an osteon?

Volkmann's canal leading into another osteon (C) Signup and view all the answers

Lamellar bone is primarily found in embryos and newborns.

False (B) Signup and view all the answers

What type of bone has a dense structure and forms the outer shell of bones?

Cortical bone Signup and view all the answers

Trabecular bone is composed of thin rods or plates called ______, forming a loose mesh structure.

trabeculae Signup and view all the answers

Match the bone types with their structural properties:

Cortical Bone = Dense, tightly packed structure providing strength and protection Trabecular Bone = Loose mesh-like structure providing structural support and flexibility Signup and view all the answers

Which of the following best describes 'toughness' in the context of bone biomechanics?

The energy a material can store before failing (B) Signup and view all the answers

A steeper slope in the elastic region of a stress-strain curve indicates a less stiff material.

False (B) Signup and view all the answers

What are the two main phases that comprise bone as a biphasic material?

Mineral phase and collagen phase Signup and view all the answers

Collagen acts as an arrestor of ______ in bone, improving fracture toughness.

cracks Signup and view all the answers

Match the terms to their descriptions:

Yield Point = Point past which permanent deformation of the bone sample occurred Ultimate Failure Point = The point past which failure of the sample occurred Signup and view all the answers

What does the area under the stress-strain curve represent?

Modulus of toughness (D) Signup and view all the answers

If a load is applied within the elastic range of a material, permanent deformation will occur.

False (B) Signup and view all the answers

What type of machine is used to obtain stress and strain values for bone tissue by loading a standardized specimen to failure?

Instron Machine Signup and view all the answers

Yielding in bone under tension is caused by debonding of the osteons at the cement lines and ______.

microfracture Signup and view all the answers

Match the following terms with their associated properties:

Brittle Material = Fractures with little to no plastic deformation Ductile Material = Undergoes significant plastic deformation before failure Signup and view all the answers

Which of the following is TRUE regarding the mechanical properties of cortical and trabecular bone?

Cortical bone is stiffer than trabecular bone. (B) Signup and view all the answers

Metal has a shorter plastic region than bone, indicating it deforms less before failure.

False (B) Signup and view all the answers

What is the primary reason that trabecular bone has a greater capacity for energy storage compared to cortical bone?

Porous structure Signup and view all the answers

Bone exhibits more brittle behavior at a ______ loading rate.

higher Signup and view all the answers

Indicate whether the properties:

Anisotropic = Properties vary depending on the direction of measurement Signup and view all the answers

Why is bone strongest and stiffest in the longitudinal direction?

Because the collagen fibers and hydroxyapatite crystals are primarily aligned in that direction (B) Signup and view all the answers

Longitudinal loading leads to lower strength and stiffness.

False (B) Signup and view all the answers

According to Wolff's Law, how does bone adapt to mechanical stress?

Bone remodels in response to habitual mechanical stress Signup and view all the answers

Forces that pull bone apart, potentially leading to fractures, are known as ______ forces.

tension Signup and view all the answers

Match the loading type with its description:

Tension = Forces pull bone apart, can lead to fractures Compression = Forces push bone together, bone resists well. Shear = Forces slide layers of bone past each other, weaker Signup and view all the answers

In which type of bone is a tensile fracture most common?

Trabecular bone (B) Signup and view all the answers

Maximum compressive stress occurs on a plane parallel to the applied load.

False (B) Signup and view all the answers

What type of stress is often seen in trabecular (cancellous) bone due to its weaker internal structure?

Shear stress Signup and view all the answers

In bending, the stresses and strains along the ______ axis are equal to zero.

neutral Signup and view all the answers

Match the type of bending with its description:

Three-point bending = Bending produced by three forces Four-point bending = It takes place when two force couples acting on a structure produce two equal moments Signup and view all the answers

Which of the following is true about the location of maximal stress in torsion?

Greatest away from the neural axis (B) Signup and view all the answers

The first crack that forms in a torsional fracture of bone is perpendicular to the neutral axis.

False (B) Signup and view all the answers

Due to the complexity of forces, bones are subjected to how many modes of loading at a time?

multiple Signup and view all the answers

During the stance phase of walking, ______ stresses occur as the body weight is shifted onto the supporting leg.

tensile Signup and view all the answers

What does a stride refer to?

stride refers to the distance covered in a single step cycle while walking or running (A) Signup and view all the answers

What is Bone?

Specialized connective tissue providing protection and support. Key functions: organ protection, rigid kinematic links, muscle attachment sites, facilitates movement.

How many bones in adult human body

The adult human body typically has 206 bones, but the number can vary slightly.

Smallest bone vs. Largest

Femur (thighbone) is the longest and strongest; stapes (stirrup) in middle ear is the smallest and lightest.