Bone Physiology

Question 1

What is bone?

Answer 1

Second hardest substance within an animals body (1st being the enamel layer of teeth) It is composed of cells embedded in a matrix (background)

Question 2

whats Matrix?

Answer 2

Is made up of collagen fibers embedded in a protein and polysacharides
-Hardens when deposits of calcium and phosphates are laid down.

Question 3

ossification

Answer 3

refers to the process by which new bone tissue is formed during skeletal development or bone healing. This process involves the deposition of minerals, primarily calcium and phosphate, into a matrix of collagen fibers, resulting in the hardening and strengthening of bone.

Question 4

Intramembranous bone formation

Answer 4

This type of ossification occurs within a connective tissue membrane. It is responsible for the formation of flat bones, such as those in the skull and certain parts of the face. During intramembranous ossification, mesenchymal cells differentiate into osteoblasts, which then secrete osteoid tissue that mineralizes to form bone.
occurs in certain skull bones, bone forms in the fibrous tissue membranes that cover the brain in the developing fetus.
⦿ Intramembranous ossification: The flat bones of the skull are formed. the osteoblasts lay down bone between two layers of fibrous connective tissue. there is no cartilage template.
Osteoblasts: Osteoblasts are the cells that form new bones and grow and heal existing bones.

Question 5

Endochondral Bone Formation

Answer 5

Endochondral ossification involves the replacement of cartilage with bone tissue. This process is responsible for the formation of most long bones in the body, as well as some irregular bones. During endochondral ossification, a cartilage model of the bone is first formed, which is gradually replaced by bone tissue as osteoblasts deposit minerals into the cartilage matrix.⦿ Primary growth center: bones develop in the diaphyses - cartilage rod -
⦿ Cartilage is removed as bone is created. Secondary growth centers: develop in the epithyses of bones.
⦿ Epiphyseal plates: cartilage is located between the diaphysis and the epiphysis of long bones, sites where new bone develops to allow long bones to lengthen.
⦿ Osteoblasts replace cartilage with bone on the diaphyseal surface of the plate, when the bone has reached its full size, the epiphyseal plates completely ossify.

Question 6

Osteoblasts

Answer 6

Osteoblasts are essential cells involved in bone formation and remodeling processes in the body. They originate from mesenchymal stem cells and are primarily found in the outer layer of bone tissue, known as the periosteum, as well as in the endosteum, which lines the inner surfaces of bones.

When bone formation is required, osteoblasts become activated and begin synthesizing and secreting osteoid, which is a matrix rich in collagen fibers. This osteoid serves as the framework or scaffold for new bone tissue formation. Over time, minerals such as calcium and phosphate are deposited onto the collagen fibers within the osteoid matrix, a process known as mineralization or calcification. This results in the hardening of the osteoid into mature bone tissue.

In addition to producing osteoid, osteoblasts also play a role in regulating the mineralization process by secreting proteins and enzymes that control the deposition of minerals. These cells are also involved in the synthesis and release of various growth factors and signaling molecules that influence the activity of other bone cells, such as osteoclasts (cells responsible for bone resorption) and osteocytes (mature bone cells embedded within the bone matrix).

As bone formation progresses, some osteoblasts become entrapped within the mineralized bone matrix and differentiate into osteocytes. These osteocytes maintain communication with neighboring cells and play a role in regulating bone metabolism and responding to mechanical stress.

Question 7

Fracture Types

Answer 7

Complete Fracture, Incomplete Fracture, Open Fracture (Compound Fracture), Closed Fracture, Transverse Fracture, Oblique Fracture, Spiral Fracture, Greenstick Fracture, Comminuted Fracture, Avulsion Fracture, Pathological Fracture, Impacted Fracture, Linear Fracture, Compression Fracture, Segmental Fracture, Hairline Fracture, Stress Fracture, Depressed Fracture, Displaced Fracture, Non-displaced Fracture, Fatigue Fracture, Tension Fracture, Shear Fracture, Torus Fracture (Buckle Fracture).

Question 8

Complete Fracture

Answer 8

• Cause: Typically caused by direct trauma, excessive force, or stress applied to the bone.
• Occurrence: Can happen in any bone of the body.
• Appearance: The bone is completely broken into two or more separate pieces.
• Healing Approach: Generally treated with immobilization, alignment, and stabilization through methods such as casting, splinting, or surgical fixation.

Question 9

Incomplete Fracture

Answer 9

• Cause: Similar to complete fractures, but the bone is partially broken.
• Occurrence: Any bone can experience an incomplete fracture.
• Appearance: The bone is partially broken, with some degree of continuity remaining.
• Healing Approach: Treatment involves immobilization and protection of the affected area to allow for bone remodeling and healing.

Question 10

Open Fracture (Compound Fracture)

Answer 10

• Cause: Trauma that causes the bone to penetrate through the skin, exposing it to the external environment.
• Occurrence: Can occur in any bone but is more common in long bones like the femur or humerus.
• Appearance: The broken bone protrudes through the skin, often accompanied by bleeding and potential contamination.
• Healing Approach: Immediate medical attention is required to clean and stabilize the wound, followed by fracture management and wound care to prevent infection.

Question 11

Closed Fracture

Answer 11

• Cause: Trauma without an open wound, where the bone breaks but does not penetrate the skin.
• Occurrence: Can happen in any bone.
• Appearance: The broken bone does not pierce through the skin.
• Healing Approach: Treatment involves immobilization and alignment of the bone to promote healing without the risk of infection.

Question 12

Transverse Fracture

Answer 12

• Cause: Direct force applied perpendicular to the long axis of the bone.
• Occurrence: Commonly seen in long bones like the femur, tibia, and humerus.
• Appearance: The fracture line runs straight across the bone.
• Healing Approach: Treatment typically involves realignment and stabilization with casts, splints, or surgical fixation if necessary.

Question 13

Oblique Fracture

Answer 13

• Cause: Force applied at an angle to the long axis of the bone.
• Occurrence: Can occur in any bone.
• Appearance: The fracture line runs diagonally across the bone.
• Healing Approach: Similar to transverse fractures, treatment involves realignment and stabilization.

Question 14

Spiral Fracture

Answer 14

• Cause: Twisting force applied to the bone.
• Occurrence: Often seen in long bones like the femur and tibia.
• Appearance: The fracture line spirals around the bone.
• Healing Approach: Requires careful realignment and stabilization to ensure proper healing and alignment.

Question 15

Greenstick Fracture

Answer 15

• Cause: Typically occurs in young animals with more flexible bones, resulting from bending rather than breaking.
• Occurrence: Common in long bones of young animals.
• Appearance: The bone is bent and partially broken, with one side intact and the other side fractured.
• Healing Approach: Often managed with immobilization and protection, allowing the bone to remodel and heal.

Question 16

Comminuted Fracture

Answer 16

• Cause: Severe force leading to the bone breaking into multiple fragments.
• Occurrence: Can occur in any bone.
• Appearance: Multiple bone fragments at the fracture site.
• Healing Approach: Surgical intervention may be necessary to align and stabilize the fragments, promoting proper healing.

Question 17

Avulsion Fracture

Answer 17

• Cause: Tendon or ligament pulls a small piece of bone away.
• Occurrence: Common in areas where tendons or ligaments attach to bones.
• Appearance: A small fragment of bone is separated at the attachment site.
• Healing Approach: Treatment involves immobilization and may require surgical intervention for reattachment.

Question 18

Pathological Fracture

Answer 18

• Cause: Fracture occurs in a bone weakened by an underlying disease or condition, such as bone cancer or osteoporosis.
• Occurrence: Can occur in any bone affected by the underlying pathology.
• Appearance: Fracture in a bone with pre-existing damage or weakness.
• Healing Approach: Management involves addressing the underlying condition and stabilizing the fracture.

Question 19

Impacted Fracture

Answer 19

• Cause: One fragment of bone is driven into another due to compression forces.
• Occurrence: Common in long bones.
• Appearance: The fractured ends are impacted into each other.
• Healing Approach: Stabilization and immobilization to allow the impacted fragments to unite.

Question 20

Linear Fracture

Answer 20

• Cause: Force applied parallel to the long axis of the bone.
• Occurrence: Can occur in any bone.
• Appearance: The fracture line runs parallel to the long axis of the bone.
• Healing Approach: Treatment involves realignment and stabilization.

Question 21

Compression Fracture

Answer 21

• Cause: Bone is crushed or compressed.
• Occurrence: Common in vertebrae.
• Appearance: The bone is compressed, often resulting in a wedge shape.
• Healing Approach: Immobilization and support to allow for vertebral healing and stabilization.
• Torus Fracture (Buckle Fracture):
• Cause: Compression force applied to the bone, causing it to buckle but not break completely.
• Occurrence: Commonly seen in the metaphyseal region of long bones, especially in children and young animals.
• Appearance: The bone buckles but remains intact.
• Healing Approach: Often heals spontaneously with immobilization and protection of the affected limb.

Question 22

Segmental Fracture

Answer 22

• Cause: High-energy trauma or direct force causing a bone to break into two distinct segments with an intermediate fragment.
• Occurrence: Can occur in any bone but often seen in long bones.
• Appearance: The bone breaks into two separate segments with an intermediate fragment.
• Healing Approach: Requires careful realignment and stabilization to ensure proper healing and alignment of all segments.

Question 23

Hairline Fracture

Answer 23

• Cause: Minor trauma or repetitive stress causing a small crack in the bone.
• Occurrence: Can occur in any bone.
• Appearance: A small, fine crack in the bone without significant displacement.
• Healing Approach: Often heals with rest and reduced activity, although sometimes requires immobilization or protection to prevent further damage.

Question 24

Stress Fracture

Answer 24

• Cause: Overuse or repetitive stress on the bone, leading to microscopic cracks.
• Occurrence: Commonly seen in athletes and working animals.
• Appearance: Small, hairline cracks in the bone due to repetitive stress.
• Healing Approach: Requires rest and modification of activities to allow for bone remodeling and healing.

Question 25

Depressed Fracture

Answer 25

• Cause: Direct trauma causing the bone to be pushed inward, creating a depression.
• Occurrence: Often seen in flat bones like the skull.
• Appearance: The bone is depressed or indented.
• Healing Approach: Treatment involves careful evaluation for associated injuries and may require surgical intervention to elevate the depressed bone fragment.

Question 26

Displaced Fracture

Answer 26

• Cause: Trauma causing the bone fragments to move out of alignment.
• Occurrence: Can occur in any bone.
• Appearance: Bone fragments are not in their normal alignment.
• Healing Approach: Requires reduction (realignment) of the fractured bone followed by stabilization to promote proper healing.

Question 27

Non-displaced Fracture

Answer 27

• Cause: Trauma causing a fracture without significant displacement of bone fragments.
• Occurrence: Can occur in any bone.
• Appearance: Bone fragments remain in their normal alignment.
• Healing Approach: Treatment usually involves immobilization and protection to allow for bone healing without the need for reduction.

Question 28

Fatigue Fracture

Answer 28

• Cause: Result of repetitive stress or loading on a bone over time, often seen in athletes or animals subjected to intense physical activity.
• Occurrence: Can occur in any bone.
• Appearance: Fracture caused by fatigue or weakening of bone due to repetitive stress.
• Healing Approach: Requires rest and modification of activities to allow for bone remodeling and healing.

Question 29

Tension Fracture

Answer 29

• Cause: Tensile forces applied to the bone, causing it to break apart.
• Occurrence: Can occur in any bone.
• Appearance: Bone breaks apart due to tensile forces.
• Healing Approach: Treatment involves realignment and stabilization to promote proper healing and alignment.

Question 30

Shear Fracture

Answer 30

• Cause: Occurs when forces are applied parallel to the surface of the bone, causing it to break along the plane of the force.
• Occurrence: Can occur in any bone.
• Appearance: Fracture occurs along a plane parallel to the surface of the bone.
• Healing Approach: Treatment involves realignment and stabilization to promote proper healing and alignment.

Question 31

Torus Fracture (Buckle Fracture)

Answer 31

• Cause: Compression force applied to the bone, causing it to buckle but not break completely.
• Occurrence: Commonly seen in the metaphyseal region of long bones, especially in children and young animals.
• Appearance: The bone buckles but remains intact.
• Healing Approach: Often heals spontaneously with immobilization and protection of the affected limb.

Question 32

Cancellous Bone:(Spongey bone)

Answer 32

Cancellous bone, also known as spongy bone or trabecular bone, is one of the two main types of bone tissue found in the human and animal skeletal systems, with the other being compact bone. Cancellous bone is characterized by its porous, honeycomb-like structure, which gives it a sponge-like appearance. This structure is composed of interconnected trabeculae or spicules, which form a network of thin bony plates and rods, creating spaces filled with bone marrow.

The trabeculae of cancellous bone are arranged along lines of stress within the bone, providing strength and support while minimizing weight. Despite its porous nature, cancellous bone is remarkably strong and resilient, capable of withstanding compressive forces and providing structural support to the skeleton.

Cancellous bone is found in the interior regions of bones, particularly in the epiphyses (ends) of long bones, as well as in the interior of flat bones such as the ribs, sternum, and vertebrae. It is also present in the interior of irregular bones and within the diploe of flat bones in the skull.

The spaces within cancellous bone are filled with bone marrow, a soft, gelatinous tissue that contains blood vessels, nerves, and hematopoietic stem cells responsible for the production of blood cells. Red bone marrow, which is involved in hematopoiesis (blood cell formation), is predominantly found within the spaces of cancellous bone in certain bones, such as the pelvis, ribs, vertebrae, and ends of long bones.

Cancellous bone plays several important roles in the skeletal system. It provides structural support and strength to bones while reducing their overall weight, which is particularly important for facilitating movement and agility in animals. Additionally, the presence of red bone marrow within cancellous bone supports the production of red and white blood cells and platelets, contributing to the body’s immune function and oxygen transport.

Question 33

Compact Bone

Answer 33

Compact bone, also known as cortical bone, is one of the two primary types of bone tissue found in the skeletal system, alongside cancellous (spongy) bone. It forms the dense outer layer of bones and provides strength, support, and protection to the skeleton.

Compact bone is characterized by its solid, dense structure, which is composed of tightly packed osteons, also known as Haversian systems. Each osteon consists of concentric layers of mineralized extracellular matrix called lamellae, surrounding a central canal known as the Haversian canal. The Haversian canal contains blood vessels, lymphatic vessels, and nerves that supply nutrients and oxygen to the bone tissue.
⦿ Strongest portion of the bone, makes up the shafts of long bones and the outside layer of all bones. Composed of heaversian systems that run lengthwise with the bone.

Question 34

Blood supply to bone

Answer 34

⦿ Volkmann canals: channels through the matrix that contain blood vessels.
⦿ Blood vessels in the volkmann canals join with blood vessels in the heaversion system.
⦿ Nutrient foramina: channels in many large bones that contain blood vessels, lymph vessels and nerves.
The blood supply to bones is essential for their health, growth, repair, and remodeling processes. Bones receive their blood supply through a network of blood vessels that penetrate their outer layers and penetrate into the interior bone tissue.

Nutrient Arteries: Large arteries, known as nutrient arteries, enter bones through small openings called nutrient foramina, which are located primarily in the shafts (diaphyses) of long bones. These arteries branch out within the bone, providing oxygen, nutrients, and other essential molecules to the bone cells (osteocytes), bone marrow, and other structures within the bone.

Metaphyseal and Epiphyseal Arteries: In addition to nutrient arteries, bones also receive blood supply from metaphyseal and epiphyseal arteries, which enter the bone near the ends (epiphyses) or adjacent to the growth plates (metaphyses) of long bones. These arteries supply blood to the growing regions of bones, including the growth plates (epiphyseal plates), where longitudinal bone growth occurs during development.

Periosteal and Endosteal Blood Vessels: The outer surface of bones (periosteum) is richly supplied with blood vessels, including arteries, veins, and capillaries. These blood vessels help nourish the outer layers of compact bone tissue and provide a route for blood vessels to enter the bone. Similarly, blood vessels from the surrounding bone marrow (endosteum) penetrate into the interior regions of bones, supplying nutrients and oxygen to the trabecular (cancellous) bone tissue and bone marrow.

Venous Drainage: Blood from the bone tissue is drained primarily by veins that accompany the nutrient arteries and exit the bone through the nutrient foramina. These veins eventually join larger venous channels, such as the venous sinuses within the bone marrow, which ultimately drain into systemic veins and return blood to the heart.

Question 35

Bone Marrow

Answer 35

-Fills in the spaces within the bones.
-Two types:
-yellow bone marrow: within the medullary cavity
-Red bone marrow: in the cancellous bone
Bone marrow is a soft, gelatinous tissue found in the cavities of bones, particularly in the long bones such as the femur (thigh bone), tibia (shin bone), and humerus (upper arm bone), as well as in flat bones like the sternum (breastbone), pelvis (hip bone), and skull. It is a vital component of the body’s hematopoietic system and plays essential roles in blood cell production, immune function, and bone metabolism.

There are two main types of bone marrow:

Red Bone Marrow (Hematopoietic Marrow): Red bone marrow is responsible for the production of blood cells through a process called hematopoiesis. It contains hematopoietic stem cells, which give rise to all types of blood cells, including red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes). Red bone marrow is richly vascularized and contains a network of blood vessels, supporting cells, and extracellular matrix.

Yellow Bone Marrow (Fatty Marrow): Yellow bone marrow consists mainly of adipose (fat) tissue and serves as a storage site for fat cells. It is found primarily in the medullary cavity (marrow cavity) of long bones in adult humans and mammals. While yellow bone marrow has a reduced capacity for hematopoiesis compared to red bone marrow, it contains mesenchymal stem cells (marrow stromal cells) that can differentiate into fat cells, cartilage cells, and bone-forming cells.

Bone marrow also contains supportive stromal cells, blood vessels, nerves, and extracellular matrix components that create a specialized microenvironment for hematopoiesis and stem cell maintenance. This microenvironment, known as the hematopoietic stem cell niche, plays a crucial role in regulating the function and behavior of hematopoietic stem cells and other cell types within the bone marrow.

Question 36

Yellow bone marrow (review)

Answer 36

ellow bone marrow, which predominates in the medullary cavity of long bones in adult humans and mammals, contains mesenchymal stem cells, also known as marrow stromal cells. These multipotent stem cells have the capacity to differentiate into various cell types, including adipocytes (fat cells), chondrocytes (cartilage cells), and osteoblasts (bone-forming cells).

Mesenchymal stem cells play important roles in tissue repair, regeneration, and homeostasis within the bone marrow microenvironment. They have the potential to differentiate into different cell lineages depending on the signals and stimuli they receive from their surrounding environment.

In addition to their role in producing fat cells, cartilage cells, and bone-forming cells, mesenchymal stem cells in the bone marrow microenvironment also contribute to immune regulation, hematopoiesis (blood cell formation), and the maintenance of the bone marrow niche.

Question 37

Fossa

Answer 37

depressed area on the surface of a bone.
A fossa, in the context of bone anatomy, refers to a shallow depression or concavity on the surface of a bone. Fossae serve various purposes, including providing attachment points for muscles, ligaments, or tendons, accommodating blood vessels and nerves, and articulating with adjacent bones to form joints.

Fossae can be found on various bones throughout the skeletal system, and their size, shape, and location vary depending on the specific bone and its function. Some examples of fossae include:

Glenoid fossa: A shallow, concave depression on the scapula (shoulder blade) that articulates with the head of the humerus to form the glenohumeral (shoulder) joint.

Mandibular fossa: A depression on the temporal bone of the skull that forms the temporomandibular joint (TMJ) with the mandibular condyle of the lower jaw (mandible).

Olecranon fossa: A hollowed-out area at the posterior aspect of the humerus where the olecranon process of the ulna fits during extension of the elbow joint.

Iliac fossa: A broad, concave surface on the inner aspect of the ilium (part of the pelvic bone) that provides attachment for muscles of the hip and lower back.

Subscapular fossa: A smooth, concave surface on the anterior aspect of the scapula that provides attachment for the subscapularis muscle.

Question 38

Foramen

Answer 38

A foramen, in the context of bone anatomy, refers to an opening or hole in a bone that allows for the passage of blood vessels, nerves, ligaments, or other structures. Foramina (plural form of foramen) are important features of bones as they provide pathways for vital structures to travel through and interact with other parts of the body.

Question 39

Facet

Answer 39

In anatomy, a facet refers to a small, smooth, flat, or slightly concave surface on a bone that articulates with another bone to form a joint. Facets are important for enabling smooth movement and stability within joints by providing surfaces for bones to glide or articulate against each other.

Question 40

Osteoclasts

Answer 40

Osteoclasts are cells that break down and resorb bone tissue, playing a crucial role in bone remodeling and maintenance of calcium homeostasis.

Question 41

Osteocytes

Answer 41

Osteocytes are mature bone cells embedded within the bone matrix, involved in maintaining bone tissue integrity and responding to mechanical stress.

Question 42

Osteogenesis

Answer 42

Osteogenesis refers to the process of bone formation, which involves the differentiation of mesenchymal stem cells into osteoblasts and the deposition of mineralized matrix to form new bone tissue.

Question 43

Osteolysis

Answer 43

Osteolysis is the process of bone resorption, during which osteoclasts break down bone tissue, releasing calcium and phosphate ions into the bloodstream.

Question 44

Bone remodeling

Answer 44

Bone remodeling is the continuous process of resorption and formation of bone tissue, mediated by osteoclasts and osteoblasts, respectively, to maintain bone structure and repair microdamage.

Question 44

Bone resorption

Answer 44

Bone resorption is the removal or breakdown of bone tissue by osteoclasts, releasing minerals and organic matrix components into the bloodstream for reuse.

Question 45

Bone deposition

Answer 45

Bone deposition is the process of new bone formation by osteoblasts, involving the synthesis and mineralization of bone matrix to increase bone mass and strength.

Question 46

Bone matrix

Answer 46

Bone matrix is the non-living, mineralized extracellular substance of bone tissue, composed primarily of collagen fibers and hydroxyapatite crystals, providing strength and structure to bones.

Question 47

Collagen

Answer 47

Collagen is a fibrous protein found in the bone matrix, providing tensile strength and flexibility to bone tissue.

Question 48

Hydroxyapatite

Answer 48

Hydroxyapatite is a mineral compound primarily composed of calcium and phosphate ions, forming the crystalline mineral phase of bone tissue, responsible for its hardness and rigidity.

Question 49

Trabeculae

Answer 49

Trabeculae are thin, branching bony plates or spicules found within cancellous (spongy) bone tissue, providing structural support and strength while reducing bone weight.

Question 50

Haversian canal

Answer 50

Haversian canals are microscopic channels within compact bone tissue that contain blood vessels, nerves, and lymphatic vessels, supplying nutrients and oxygen to bone cells.

Question 51

Lamellae

Answer 51

Lamellae are concentric layers of bone matrix surrounding the Haversian canals in compact bone tissue, providing strength and support to the bone structure.

Question 52

Lacunae

Answer 52

Lacunae are small cavities within the bone matrix that house osteocytes, allowing them to reside within the bone tissue and maintain contact with neighboring cells.

Question 53

Canalicul

Answer 53

Canaliculi are tiny channels that connect lacunae and allow osteocytes to communicate with each other and exchange nutrients and waste products within the bone tissue.

Question 54

Compact bone

Answer 54

Compact bone is dense, hard bone tissue found in the outer layer of bones, providing strength, protection, and support to the skeletal system.

Question 55

Endosteum

Answer 55

The endosteum is a thin layer of connective tissue lining the inner surfaces of bones, containing osteogenic cells and involved in bone remodeling and repair processes.

Question 56

Medullary cavity

Answer 56

The medullary cavity, also known as the marrow cavity, is the central cavity within long bones, containing yellow bone marrow and providing space for blood vessels and bone marrow.

Question 57

Hematopoietic stem cells

Answer 57

Hematopoietic stem cells are multipotent cells found in bone marrow that give rise to all types of blood cells, including red blood cells, white blood cells, and platelets.

Question 58

Marrow stromal cells

Answer 58

Marrow stromal cells, also known as mesenchymal stem cells, are multipotent cells found in bone marrow that can differentiate into various cell types, including osteoblasts, adipocytes, and chondrocytes.

Question 59

Bone remodeling unit

Answer 59

The bone remodeling unit is a functional unit of bone tissue composed of osteoclasts, osteoblasts, and bone lining cells, responsible for the continuous process of bone resorption and formation.

Question 60

Wolff’s law

Answer 60

Wolff’s law states that bone tissue adapts its structure and density in response to mechanical stresses and strains, leading to changes in bone shape and density to accommodate functional demands.

Question 61

Osteon

Answer 61

An osteon, also known as a Haversian system, is the fundamental structural unit of compact bone tissue, consisting of concentric lamellae surrounding a central Haversian canal.

Question 62

Volkmann’s canals

Answer 62

Volkmann’s canals are channels that traverse the compact bone tissue, connecting the Haversian canals and providing routes for blood vessels, nerves, and lymphatic vessels to travel through the bone.

Question 62

Interstitial lamellae

Answer 62

Interstitial lamellae are remnants of old osteons or fragments of bone matrix found between intact osteons within compact bone tissue, contributing to bone strength and stability.

Question 63

Perforating fibers

Answer 63

Perforating fibers, also known as Sharpey’s fibers, are collagen fibers that anchor the periosteum to the underlying bone tissue, providing structural support and stability to the bone surface.

Question 64

Bone mineral density (BMD)

Answer 64

Bone mineral density is a measure of the amount of mineralized bone tissue within a given volume of bone, reflecting bone strength and density, and serving as an indicator of bone health and risk of fracture.

Question 65

Bone turnover

Answer 65

Bone turnover refers to the continuous process of bone resorption by osteoclasts and bone formation by osteoblasts, maintaining bone homeostasis and remodeling bone tissue throughout life.

Question 66

Bone formation rate

Answer 66

Bone formation rate is the speed at which new bone tissue is synthesized and deposited by osteoblasts, influencing bone growth, repair, and remodeling processes.

Question 67

Bone mass

Answer 67

Bone mass, also known as bone quantity or bone volume, refers to the total amount of bone tissue present in the skeleton, reflecting bone size, density, and strength.

Question 68

Bone density

Answer 68

Bone density, also known as bone mineral density (BMD), is a measure of bone mass per unit volume, indicating bone strength and susceptibility to fractures.

Question 69

Bone strength

Answer 69

Bone strength refers to the ability of bone tissue to resist deformation, withstand mechanical forces, and maintain structural integrity, influenced by factors such as bone density, architecture, and mineralization.

Question 70

Bone fracture

Answer 70

A bone fracture is a partial or complete break in a bone resulting from excessive force or trauma, leading to disruption of bone tissue integrity and potential loss of function.

Question 71

Callus formation

Answer 71

Callus formation is the initial phase of fracture healing, characterized by the formation of a soft, provisional tissue bridge composed of fibroblasts, cartilage, and woven bone, stabilizing the fracture site and facilitating subsequent bone repair.

Question 72

Fracture healing

Answer 72

Fracture healing is the process by which broken bone tissue is repaired and restored to its original structure and function, involving inflammation, callus formation, and bone remodeling stages.

Question 73

Bone remodeling markers

Answer 73

Bone remodeling markers are biochemical indicators present in blood or urine that reflect the activity of osteoclasts and osteoblasts during bone remodeling, providing insight into bone turnover and metabolic bone diseases.

Question 74

Parathyroid hormone (PTH)

Answer 74

Parathyroid hormone is a hormone secreted by the parathyroid glands that regulates calcium and phosphate homeostasis by stimulating bone resorption, increasing calcium reabsorption in the kidneys, and activating vitamin D synthesis.

Question 75

Calcitonin

Answer 75

Calcitonin is a hormone secreted by the thyroid gland that regulates calcium homeostasis by inhibiting bone resorption, reducing calcium reabsorption in the kidneys, and promoting calcium deposition in bone tissue.

Question 76

Vitamin D

Answer 76

Vitamin D is a fat-soluble vitamin synthesized in the skin in response to sunlight exposure or obtained from dietary sources, essential for calcium absorption, bone mineralization, and regulation of bone metabolism.

Question 77

Osteoporosis

Answer 77

Osteoporosis is a systemic bone disorder characterized by low bone mass, deteriorated bone microarchitecture, and increased risk of fractures, commonly associated with aging, hormonal changes, and nutritional deficiencies.

Question 78

Osteomalacia

Answer 78

Osteomalacia is a metabolic bone disease characterized by inadequate mineralization of newly formed bone tissue, leading to softening of bones, bone pain, and increased risk of fractures, often caused by vitamin D deficiency or impaired calcium absorption.

Question 79

Rickets

Answer 79

Rickets is a childhood bone disorder characterized by defective mineralization of growing bone tissue, resulting in skeletal deformities, growth retardation, and muscle weakness, typically caused by vitamin D deficiency or dietary insufficiency.

Question 80

Bone morphogenetic proteins (BMPs)

Answer 80

Bone morphogenetic proteins are a group of growth factors that play key roles in bone development, repair, and regeneration, promoting osteogenesis and stimulating bone formation by inducing differentiation of mesenchymal stem cells into osteoblasts.