Anatomy And Physiology: Skeletal System

Cartilage

Contributes to the skeletal system, providing rigid support framework, allowing movement, protection for soft internal organs, storing minerals, energy, and production of blood cells.

Hyaline Cartilage

Type of cartilage found at the ends of bones where they form joints, helps bones glide past one another, and loss leads to osteoarthritis.

Fibrocartilage

Type of cartilage found between vertebrae, within the knee, and the pubic symphysis.

Long Bone

Cylinder-like shape, longer than it is wide, providing leverage and examples include femur, tibia, fibula, metatarsals, humerus, ulna, radius, metacarpals, and phalanges.

Short Bone

Cube-like shape, approximately equal in length, width, and thickness, providing stability, support, and allowing for some motion. Examples include carpals and tarsals.

Flat Bone

Thin and curved bones serving as points of attachment for muscles and protectors of internal organs. Examples include sternum, ribs, scapulae, and cranial bones.

Irregular Bones

Bones with a complex shape that protect internal organs. Examples include vertebrae and facial bones.

Sesamoid Bones

Small and round bones embedded in tendons, protecting tendons from compressive forces.

Epiphyseal Line

Site of the previous epiphyseal plate, found in long bones.

Periosteum

Dense irregular connective tissue lining the surface of bones, containing blood vessels, nerves, and lymphatic vessels.

Endosteum

Dense irregular connective tissue lining the medullary cavity, containing cells that allow bone growth.

Articular Cartilage

Found at the ends of long bones where joints form, made of hyaline cartilage, reducing friction, and acting as a shock absorber.

Bone Markings

Surface features of bones including articulating surfaces, depressions, projections, holes, and spaces.

Chondroblasts

Cells of cartilage that secrete matrix.

Chondrocytes

Cells completely surrounded by matrix, found in lacunae.

Compact Bone

Solid connective tissue consisting of osteons, providing support, protection, and strength to bones.

Spongy Bone

Less dense bone tissue with spaces housing red bone marrow, providing strength and support.

Osteogenic Cells

Stem cells that replicate and develop into osteoblasts, communicating via canaliculi.

Osteoblasts

Cells that form new bone matrix.

Osteocytes

Mature osteoblasts completely surrounded by matrix, located in lacunae.

Osteoclasts

Cells that breakdown bone and aid in bone remodeling

Primary Ossification Center

Location where mineralization increases and bone formation begins

Intramembranous Ossification

Process where connective tissue membrane forms flat bones of the cranium and face

Endochondral Ossification

Process using hyaline cartilage to form most long bones, with minerals deposited on collagen fibers

Appositional Cartilage Growth

Cartilage growth in width due to chondroblasts secreting matrix

Interstitial Cartilage Growth

Cartilage growth in length through mitotic replication of chondrocytes

Epiphyseal Plate

Plate that allows bones to grow in length by replacing cartilage with bone

Reserve Zone

Anchors epiphyseal plate to epiphysis and occurs through appositional growth

Proliferative Zone

Zone where osteoblasts form new bone matrix and chondrocytes undergo mitosis

Zone of Mature Cartilage

Zone with older, mature chondrocytes surrounded by bone matrix

Zone of Calcified Matrix

Zone with dead chondrocytes surrounded by bone matrix, anchoring epiphyseal plate to diaphysis

Bone Remodeling

Daily changes in bone through breakdown and formation, aiding in homeostasis

Blood Calcium Regulation

Process where hormones like calcitonin and parathyroid hormone regulate calcium levels in bones

Bone Repair

Steps involving hematoma, cartilage callus, bone replacement, and compact bone formation for healing

Growth Hormone (GH)

Hormone promoting bone growth

Oblique Fracture

Fracture occurring at an angle not 90 degrees, requiring alignment for healing

Transverse Fracture

Fracture occurring straight across the long axis of the bone

Closed Fracture

Fracture where the skin remains intact

Open Fracture

Fracture where at least one end of the broken bone tears through the skin

Greenstick Fracture

Partial fracture where only one side of the bone is broken

Impacted Fracture

Fracture where one fragment is driven into the other, often due to compression

Comminuted Fracture

Fracture with several breaks resulting in many small pieces between two large segments

Spiral Fracture

Fracture where bone segments are pulled apart due to a twisting motion

Calcium Homeostasis

Process involving calcitonin and parathyroid hormones to regulate calcium levels in bones

Vitamin D Synthesis

Process where the human body produces active forms like calcitriol and calcidiol for calcium absorption

Dietary Calcium

Sources of dietary calcium including cheese, milk, nuts, leafy greens, and fish

Exercise and Bone Tissue

Strengthening of bones through exercise and physical stress, leading to thicker, denser bone

Importance of Vitamin D

Synthesis by the body, supplementation in foods, and role in bone health

Osteoporosis

Condition characterized by decreased bone mass with age, where osteoclast activity exceeds osteoblast activity