Chapter 6 Anatomy

Collagen and calcium-binding proteins.

In the heads of the femur and humerus, and in the diploë of flat bones.

They respond to increased force on bone or weightlessness.

It can convert to red marrow if a person becomes anemic.

Open (compound) fractures penetrate the skin, while closed (simple) fractures do not.

Until early adulthood.

Projections, surfaces, and depressions/openings.

They are bone-forming cells that secrete unmineralized bone matrix called osteoid.

They are giant, multinucleate cells that function in bone resorption (breakdown of bone).

In depressions called resorption bays.

Calcification of cartilage.

Females around 18 years of age and males around 21 years of age.

Through appositional growth, which can occur throughout life.

Osteocytes.

In bone.

The periosteum covers the outside, and the endosteum covers the inside portion.

Hard inorganic components such as mineral salts.

They are mitotically active stem cells that can differentiate into osteoblasts or bone-lining cells.

Hematoma formation.

Torn blood vessels hemorrhage, forming a mass of clotted blood called a hematoma.

Reduction, immobilization, and healing time depending on severity, bone, and age.

They divide and secrete new matrix, expanding cartilage from within.

Fibrocartilaginous callus.

Because they contain different types of tissues, including osseous tissue, nervous tissue, cartilage, fibrous connective tissue, muscle cells, and epithelial cells in blood vessels.

New trabeculae appear in the fibrocartilaginous callus, converting it to a bony callus of spongy bone.

Gross, microscopic, and chemical.

Bone remodeling.

A dense outer layer on every bone that appears smooth and solid.

Approximately every 10 years.

Hairlike canals that connect lacunae to each other and to the central canal.

It resembles the original structure and responds to the same mechanical stressors.

Osteoclasts.

Sites of muscle, ligament, and tendon attachment, areas involved in joint formation, or conduits for blood vessels and nerves.

The process of bone tissue formation.

Flat cells on bone surfaces believed to help maintain the bone matrix.

Sesamoid bones form within tendons; an example is the patella.

Flat bones are thin, flat, and slightly curved; examples include the sternum, scapulae, ribs, and most skull bones.

Irregular bones have complicated shapes; examples include vertebrae and hip bones.

Hematopoiesis occurs in red marrow cavities of certain bones.

Canals lined with endosteum that occur at right angles to the central canal, connecting blood vessels and nerves.

The center of the shaft where ossification begins.

Skull, vertebral column, and rib cage.

Growth hormone.

Bones that are longer than they are wide, such as limb bones.

Canaliculi form, allowing communication between osteocytes.

Bone is half as strong as steel in resisting compression.

A band of unmineralized bone matrix that marks the area of new matrix.

Osteoprogenitor cells, osteoblasts, osteocytes, bone lining cells, osteoclasts, and osteoid.

Vitamin D deficiency or insufficient dietary calcium.

Osteoid is secreted by osteoblasts and consists of ground substance and collagen fibers.

Bone-sparing drugs.

Sacrificial bonds in or between collagen molecules.

It appears poorly organized but is actually organized along lines of stress.

Because compression and tension cancel each other out in the center of the bone.

It slows bone loss.

Breaks in the bone.

Highly resilient, molded cartilage tissue that consists primarily of water.

Mature bone cells in lacunae that no longer divide, maintaining bone matrix and acting as stress sensors.

They communicate information to osteoblasts and osteoclasts.

90%.

Osteoprogenitor cells, osteoblasts, osteocytes, bone-lining cells, and osteoclasts.

Bone forms by replacing hyaline cartilage.

Approximately every 3-4 years.

It runs through the core of the osteon and contains blood vessels and nerve fibers.

Osteoblasts secrete bone matrix on the external surface, while osteoclasts remove bone on the endosteal surface.

Bone deposit and bone resorption.

Only in epiphyseal plates and articular cartilages.

They modulate the activity of growth hormone, ensuring proper proportions.

Imbalances between bone deposit and bone resorption.

Frontal, parietal, occipital, temporal bones, and clavicle.

It stimulates osteoclasts to resorb bone, releasing calcium into the blood.

Hyaline cartilage.

Adequate Calcium and Vitamin D intake.

Results in bowed legs and other bone deformities due to enlarged and abnormally long bone ends.

About one-third organic and two-thirds inorganic matter.

Right- or left-handedness results in thicker and stronger bone in the corresponding upper limb.

Bones, cartilages, and ligaments.

Electrical currents created by fluid movement through canaliculi.

They attach muscle to bone.

Calcitonin and bisphosphonates.

A glistening white, double-layered membrane that covers external surfaces except joints.

Bones are well vascularized with nutrient arteries and veins serving the diaphysis.

In the second month of development.

Endochondral ossification and intramembranous ossification.

Chondrocyte deterioration leaves long spicules of calcified cartilage, which are eroded by osteoclasts and covered with new bone by osteoblasts.

The structural unit of compact bone, consisting of an elongated cylinder that runs parallel to the long axis of the bone.

About 5–10%.

Most bones of the skeleton, except clavicles.

Into axial skeleton and appendicular skeleton.

Excess material is removed, and compact bone is laid down to reconstruct shaft walls.

1. Bone collar forms, 2. Central cartilage calcifies, 3. Periosteal bud invades cavities, 4. Diaphysis elongates, 5. Epiphyses ossify.

Vitamin D.

Lysosomal enzymes and protons (H+).

Weight-bearing exercise.

Calcitonin.

Increased risk of breast cancer, stroke, and heart disease.

Fosamax and Actonel.

Deposits of calcium salts in blood vessels or kidneys and formation of stones.

A PTH derivative that increases density by 10% in 1 year.

Excessive and haphazard bone deposit and resorption.

Soft organic components such as bone cells and osteoid.

Its thick collagen fibers and great tensile strength.

Surrounding cartilage matrix calcifies; chondrocytes die and deteriorate.

Fibroblasts secrete collagen fibers to span the break and connect broken ends.

It thins and is replaced by bone, leading to epiphyseal plate closure.

Support, protection, anchorage, mineral and growth factor storage, blood cell formation, triglyceride storage, and hormone production.

Several rings of bone matrix called lamellae, which contain collagen fibers.

It is essential for maintaining extracellular homeostatic fluid levels, nerve firing, and muscle contraction.

It is made up of a honeycomb of small, needle-like or flat pieces of bone called trabeculae.

Long bones, short bones, flat bones, and irregular bones.

Via cell projections with gap junctions.

A process that begins within fibrous connective tissue membranes formed by mesenchymal cells.

Parathyroid hormone (PTH).

Yellow marrow.

Excesses or deficits of any hormones.

Bones tend to bend.

Through interstitial (longitudinal) growth of the epiphyseal plate.

Help long bones resist twisting by extending around the entire surface of the diaphysis.

Compression occurs on one side, while stretching occurs on the other side.

65%.

Bones stop growing, although some facial bones may continue to grow slowly.

They confer strength to bone, similar to cables on a suspension bridge.

They can cause remodeling, resulting in increased bone strength.

Bone that has a very high ratio of spongy to compact bone and reduced mineralization.

It serves as the forerunner of most bones and covers many joint surfaces of mature bone.

Nondisplaced (normal position) and displaced (out of alignment).

The fibrous layer (outer) and the osteogenic layer (inner).

They service the epiphysis of the bone.

It has a shaft (diaphysis), bone ends (epiphyses), and membranes.

They promote adolescent growth spurts and induce epiphyseal plate closure.

Osteomalacia and rickets, osteoporosis, and Paget’s disease.

Hypercalcemia, which causes nonresponsiveness.

Hormonal controls and response to mechanical stress.

Aged, postmenopausal women.

Over-modified collagen molecules and thinner collagen fibers.

A remnant of childhood where bone growth occurs.

In articular surfaces, costal areas, respiratory structures, and the nasal tip.

Cartilage-forming cells in the perichondrium secrete matrix against the external face of existing cartilage.

Cube-shaped bones found in the wrist and ankle.

Lamellae that are not part of an osteon, filling gaps between forming osteons.

1. Ossification centers form; 2. Osteoid is secreted and calcified; 3. Woven bone forms around blood vessels; 4. Lamellar bone replaces woven bone.

The abrupt transition zone between the osteoid seam and older mineralized bone.

Bones are poorly mineralized, resulting in soft, weak bones and pain upon bearing weight.

Hypocalcemia, which causes hyperexcitability.

It removes phosphate ions from osteoid proteins, increasing local concentrations of phosphate ions.

The process by which bones increase in thickness.

Increased calcium ion concentration.

Bone resorption exceeds deposit, leading to a decline in bone mass.

Where bending stresses are greatest.

It states that bones grow or remodel in response to the demands placed on them.

Spongy bone of the spine and neck of the femur.

An area of cartilage on the epiphyseal side that is relatively inactive.

Rickets is a vitamin D deficiency causing hypomineralization, preventable through supplementation.

1. Proliferation (growth) zone; 2. Hypertrophic zone; 3. Calcification zone; 4. Ossification (osteogenic) zone.

Estrogen helps maintain bone density, and its drop at menopause increases the risk of osteoporosis.

Cartilage on the diaphysis side rapidly divides, pushing the epiphysis away from the diaphysis.

Insufficient exercise, poor diet in calcium and protein, smoking, genetics, and hormone-related conditions like hyperthyroidism.

Where they are most likely to buckle.

Bone is made up of both organic components (like bone cells and osteoid) and inorganic components.

Older chondrocytes enlarge and erode, forming interconnecting spaces.

Trabeculae.

In the spine, pelvis, femur, and skull.

They become featureless due to lack of stress.

Loss of tissue mass due to disease or lack of use.

Before age 40.

They hold bones together at the joints.

A virus.

Hormonal controls in response to changing blood calcium levels.

It initially consists of just cartilage, which is later replaced by bone.

Articular cartilage, which is a layer of hyaline cartilage.

It allows joints to move more freely and relatively friction-free.

Complete (broken all the way through) and incomplete (not broken all the way through).

A delicate connective tissue membrane covering the internal bone surface.

A layer of dense connective tissue surrounding cartilage that helps resist outward expansion.

Cells encased in small cavities (lacunae) within the jelly-like extracellular matrix of cartilage.

Appositional growth and interstitial growth.

Periosteum and endosteum.

Endosteum, which contains reticular connective tissue.

Hyaline cartilage, elastic cartilage, and fibrocartilage.

They supply bone marrow and spongy bone, branching outward to supply compact bone.

They secure the periosteum to the underlying bone.

Elastic cartilage contains elastic fibers, while hyaline cartilage contains only collagen fibers.

Nerves, which also pass through nutrient foramen.