Human Bone Development and Structure

PTH stimulates osteoclasts to increase bone breakdown, raising blood calcium levels, while CT inhibits osteoclasts to promote bone formation, decreasing blood calcium levels.

Hypocalcemia is caused by low blood levels of calcium, potentially leading to muscle spasms, and neurological symptoms.

PTH increases blood calcium levels by stimulating osteoclasts, which break down bone and release calcium into the bloodstream.

<p>Calcitonin lowers blood calcium levels by inhibiting osteoclast activity, leading to increased bone formation and calcium storage.</p> Signup and view all the answers

<p>Calcium absorption in the intestines requires vitamin D, as it enhances the efficiency of calcium uptake.</p> Signup and view all the answers

<p>Lamellae form concentric rings around the central canal, providing structural support and facilitating the distribution of nutrients and waste.</p> Signup and view all the answers

<p>Canaliculi allow for communication and nutrient exchange between osteocytes located in lacunae.</p> Signup and view all the answers

<p>Compact bone is dense and structured with tightly packed osteons, while cancellous bone is more porous with trabeculae and spaces filled with bone marrow.</p> Signup and view all the answers

<p>The periosteum provides a protective outer layer, promotes bone growth and repair, and serves as an attachment point for muscles and tendons.</p> Signup and view all the answers

<p>Osteocytes maintain bone tissue by regulating mineral content and signaling for bone remodeling.</p> Signup and view all the answers

<p>They are crucial for the formation of different bones in the skull.</p> Signup and view all the answers

<p>The perichondrium becomes periosteum, and a bone collar forms as chondrocytes hypertrophy and cartilage calcifies.</p> Signup and view all the answers

<p>Osteoblasts invade the calcified cartilage and lay down bone matrix, creating trabeculae.</p> Signup and view all the answers

<p>It allows for the lengthening of bones as chondrocytes divide and calcified cartilage is replaced by bone.</p> Signup and view all the answers

<p>Secondary ossification centers form in the epiphyses, whereas primary centers originate in the diaphysis.</p> Signup and view all the answers

<p>The thickness remains unchanged even as the length of the bone increases.</p> Signup and view all the answers

<p>Chondrocytes divide and enlarge, leading to the replacement of calcified cartilage with bone.</p> Signup and view all the answers

<p>The main types include flat bones such as the parietal, frontal, and occipital bones.</p> Signup and view all the answers

<p>Interstitial cartilage growth contributes to bone lengthening through the mitotic replication of chondrocytes that allows cartilage to grow in length.</p> Signup and view all the answers

<p>Chondroblasts, which differentiate from cells in the perichondrium, secrete matrix that allows cartilage to increase in width.</p> Signup and view all the answers

<p>During interstitial cartilage growth, chondrocytes undergo mitosis, initially sharing the same lacuna and later moving apart as they secrete matrix.</p> Signup and view all the answers

<p>The perichondrium contributes to appositional cartilage growth by differentiating its cells into chondroblasts, which then secrete matrix.</p> Signup and view all the answers

<p>Interstitial growth increases cartilage length through chondrocyte mitosis, while appositional growth increases width through matrix secretion by chondroblasts.</p> Signup and view all the answers

<p>Appositional growth is the process where osteoblasts in the periosteum lay down new bone matrix on the surface, allowing bones to grow in diameter.</p> Signup and view all the answers

<p>Osteoclasts break down older bone tissue that lines the medullary cavity, facilitating the reshaping and remodeling of bones.</p> Signup and view all the answers

<p>Primary ossification centers are areas where bone tissue begins to form, typically located in the diaphyses of long bones in the lower limb of the fetus.</p> Signup and view all the answers

<p>Intramembranous ossification forms bone directly from mesenchymal tissue, while endochondral ossification involves the replacement of cartilage with bone.</p> Signup and view all the answers

<p>The parietal, temporal, and mandible bones are primarily formed through intramembranous ossification.</p> Signup and view all the answers

<p>The medullary cavity in young bone contains red marrow, while in adult bone it contains yellow marrow.</p> Signup and view all the answers

<p>Epiphyseal lines indicate that bone growth has ceased, whereas epiphyseal plates are areas of active growth in young bones.</p> Signup and view all the answers

<p>Haversian systems consist of osteons, central canals, and connecting vessels, primarily functioning to provide structural integrity and facilitate nutrient transport.</p> Signup and view all the answers

<p>The periosteum serves as a protective outer layer and a site for muscle attachment in both young and adult bones.</p> Signup and view all the answers

<p>Both young and adult bones have cancellous and compact bone; however, the distribution and density may differ, influencing the overall strength and weight of the skeleton.</p> Signup and view all the answers

<p>Osteogenic cells are stem cells that replicate and develop into osteoblasts, contributing to bone formation.</p> Signup and view all the answers

<p>Osteocytes communicate via canaliculi, slender channels that allow for nutrient and waste exchange.</p> Signup and view all the answers

<p>Spongy bone has a porous structure that provides strength while housing red bone marrow, unlike the dense structure of compact bone that provides support and protection.</p> Signup and view all the answers

<p>Osteoclasts are responsible for breaking down bone tissue, facilitating the remodeling process.</p> Signup and view all the answers

<p>Lacunae are small cavities in bone tissue that house mature osteocytes, allowing for their maintenance and survival.</p> Signup and view all the answers

<p>Concentric lamellae provide structural support and strength to the osteon by organizing the matrix around the central canal, allowing for efficient nutrient transport.</p> Signup and view all the answers

<p>Trabeculae form a lattice-like network that aligns along stress lines, providing strength while maintaining a lightweight structure.</p> Signup and view all the answers

<p>Canaliculi allow for the exchange of nutrients and waste between osteocytes and the central canal, supporting cellular health.</p> Signup and view all the answers

<p>Perforating canals provide a pathway for blood vessels to connect the central canal to the periosteum, facilitating nutrient delivery to the bone.</p> Signup and view all the answers

<p>Red bone marrow is crucial for hematopoiesis, the production of blood cells, and its location in spongy bone supports this process.</p> Signup and view all the answers

<p>Hyaline cartilage aids in joint movement and reduces friction between bones; loss of this cartilage leads to osteoarthritis.</p> Signup and view all the answers

<p>Bones store calcium and other minerals, which are essential for various bodily functions, including muscle contraction and nerve signal transmission.</p> Signup and view all the answers

<p>Cartilage provides smooth surfaces for joint movement and shock absorption, while bone offers structural support and protection for internal organs.</p> Signup and view all the answers

<p>Bone and cartilage work together, with bone providing a hard outer structure for protection and cartilage offering cushioning at the joints.</p> Signup and view all the answers

<p>Adipose tissue stored in bone serves as an energy reserve and helps in the regulation of body temperature.</p> Signup and view all the answers

<p>Chondroblasts secrete matrix, allowing cartilage to increase in width.</p> Signup and view all the answers

<p>Bones grow in length as the epiphyseal plate grows, increasing the distance between the epiphysis and diaphysis while cartilage on the diaphysis side is replaced with bone.</p> Signup and view all the answers

<p>The reserve zone anchors the epiphyseal plate to the epiphysis.</p> Signup and view all the answers

<p>The four zones are the reserve zone, proliferative zone, zone of mature cartilage, and zone of calcified matrix, each contributing to the regulation of bone growth.</p> Signup and view all the answers

<p>As cartilage on the diaphysis side of the epiphyseal plate is replaced with bone, this process results in the overall lengthening of the bone.</p> Signup and view all the answers