Tissues of the Skeletal System
Bone Anatomy and Cells
Cartilage and Bone Growth
Bone Remodeling and Repair
Hormones and Calcium Regulation
100

This is the MOST COMMON type of cartilage, found covering the ends of bones and making up most of the fetal skeleton

What is Hyaline Cartilage?

100

The hollow cylindrical space within the bone shaft that contains red bone marrow in children and yellow bone marrow in adults.

What is the medullary (marrow) cavity?

100

This type of bone growth occurs within the periosteum and adds bone width throughout a person's entire lifetime.

What is appositional growth?

100

The first step of fracture repair, involving bleeding from torn blood vessels in the periosteum and subsequent blood clotting at the fracture site.

What is fracture hematoma formation?

100

This hormone, released from the thyroid gland in response to HIGH blood calcium, inhibits osteoclast activity and stimulates the kidneys to lose more calcium in urine.

What is calcitonin?

200

Unlike bone, mature cartilage lacks this crucial quality, severely limiting its ability to heal and regenerate.

What is vascularization?

200

These large, multinucleated phagocytic cells are responsible for resorption, breaking down bone matrix to release stored minerals.

What are osteoclasts?

200

The two types of ossification (bone formation) that occur during embryonic development.

What are intramembranous ossification and endochondral ossification?

200

This disease results from an imbalance between osteoclast and osteoblast activity -- excessive resorption followed by excessive but poorly formed bone deposition.

What is Osteitis Deformans (Paget Disease)?

200

Produced by the anterior pituitary, this hormone stimulates the liver to produce IGF's (somatomedins), which directly increase chondrocyte division in the epiphyseal plate

What is growth hormone (somatotropin)?

300

These two structures connect bone-to-bone and muscle-to-bone respectively, both made of densely packed collagen fibers

What are ligaments and tendons?

300

The basic structural and functional unit of compact bone, appearing as a bull's-eye target when viewed in cross-section.

What is an osteon (Haversian system)?

300

In the epiphyseal plate, this zone features chondrocytes undergoing rapid mitotic division, aligned into longitudinal columns -- directly responsible for bone lengthening.

What is the zone of proliferating cartilage?

300

During bone remodeling, these cells detect mechanical stress on bone through canaliculi connections and communicate with osteoblasts to increase bone synthesis.

What are osteocytes?

300

The three-step pathway from UV light exposure to active calcium regulation: from skin cells --> liver --> kidneys, producing this final active hormone.

What is calcitriol (activated Vitamin D)?

400

This type of cartilage is found in intervertebral discs and the menisci of the knee -- weight-bearing cartilage made of large chondrocytes interwoven with collagen fibers.

What is fibrocartilage?

400

These tiny interconnecting channels wihin bone tissue extend from each lacuna and allow nutrient, mineral, gas, and waste exchange between osteocytes and blood vessels.

What are caliculi?

400

Intramembranous ossification produces these four specific bone types -- flat skull bones, some facial bones, the mandible, and this portion of a major shoulder bone.

What is the central part of the clavicle?

400

The four sequential steps of bone fracture repair in correct order.

What are: 1) fracture hematoma, 2) fibrocartilagnious/soft callus, 3) hard/bony callus, 4) bone remodeling?

400

PTH and calcitriol act on these three effector organs to raise blood calcium levels -- one of which is the only organ influenced by calcitriol alone.

What are bone, kidneys, and small intestine? (Only caclitriol acts on the small intestine)

500

These polysaccharide molecules for the 'ground substance' in cartilage and facilitate nurient and water exchange since mature cartilage lacks blood vessels. 

What are glycosaminoglycans (GAGs)?

500

The spongy bone found between two plates of compact bone in flat skull bones, important for nervous system protection and hematopoiesis.

What is the diploe?

500

In this genetic condition, a mutation in the FGFR3 gene causes abnormal hyaline cartilage-to-bone conversion, resulting in shortened long bones but normal flat, short, and irregular bones.

What is achondroplasia (achndroplastic dwarfism)?

500
This condition, assessed by a DEXA scan, involves greatly reduced bone mass sufficient to compromise normal function, causing porous bones prone to fracture.

What is osteoporosis?

500

High amounts of these steroid hormones, released from the adrenal cortex to regulate blood glucose, can increase osteoclast activity and impair growth at the epipphyseal plate in children.

What are glucocorticoids?

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