Bone
Basics
Basics
Femur is an example of what bone shape?
Long bone
What is the basic structural unit of compact bone?
Osteon
Which cell builds new bone?
Osteoblast
Which condition refers to abnormally low blood calcium?
Hypocalcemia
A student injures a structure that connects muscle to bone. What structure was injured?
Tendon
These bones allow tendons to move more efficiently
Sesamoid bones
What tiny channels allow osteocytes to communicate?
Canaliculi
An osteoblast becomes trapped within the bone matrix it produced. What does it become?
Osteocyte
A patient has too much calcium in their blood. Which condition does this describe, and what does “hyper-” indicate?
Hypercalcemia; “hyper-” means above/high
A student straightens their knee after having it bent while sitting in a chair. What movement is occurring?
Extension
What structure covers the outer surface of a long bone and contains blood vessels and nerves?
Periosteum
An osteon contains concentric circles called lamellae (layers of bone matrix). Why does this arrangement make compact bone strong?
The layered arrangement helps distribute forces, making it stronger
A structure is damaged at the knee. It connects bone to bone and helps prevent excessive movement of the joint. What is it?
Ligament
A patient has low blood calcium levels. Would you expect osteoclast activity to increase or decrease?
Increase
A student moves their arm away from the midline of their body. What movement is occurring?
Abduction
A student sees trabeculae in a bone sample and concludes that the bone is poorly structured because it has empty spaces. Why is this incorrect?
The spaces between trabeculae help keep spongy bone lightweight while the trabeculae provide support
What are the branching structures found in spongy bone?
Trabeculae
A joint needs a smooth, low-friction surface where two bones meet and also needs to withstand compression. Which type of cartilage is best suited for this role?
Hyaline cartilage
A patient has low blood calcium. Which bone cell would become more active, and what would that cell do?
Osteoclasts; break down bone and release calcium into the blood
Generally, males tend to reach a greater average adult height than females. Which explanation best connects this to the skeletal system?
Males generally enter puberty later, so epiphyseal plates remain open longer, allowing more time for long bones to grow before plates close
A student says the epiphysis is the long middle portion of a long bone. What is wrong with this statement?
The epiphysis is the expanded end; the diaphysis is the shaft/middle portion
A student says spongy bone is weak because it doesn't contain osteons. Explain why this is incorrect.
Trabeculae provide structural support while keeping bone lightweight
A bone needs to increase its calcium release into the blood. Which bone cell would become more active, and what would it do?
Osteoclast → breaks down bone matrix and releases calcium
A student says, “Osteoblasts increase blood calcium because they build bone.” Is this correct? Explain.
No. Osteoblasts build bone and help store calcium in bone; osteoclasts release calcium
A fracture starting to heal. New tissue forms between the broken ends of bone. Which stage of fracture repair is occurring?
Fibrocartilaginous callus (Soft callus)