chap 6

What are the three types of cartilage?

Hyaline, Elastic, Fibrocartilage

Where is hyaline cartilage found?

Joints, nose, ribs, larynx, and trachea

What makes elastic cartilage different?

It contains elastic fibers, allowing it to bend (found in ear & epiglottis).

What is the strongest type of cartilage?

Fibrocartilage – found in intervertebral discs & knee menisci.

What are the five main functions of bones?

Support, movement, protection, mineral storage, blood cell formation, energy metabolism.

How does bone help with energy metabolism?

Osteoblasts secrete osteocalcin, which regulates energy and fat storage.

What are the two main components of bone?

Organic (35%) – Cells, collagen fibers → flexibility; Inorganic (65%) – Mineral salts (calcium phosphate) → hardness.

What are the four types of bone cells?

Osteoprogenitor cells, osteoblasts, osteocytes, osteoclasts.

What is the function of osteoblasts?

Build bone by producing the bone matrix (osteoid).

What do osteoclasts do?

Break down bone to release calcium.

What are the four types of bones?

Long, short, flat, irregular.

Give an example of each type of bone.

Long – Femur; Short – Carpals; Flat – Sternum; Irregular – Vertebrae.

What are the two types of bone tissue?

Compact bone (dense outer layer) & spongy bone (internal network).

What is the hollow space inside long bones called?

Medullary cavity – filled with yellow marrow (fat storage).

What is ossification (osteogenesis)?

The process of bone tissue formation.

What type of ossification forms skull bones?

Intramembranous ossification.

What is the main cartilage type involved in endochondral ossification?

Hyaline cartilage.

What is the function of the epiphyseal (growth) plate?

Helps bones grow in length.

When does bone growth stop?

When the epiphysis and diaphysis fuse (end of adolescence).

What type of growth allows bones to become wider?

Appositional growth.

Which hormone stimulates the epiphyseal plates?

Growth hormone.

What does thyroid hormone do for bones?

Ensures proper proportions.

What do sex hormones (estrogen & testosterone) do?

Promote growth during puberty and later close growth plates.

What happens to bones over time?

They are constantly being broken down and rebuilt (remodeled).

Which cells are responsible for bone deposition?

Osteoblasts.

Which cells are responsible for bone resorption?

Osteoclasts.

How often is spongy bone replaced?

Every 3–4 years.

How often is compact bone replaced?

Every 10 years.

What type of fracture does NOT break the skin?

Simple (closed) fracture.

What type of fracture pierces the skin?

Compound (open) fracture.

What are the four stages of bone healing?

Hematoma Formation – Blood clot forms; Fibrocartilage Callus – Soft repair tissue forms; Bony Callus – Hard bone replaces soft tissue; Bone Remodeling – Bone returns to normal shape.

What is osteoporosis?

A condition where bones become weak due to low bone mass.

What causes osteoporosis?

Bone resorption (breakdown) outpaces bone deposition.

Who is most at risk for osteoporosis?

Women after menopause.

What is osteomalacia?

Soft bones due to poor mineralization (in adults).

What is rickets?

Soft bones due to vitamin D deficiency (in children).

What is osteosarcoma?

A type of bone cancer.

What happens to bone formation in young children?

Bone formation is faster than bone breakdown.

What happens to bones in old age?

Bone resorption (breakdown) becomes faster than bone formation → bone loss.