Lab 6 — Cartilage and Bone

What are the two special connective tissues studied in Lab 6?

Cartilage and bone.

What are the two main modes of bone formation (ossification)?

Intramembranous ossification and endochondral ossification.

What are the major structures you should identify in hyaline cartilage?

Hyaline cartilage, chondrocytes, lacunae, intercellular matrix, and perichondrium.

What are chondrocytes?

Cells found in cartilage.

What is a lacuna?

A space containing a cartilage cell (chondrocyte).

What is the intercellular matrix of cartilage?

The material surrounding the chondrocytes.

What is the perichondrium?

The connective tissue layer surrounding cartilage.

What structures should you identify in elastic cartilage?

Chondrocytes, lacunae, intercellular matrix, perichondrium, and darkly stained elastic fibers.

What distinguishes elastic cartilage from hyaline cartilage histologically?

Elastic cartilage contains visible elastic fibers that stain darkly.

What is fibrocartilage also called?

Fibrous cartilage.

What structures should you identify in fibrocartilage?

Chondrocytes, lacunae, intercellular matrix, and collagenous fibers.

What type of fibers are characteristic of fibrocartilage?

Collagenous fibers.

What type of bone tissue is examined in the human bone cross-section?

Compact bone tissue.

What is an osteon?

The Haversian system, the basic structural organization seen in compact bone.

What is the central canal of an osteon also called?

The Haversian canal.

What are lamellae?

Layers of bone matrix arranged around the central canal of an osteon.

What are lacunae in compact bone?

Spaces containing osteocytes.

What are canaliculi?

Tiny channels associated with the lacunae in bone.

What structures should you identify in developing intramembranous bone?

Periosteum, trabeculae, osteoblasts, osteocytes, and osteoclasts.

What are trabeculae?

Spicules of developing cancellous bone.

Which cells actively secrete bone matrix?

Osteoblasts.

Which cells resorb bone matrix?

Osteoclasts.

Which cells are mature bone cells?

Osteocytes.

What structures are identified in developing endochondral bone?

Perichondrium, periosteum, zones of cartilage development, cartilage matrix, chondrocytes, hypertrophied chondrocytes, calcified cartilage matrix, osteoblasts, bone matrix/osteoid, osteocytes, osteoclasts, capillaries, and periosteal bone.

What are the five zones of developing endochondral bone listed in Lab 6?

Zone of resting cartilage, zone of proliferation, zone of hypertrophy, zone of calcification, and zone of ossification.

What happens in the zone of proliferation?

Chondrocytes proliferate as part of the process of endochondral bone formation.

What happens to chondrocytes in the zone of hypertrophy?

They become hypertrophied (enlarged).

What happens during the zone of calcification?

The cartilage matrix becomes calcified.

Where should you look for osteoclasts in developing endochondral bone?

Along the surfaces of the trabeculae; they are multinucleate.

What questions does Lab 6 specifically ask you to understand about endochondral bone formation?

Why chondrocytes die during endochondral bone formation, and whether calcified cartilage matrix is the same as bone matrix—and why or why not.