Bone and Connective Tissue Flashcards
What is bone tissue?
A supporting connective tissue.
What makes up bone tissue?
Collagen and calcium phosphate crystals
What makes up 2/3 the weight of the bone?
Calcium phosphate crystals
What makes up 1/3 the weight of the bone?
Collagen fibres
What adds flexibility to the bone?
Collagen fibres
What adds strength and weight-baring capabilities?
Calcium phosphate crystals called hydroxyapatite
What types of cells comprise osseous tissue?
Osteocytes
Osteoblasts
Osteoclasts
Osteoprogenitors
What are Osteocytes?
Mature bone cells
Found in small packets called lacunae
Sandwiched between layers of calcium matrix known as lamella.
What are Osteoblasts?
Responsible for the production of new bone, a process called osteogenesis.
What is osteogenesis?
The production of new bone.
What are osteoclasts?
Giant cells with 50 or more nuclei.
Dissolves the bony matrix and releases the stored minerals of calcium phosphate.
What is osteolysis?
The process of osteoclasts dissolving the bony matrix.
What is the relationship between Osteoblasts and Osteoclasts?
Osteoblasts produce new bone. Osteoclasts dissolve bone tissue.
What are osteoprogenitor cells?
These cells produce daughter cells that can differentiate into osteoblasts. Play a role in fracture repair.
What are the two types of bone tissue?
Cortical or compact
Cancellous or spongy
Describe cortical bone.
Forms the hard outer layer and is found in the shafts of long bones.
What is the hard outer layer of bone that consists of a number of cylindrical structures called?
Osteons or haversian systems
What makes up a haversion system?
Central aversion canal - contains blood, lymphatic vessels and nerves
Lamellae - rings of bone around the haversian system
Lacunae - spaces between the lamellae, which contain osteocytes (mature bone cells)
Canaliculi - channels carrying nutrient fluid which connect the lacunae and communicate with the aversion canal
Interstitial lamellae - fill the spaces between adjacent aversion systems
Volkmann’s canals - join the various haversion canals
Describe cancellous bone.
Found in the part of the bones where lightness, strength and area are needed.
Present at the ends of long bones
These regions are the heads or epiphyses
What are the ends of long bones called?
Epiphyses
What is the name of the membrane that surrounds the outer layer of the bone?
The periosteum
What is the function of the periosteum?
To isolate the bone from the surrounding tissues
To provide a route for circulatory and nervous supply
To actively participate in bone growth and repair
Near joints the fibrous layer of the periosteum blends with the connective tissues and bind the bones together.
At a joint the periosteum is continuous with the joint capsule.
When does the bony skeleton begin to form in the fetus?
6 weeks after fertilization. Before this time the skeletal elements are cartilaginous.
When does bone growth stop?
Early 20s.
What is the process of replacing other tissues with bone?
Ossification
What term describes the deposition of calcium salts within a tissue?
Calcification