Bone Tissue (Part 1 of 2) Flashcards
Name the primary germ layer that bone tissue is derived from?
Bone tissue is classified as a specialised connective tissue.
Connective tissue = bone tissue = mesoderm.
Revise the functions of bone tissue and the bones of the skeleton?
Support
Protection
Movement
Mineral and growth factor storage
Blood cell formation
Fat storage
(SPM MFB)
Label the basic components and cell types in bone tissue?
Describe the basic components and cell types in bone tissue - osteoprogenitor cells, osteoblasts, osteocytes and osteoclasts?
Osteoprogenitor Cells:
- Bone stem cells that divide to produce new cells which will become osteoblasts.
Osteoblast:
- Immature bone cells
- Once they get trapped in producing a new bone matrix, some become osteocytes.
Osteocyte:
- Mature bone cells.
- Occupy small spaces within the bone matrix called lacunae.
- Maintain the bone matrix.
Osteoclast:
- Phagocytic cells.
- Break down the brown matrix (bone resorption) to aid in the development, growth, maintenance and repair of bone.
Compare and contrast the structure of compact and spongy bone - Venn diagram?
Label the key features of a compact bone?
Describe key features of a compact bone?
Osteocyte
Central canal
Canaliculi
Concentric lamellae
Osteocyte:
Located within lacunae between adjacent concentric lamellae.
Central canal:
A channel in the centre of the osteon that contains the blood vessels and nerves that supply the bone.
Canaliculi:
Small canals that connect the osteocytes within their lacunae and the central canal.
Concentric lamellae:
Rings of bone tissue that surround the central canal
Describe key features of a compact bone?
Internal Circumferential Lamellae
Interstitial Lamellae
Perforating Canals
Internal Circumferential Lamellae:
Rings of bone tissue running around the entire external and internal circumference of bones.
Interstitial Lamellae:
The incomplete rings of bone tissue in between the osteons.
Perforating Canals:
Channels that run perpendicular to the central canals and connect several central canals with each other = allowing for communication between osteons.
Label the key features of a spongy bone?
Describe the parts of a long bone?
Describe the key features of a long bone?
Proximal Epiphysis
Metaphysis
Diaphysis
Proximal Epiphysis:
Composed of an outer layer of compact bone and an inner layer of spongy bone.
Metaphysis;
In a growing long bone, the metaphysis contains the epiphyseal or growth plate = bone growth.
Diaphysis:
- Is the shaft.
- Outer layer = compact bone
- Inner = small amount of spongy bone.
- Centre = hollow space (medullary cavity), which contains yellow bone marrow.
Label the external and internal tissue coverings of bone?
Describe the external and internal tissue coverings of bone - Periosteum?
Tough sheet covering all external surfaces of bone that are not covered by cartilage.
Structure:
- Outer fibrous layer made of dense irregular connective tissue
- Inner cellular layer containing osteoprogenitor cells and osteoblasts.
Function:
- Protect the bone and provide cells for bone growth and repair.
Describe the external and internal tissue coverings of bone - Endosteum?
Thin membrane covering all internal surfaces of bone
Structure:
- Composed of a single layer of cells including osteoprogenitor cells, osteoblasts and osteoclasts.
Label the process of Intramembranous Ossification?
Label the process of Endochondral Ossification?
Compare and contrast the processes of intramembranous and endochondral ossification and provide examples of bones formed by each?
Describe the process of Interstitial Growth?
Define Interstitial Growth?
- Occurs from the epiphysial plates in each metaphysis, where cartilage is organised in different zones showing the transition from cartilage to bone.
- Growth in length
Describe the process of Appositional Growth
Define appositional growth?
- Occurs from the periosteum.
- Osteoblasts (inner cellular layer of periosteum) deposit new bone matrix = increase the width of the bone.
- Osteoclasts (endosteum) resorb old bone matrix to increase the size of the medullary cavity and remain in proportion to the width of the bone. - Growth in width
Define bone remodelling?
The balance of bone formation by osteoblasts and bone resorption by osteoclasts.
Describe the process of bone remodelling?
Controlled by hormones and mechanical stress placed on bone.
