Lecture 5 - Bone Growth Flashcards
What are the basic steps from cartilage to mineralized tissue?
- Start of calcification (turning into a more mineral aspect similar to what we get in normal bone)
- Blood vessels and osteoblasts form bone on the surface of the cartilage
- Blood vessels taking osteoblasts to the Centre to form a calcified matrix
- Primary ossification centre developed (diaphysis or shaft of bone)
The diaphysis are primary ossification Centre’s and the epiphyses remain cartilage when the primary ossification Centre has been developed. What is the secondary ossification Centre?
The epiphyses go through the same ossification process as primary centers and is separated from diaphysis by an epiphyses plate.
What is another word for growth plate?
Epiphyseal plate
What is the diaphysis?
The diaphysis is the internal structure of a human long (shaft) bone, with a magnified cross section of the interior. It is made up of cortical bone and usually contains bone marrow and adipose tissue (fat)
What is cortical bone?
Cortical bone is the dense outer surface of the bone that forms a protective layer around the internal cavity - this is also known as contact bone.
What is the process of transforming cartilage to bone called?
Endochondral ossification
Growth in length is?
Through growth plate
Growth in width is?
- Appositional growth (increase in the diameter of bones by the addition of bony tissue at the surface of our bones)
- Osteoblasts activity produces circumferential lamellae
- Osteocytes mould the bone shape and form the medullary cavity
What is a joint?
A joint is where two bones meet (articulation) A joint involves bone shapes and soft tissues and allows free movement/ control of movement.
What are the two types of cartilage associated with joints?
- Hyaline (articular)
2. Fibrocartilage
What is the general cartilage composition?
- Collagen fibers in a ground substance, chondrocytes in lacuna
- Blood vessels don’t penetrate cartilage
- Nutrients diffused through matrix by joint loading
What are the properties of Hyaline (articular) cartilage?
- Collagen fibers are barely visible
- High water content in matrix
- Function = resist compression
- Smooth, frictionless surface
What is a chondrocyte?
A chondrocyte is a cartilage cell that occur at scattered sites through the cartilage and receive nutrition by diffusion through the gel
What are the functions of hyaline cartilage in joints?
- Mounds to surface our bones where they articulate
- Frictionless, smooth movement
- Degrades with age
What are the properties of fibrocartilage?
- Collagen fibers form bundles throughout matrix
- Orientation of fibers aligns with stresses
- Function = resist compression and tension
What are the functions of fibrocartilage in joints?
- Generally at articulations that experience both compression and tension
- Deepening of articular surfaces
- Acts as a buffer/shock absorber (distributed force over a wider area)
What do ligaments do?
- Connect muscle to bone
- Facilitates and controls movement
- Will restrict movement medi
What do tendons do?
- Connect muscle to bone
- Facilitate and control movement
- Contraction of muscles transmitted to bone
What is bony congruence?
Bony congruence is the sum of the bone surfaces that form an articulation. Some joints need less support than other joints. Less congruence = more soft tissue to make joint stable
What is tissue?
Cells grouped together in a highly organized manner according to specific structure and function
What is structure?
Something formed of a tissue (e.g meniscus)
What are the three types of joints based on the amount of movement possible and the tissue present?
- Fibrous
- Cartilaginous
- Synovial
What are fibrous joints?
The fibrous joint has dense fibrous connective tissue which forms ligaments. The structure of fibrous joints are ligaments and their function is to limit movement and provide stability. E.g cranial sutures
What are cartilaginous joints?
Cartilaginous joints are more mobile than fibrous joints and have fibrocartilage as their tissue. They allow some movement, pressure and tension. They have various structures with special functions. E.g pubic symphysis (joint) two halves of pelvis
