Overview of the Locomotor Module Flashcards
How do long bones develop from cartilage
Cartilage is formed first. This is then invaded by red blood cells and osteogenic cells to begin the process of bone formation. Some cartilage is left behind as the growth plates and the bone gets longer, forming the epiphysis the metaphysis and the diaphysis.
Are the cells in cartilage live or dead
Live
Are the cells in bone live or dead
Dead
What is an essential feature of bone growth
Programmed cell death (apoptosis)
What are the three zones of the growth plate from superficial to deep
Proliferative, resting and hypertrophic.
How can leg length discrepancy in children be fixed
If leg length discrepancy is caught before the growth plate has closed, you can remove some of the growth plate of the longer leg to slow its growth.
What is epiphyseodesis
The process of removal of some of the growth plate to try and ameliorate leg length discrepancy in children.
What is a Vargus deformity
Bow legs - knees point outwards
What is a Valgus deformity
Knock knees - knees point inwards.
What is arthroscopy
The use of a camera to look at bones.
Which sex is at greater risk of osteoporosis
Females
Why are females at a greater risk of developing osteoporosis
Because they start of with a lower bone mass and bone mass decreases quicker after menopause due to the loss of protective oestrogen.
What does osteoporosis increase risk of
Fracture
What are the primary causes of OP
Age, menopause, decreased renal function
What are the secondary causes of OP
Endocrine malnutrition and immobilisation.
What is rheumatoid arthritis
A chronic inflammatory condition
What happens in osteoarthritis
Articular cartilage surrounding the ends of long bones is worn away.
Why is repair of connective tissue so poor
- Poor vascular supply
- Limited nutrient supply
- Loss of cell matrix interactions
What are the four basic tissue groups
Epithelia, neural, connective and muscle.
How much of the body weight is made up by connective tissue
50%.
What are the three key components of the ECM
Fibres, ground substance and interstitial fluid.
What is an example of a fibre in the ECM
Collagen
What makes up the ground substance
Proteoglycans.
What are the three types of cartilage
Hyaline, fibro-cartilage and elastic.
What are the two types of bone
Cancellous and compact
Which three types of tissue do not strictly comply with the definition of a connective tissue
- Adipose tissue as the cells are close together within the matrix
- Lymph and blood as the fluid in which the cells are suspended was not synthesised and secreted by the cells themselves.
Which type of force is collagen good at withstanding
Tensile forces.
What type of force is collagen bad at withstanding
Compressive forces.
What type of force are proteoglycans good at withstanding
Compressive forces
What type of force are proteoglycans bad at withstanding
Tensile forces.
What are examples of resident cells in connective tissues
- Fibroblasts in most connective tissues
- Chondrocytes in cartilage
- Osteoblasts, osteoclasts and osteocytes in bone
What is the role of osteoblasts
Lay done new bone
What is the role of osteoclasts
Remove bone.
What is the role of osteocytes
To maintain bone matrix and assist bone repair.
How do resident cells link to the ECM
Integrins
What are examples of immigrant cells in connective tissues
Macrophages, lymphocytes, neutrophils, mast cells.
What is the function of fibroblasts
To synthesise and secrete components of the ECM.
Which type of collagen do fibroblasts mainly secrete
Type I collagen
What is secreted by fibroblasts into the ECM
Collagen (mainly type I), elastin, fibrillin and proteoglycans (mainly small PGs)
What is the morphology of chondrocytes
This varies. The chondrocytes at the surface of cartilage tend to be flat while those deeper tend to be round.
What is the function of chondrocytes
Synthesis, secretion and turnover of the ECM. They produce some degradative enzymes.
What is secreted by chondrocytes into the ECM
Collagen (mainly type II), and proteoglycan (aggrecan). Degradative enzymes are also secreted - cathepsins, collagenases, metalloproteinases and their inhibitors - TIMPS - issue inhibitors of metalloproteinases.
What is the main type of collagen secreted by chondrocytes
Type II collagen.
What are proteoglycans composed of
Glycosaminoglycans (GAGs)
What does the composition of the interstitial fluid depend on
The proteoglycans as these are negatively charged to attract positively charged cations and repel negatively charged anions.
What is the basketweave structure of articular cartilage
Proteoglycans are contained within a basketweave structure. The basketweave structure consists of type 2 collagen joined by type 9 collagen.
