Bones and Joints Flashcards
What are the different types of bones?
Long e.g limbs
Short e.g carpals in wrist
Flat e.g skull
Sesamoid e.g patella
Irregular e.g vertebrae
What are the functions of bone?
Support and weight bearing
Protection
Blood formation
Mineral storage
Name the membrane which covers bone and it’s function
Periosteum, lays down more bone
Name the membrane which lines the inside of bone
Endosteum
What is an osteon?
The circular structures in which compact bone is organised
State the difference between Haversian systems and Volkmann’s canals
Haversian systems run vertically through the centre off osteons
Volkmann’s canals run horizontally between Haversian canals
Name the 3 types of cells found in bone
Osteoclasts
Osetoblasts
Osteocytes
Describe the function of osteoclasts and their origin
Osteoclasts reabsorb bone matrix
Large multinucleate cells derived from haemopoietic stem cells
Describe the function of osteoblasts and their origin
Osteoblasts produce unmineralised bone matrix (osteoid) and initiate calcification
Immature bone cells created from osteoprogenitor cells in the periosteum and endosteum
Describe the function of osteocytes and their origin
The function of osteocytes is not well understood, but may maintain bone matrix and sense mechanical forces
Mature bone cells found inside lacunae (cavity/ depression)
Describe the composition of the bone extracellular matrix
45% Hydroxyapatite crystals
35% Type I Collagen fibres
20% Water
Name 3 examples of bone remodelling disorders
Osetoporosis
Paget’s disease
Osteopetrosis
Why are limb bones long?
Limb bones are used for movement
Why do trunk bones vary between being long, flat and irregular?
Trunk bones are used for protection
What is cartilage?
Cartilage is a semi-rigid and flexible connective tissue
What is the function of cartilage?
Cartilage supports tissues and organs and provides a scaffold for bone development
Name the 2 kinds of cells found in cartilage
Chrondroblasts
Chondrocytes
Describe the function of chondroblasts and their origin
Chondroblasts secrete extracellular matrix and fibres
Immature cells derived from mesenchyme cells
Describe the function of chondrocytes and their origin
Chondroblasts secrete extracellular matrix and fibres
Mature cells derived from chordroblasts (once they have become embedded in cartilage matrix)
Where is cartilage found?
The end of long bones at the joints
What are the three types of cartilage?
Hyaline
Elastic
Fibrocartilage
Where is elastic cartilage found?
External ear
Epiglottis
Where is hyaline cartilage found?
Ribs
Nose
Trachea
Where is fibrocartilage found?
Intervertebrae disks
What structures cannot be found in cartilage?
Blood vessels and nerves
Describe briefly the characteristics of each type of cartilage
Hyaline - weakest and glassy appearance
Elastic - flexible and resistant
Fibrocartilage - strongest type of cartilage
What are the two different parts of the skeleton called?
Axial
Appendicular
Where in a long bone can compact bone be found?
Compact bone is found on the surface
Where in a long bone can spongy bone be found?
Spongy bone is found inside the bone
What type of bone is found inside the marrow cavity?
Spongy bone is found inside the marrow cavity
Name the 2 types of ossification
Endochondrial
Intramembranous
Describe the process of endochondrial ossification
- Bone forms as cartilage model
- Blood vessels invade cartilage
- Cartilage replaced with bone
- Cartilage remains in epiphyseal growth plate
- Growth plate eventually ossifies
Describe the process of intramembranous ossification
- Mesenchymal cells develop into osteoprogenitor cells that mature into osteoblasts that start to deposit bone
- Residual mesenchymal cells develop blood vessels and bone marrow
Note: no cartilage model and this bone formation also occurs in adult bone
Name the two types of bone growth
Appositonal
Interstitial
What is the difference between the types of bone growth
Appositional growth is growth in diameter of a bone
Interstitial growth is growth along the length of a bone
What is A?
Epithysis
What is B?
Articular cartilage
What is C?
Epithyseal line
What is D?
Spongy bone
What is E?
Medullary cavity
What is F?
Nutrient foramen
What is G?
Endosteum
What is H?
Periosteum
What is I?
Articular cartilage
What is J?
Diaphysis
What is A?
Periosteum (membrane covering bone)
What is B?
Cortical (hard) bone
What is C?
Trabecular (spongy) bone
What is D?
Articular cartilage
What is E?
Epithyseal plate
What is F?
Medullary cavity
What is G?
Marrow
What is H?
Blood vessels
How to bones increase in width?
Bones increase in width by appositional growth, new bone added from outside onto existing bone
How do bones increase in length?
Bones increase in length by interstitual growth, occuring by cell division in the epithyseal growth plate within the bone
What is this a diagram of?
Hyaline cartilage
What is A?
Chondrocytes
What is B?
Matrix
What is C?
Lacunae
What is this a diagram of?
Spongy bone
What is A?
Trabecular bone
What is B?
Yellow bone marrow (adipose tissue)
What is this a diagram of?
Compact bone
What is A?
Lacuna
What is B?
Lumellae
What is C?
Haversian canal
What is D?
Osteon
What colour does bone show on CT and MRI?
White on CT
Black on MRI
