Histology Bone Flashcards
What is the definition of a lacuna?
Space containing a cell
Lacunae are found within the Haversian system and contain osteocytes.
What does the prefix ‘osteo’ relate to?
Bone
This prefix is commonly used in terms related to bone structure and function.
What are the functions of periosteum?
Outer condensed collagen layer, important in fracture healing
The periosteum is absent at articular surfaces and at points of tendon and ligament insertion.
What is the main role of osteoblasts?
Synthesis, deposition, and mineralisation of bone matrix
Osteoblasts are cuboidal cells that secrete proteins for bone formation.
What is the term for the attachment site of tendon or ligament?
Enthesis
This site is critical for the connection between muscles and bones.
Fill in the blank: The site of erosion by osteoclasts is called a _______.
Resorption bay
Also known as Howship’s lacuna.
What type of bone provides strength and rigidity?
Compact/cortical bone
This type of bone is found in the shaft of long bones.
What is the function of trabecular/spongy/cancellous bone?
Provide support while minimizing weight
It is found in the epiphysis and vertebral bodies.
What is the Haversian system?
Bony tubes that lie parallel to each other along the long axis of the bones
Also known as osteons.
What does the endosteum line?
Medullary cavity, Haversian canals, and trabecular bone
It plays an important role in calcium homeostasis.
What is the primary mineral in bone?
Hydroxyapatite microcrystals
These contribute to the hardness and strength of bones.
What is the process of bone formation called?
Ossification
It occurs through intramembranous and endochondral ossification.
What is the key difference between intramembranous and endochondral ossification?
Intramembranous involves direct formation from mesenchymal stem cells, while endochondral uses a cartilage template
Examples include skull bones for intramembranous and long bones for endochondral.
What is the role of osteoclasts?
Degrading and remodelling bone during growth
Osteoclasts are polymorphic cells responsible for bone resorption.
What are Volkmann’s canals?
Channels that interconnect Haversian canals
They connect with medullary and periosteal vessels.
What are the three types of joints?
Fibrous joints, cartilaginous joints, synovial joints
Synovial joints are movable and include structures like articular surfaces and synovial membranes.
True or False: Trabecular bone has an osteon arrangement.
False
Trabecular bone does not have Haversian canals; nutrition is through canalicular diffusion.
What is the significance of Sharpey’s fibers?
Connect periosteum to underlying cortical bone
They are important for stability and support.
What is the composition of extracellular matrix in bone?
10-12% water, collagen type I, hydroxyapatite microcrystals
The mineralization of new osteoid is gradual and takes about 3-4 weeks.
