Bone II- bone tissue and structure Flashcards
What is the function of a central canal?
To contain the blood vessels and nerves
What is the purpose of the organisation of trabeculae in cancellous bone?
- resists force in multiple directions
- directs body weight force down diaphysis
What are the two main functions of the lamellae?
- form the shape of the osteon
- collagen fibres within lamellae resist forces
What is an osteogenic cell?
Stem cell that produces osteoblasts
what are Lacunae?
Lakes for osteocytes
What is the Medullary cavity?
The hollow part of bone containing bone marrow
What cell removes and destroys bone matrix?
Osteoclast
What is osteoporosis caused by? What are the results?
OC> OB activity, trabecular in cancellous bone becomes thinner, making bones brittle and likely to fracture
What is the function of an osteon?
provides a pathway for nutrients to get to cells in the ECM
What are longitudinal units within compact bone called?
osteons
What does an osteon contain?
- central canal
- Lamellae
- Lacunae
- Caniculi
Where are osteocytes on cancellous bone
in lacuna between lamellae or on surface of trabeculae
What are Canaliculi?
Channels for nutrients through ECM
What is the function of an osteocyte?
Communication and maintenance- recycles proteins in matrix
What are the inorganic components of bone ECM?
hydroxyapatite + other Ca minerals
What is The hollow part of bone containing bone marrow called?
The medullary cavity
Name the 4 types of cells in the bone?
- osteoblasts
- osteocytes
- osteoclasts
- osteogenic cells
What is appositional growth?
Growth by forming new layers on the surface of pre-existing layers; process of increasing in thickness rather than length.
What are Osteons?
Osteons are longitudinal units within compact bone
What is the function of an osteoclast
removes and destroys bone matrix
How much of bone ECM is organic?
33%
What is Lammellae?
A series of cylinders of ECM around the central canal
What structure does compact bone have that isn’t present in trabeculae/ cancellous bone?
Central Canal
What is Bone Homeostasis
Maintaining a balance of OC and OB activity
what is the name of a cell that produces bone matrix?
Osteoblast
What is the name of a Stem cell that produces osteoblasts?
osteogenic cell
What are the organic components of bone ECM
- collagen (protein)
- Ground substance ( proteoglycans)
What are the benefits of bone homeostasis?
- Allows body to mobilise calcium, phosphate, and other bone. matrix nutrients
- Shape change possible throughout life to resist strain
- allows bone to respond plastically to stress
What do humans have to do to ensure bone homeostasis
- consume adequate calcium
- moderate excersise
How does appositional growth occur in long bones?
- osteoblasts secrete bone matrix to create new layers/ lamellae
- osteoclasts remove bone from medullary cavity to prevent heaviness
What are Trabeculae
Bands or columns of connective tissue forming cancellous bone
What percentage of bone ECM is inorganic?
67%
What is the function of an osteoblast?
produces bone matrix
What fills the cavities between trabeculae?
Bone Marrow
What cell is responsible for Communication and maintenance- recycling proteins in matrix?
Osteocyte
