Bone Flashcards
What is the major mechanical function, and the composition of a ligament?
Resist tension
Collagen I
What is the major mechanical function, and the composition of a tendon?
Resist tension
Collagen I
What is the major mechanical function, and the composition of cartilage?
Resist compression
(Resist tension)
Collagen II
Proteoglycan & water
What is the major mechanical function, and the composition of fibrocartilage?
Resist compression
Resist tension
Collagen I
Collagen II
Proteoglycan & water
What is the major mechanical function, and the composition of bone?
Resist compression
(Resist tension)
Collagen I
Mineral hydroxyapatite
What is the major mechanical function, and the composition of synovium?
Lubrication
Mainly cellular
True or false:
Bone is a type of connective tissue.
True
What is Endochondral Ossification?
Fetal skeleton is just cartilage.
Blood vessels invade cartilage.
Cartilage skeleton ossifies to become bone.
True or false:
Some bones take 38 years to fully complete endochondral ossification.
False
Some bones take 25 years to fully complete endochondral ossification
What is Intramembranous Ossification?
What kind of bones form this way?
Mesenchyme becomes bone (no cartilage present)
Cells proliferate and condense
Flat bones usually form this way.
True or false:
The medullary / marrow cavity is the site of production of blood cells in immature animals
True
True or false:
The medullary / marrow cavity is called yellow marrow in immature animals
False
The medullary / marrow cavity is the site of production of blood cells in immature animals, and is called red marrow.
True or false:
Red marrow gets progressively replaced by inactive yellow marrow as we get older
True
What is yellow marrow mainly composed of?
Adipose tissue
What is a diaphysis?
The long cylindrical shaft of a long bone
What is an epiphyses?
The expanded ends of a long bone
List three mechanical functions of bone
Protection
Support other organs
Mobility (system of levers)
List three metabolic functions of bone
Mineral store (especially for calcium and metals) Hemopoiesis/Haematopoiesis Potentially an endocrine organ
Osteoblast functions
Osteoblast features
Bone formation
Synthesising bone matrix
Priming bone matrix for mineralisation
Form epithelioid layer on bone surface
Plump cuboidal cells
Abundant organelles for protein synthesis and secretion
Osteocyte formation
Osteoblasts are engulfed and entombed in bone matrix during apposition - they become osteocytes
Osteocyte functions
Osteocyte features
Maintain junctions with other osteocytes, the bone surface and the vascular supply (relies on its canaliculi to do this)
Regulation of calcium homeostasis
Strain gauge to monitor extent of physical loading
Has one nucleus
Has canaliculi
Osteoclast functions
Osteoclast features
Resorption of bone
Large multinucleate cells (many nuclei)
Unique organelles and distinctive appearance
Ruffled border and clear zone
Lining cells functions
Lining cell features
Guard/maintains bone
Activation of bone remodelling
Co-operate with osteocytes in regulating calcium exchange from bone
They are osteoblasts which have completed their synthetic activity phase (can be reactivated)
Flat
1 nucleus, hard to see
What does the bone matrix consist of?
Collagen I
Bone proteoglycan
Non-collagenous proteins - osteocalcin, osteonectin, osteopontin
Mineral hydroxyapatite (complex calcium phosphate salt)
