Bones Flashcards
Functions of the skeleton (6)
support protection movement mineral storage blood cell production fat storage
What is the axial skeleton and what does it include?
Central axis
eg. skull, vertebral column, ribs
What is the appendicular skeleton and what does it include?
Appendages
upper and lower limbs
include shoulders (pectoral girdles) and pelvis (pelvic girdles)
Why do adults have less bones than babies?
bones fuse together as humans grow
What are the 5 different types of bones?
long (with bulbous ends) short flat (eg. sternum) irregular (eg. vertebrae) sesamoid (eg. patella being the only one everyone has)
What are the cells, fibres and ECM present in a bone?
osteogenic cells, osteoblast, osteocyte, osteoclast
collagen (organic)
mineral salts (inorganic)
Anatomy of a long bone: what is the diaphysis?
shaft, compact bone
Anatomy of a long bone: what is the epiphysis?
ends of bone, spongey
Anatomy of a long bone: what is the articular cartilage?
covers epiphyses
Anatomy of a long bone: what is the medullary cavity?
marrow cavity
Anatomy of a long bone: what is the endosteum?
lining of marrow cavity
Anatomy of a long bone: what is the periosteum?
tough membrane covering bone but not cartilage
Function and location of osteogenic cells?
derived from embryonic fibroblasts
undergo mitosis
located at edge of bone
some become osteoblasts
Function and location of osteoblasts?
bone forming synthesis organic bone matrix initiate calcification become osteocytes located at the edge of bone
Function and location of osteocytes?
cytoplasmic ‘fingers’
osteoblasts that have become trapped in the matrix secreted
maintain marrow
located inside cavities in the matrix
Function and location of osteoclasts?
bone dissolving release lysosomal enzymes multinucleate large derived from fusion of bone marrow in monocytes located at edge of bone in pits
What is the inorganic matter in the bone matrix?
calcium phosphate and calcium carbonate salts form crystals (bone is hard)
What is the organic matter in the bone matrix?
collagen fibres for strength and flexibilty
What is mineralization (calcification)?
hardening of matrix when mineral crystals deposit around collagen fibres
What are the two types of bone found within bones?
Compact and spongey
What is the function and location of compact bone?
solid layer located at diaphysis and edges of bone
resist stresses from weight and movement
What is an osteon or Haversian system (compact bone)?
bone matrix laid down in rings around blood vessels
blood vessels run in Haversian canals
osteons align along lines of stress
What is lamellae (compact bone)?
layers of bone
concentric- rings of bone
interstitial- old osteons that have been partially removed
Where are osteocytes found in compact bone and how do they communicate?
found in spaces in matrix called lacunae
communicate with each other via canaliculi
Structure, function and location of spongey bone
latticework of thin plates (trabeculae) orientated along lines of stress
spaces filled with red marrow
located at epiphyses in flat bone
provide strength with little weight
How do osteogenic cells, osteoblasts and osteoclasts receive nutrients?
Near edge of bone near blood vessels
Diffusion
How do osteocytes receive nutrients?
Nutrients cannot diffuse through matrix
Join to each other via cell extensions within canaliculi which allow diffusion
Function and location of red bone marrow
located medullary cavity and trabeculae spaces
development of blood cells
Function and location of yellow bone marrow
located diaphysis medullary cavity
fat storage
Functions of cartilage (3)
resist compression
absorb shock
smooth surface to minimize friction
What are the three cells in cartilage?
chondroblasts, chondrocytes, matrix
What and where are chondroblasts?
secrete cartilage matrix, near edge
What and where are chondrocytes?
chondroblasts trapped within matrix secreted, located in lacunae
What is the cartilage matrix made from?
chondroitin sulphate (retains water so is rubbery)
What are the three different types of cartilage and what characterizes them?
hyaline (articular) cartilage: collagen = elastin
fibrocartilage = more collagen
elastic cartilage = more elastin
Location, function and structure of hyaline cartilage
clear, glassy, fine collagen fibres
over ends of bones at moveable joints to prevent friction
holds airways open, eg. trachea
Location, function and structure of fibrocartilage
row of chondrocytes in lacunae, parallel bundles of collagen
located intervertebral discs
resist compression, absorb shock
Location, function and structure of elastic cartilage
web-like mesh of elastin amongst lacunae
located external ear, epiglottis
flexibility, elastic support, maintain shape
