Lecture 4 - Cartilage & Bone Flashcards
What makes up the skeletal system
- > bones - > cartilage - > ligaments - > other supporting connective tissues
What are the main functions of cartilage?
- > support soft tissues (keeps airway open)
- > Articulations (joints; keeps bones from rubbing)
- > Precursor model for bone growth (fetal skeleton stars off as cartilage)
Properties of cartilage
they’re semi-rigid connective tissue
- > avascular
- > flexible/resistant
What kinds of cells make up cartilage? Where do they live?
Chondroblasts - > young cells which produce matrix (brats = hyperactive)
Chondrocytes - > older cells that still produce matrix but are more concerned with matrix mantenace *Both cells live in small spaces called lacunae*
List all types of cartilage
- > hyaline cartilage - > fibrocartilage - > elastic cartilage
Properties of hyaline cartilage
- > lacks significant collagen (present but in small quantity)
- > located in fetal skeleton, ends of bones, trachea, nose
- > weakest of the three
Properties of elastic cartilage
- > made of up elastic fibres
- > position/form able to be influenced; snaps back to original shape
- > found in epiglottis (swallow flap) and external ear
Properties of fibrocartilage
- > densely interwoven collagen fibres which contribute to durability
- > Acts as shock absorbers
- > resists tension in one direction
- > can be found in intervertebral discs and meniscus
Functions of bones
- > support - > protection - > anchors for movement (muscles) - > Hematopoiesis (blood cell production) - > Storage
Properties of Bone
- > primarily connective tissue - > extracellular matrix is sturdy and rigid - > strengthened by calcification (minerals deposited in matrix)
Types of bones
- > long - > short - > irregular - > flat
Properties of long bones
- > have both compact and spongy bone - > longer than wide - > most common bone in body
Properties of short bones
- > Have spongy and compact bone - > roughly as long as it is wide - > ie. patella
Properties of flat bones
- > have compact and spongy bones - > protect underlying structures (ie. cranium protects brain) - > provide muscle attachment sides
Properties of irregular bones
- > odd shapes; can’t fit into any other category - > ie vertebrae, hip bones
Identify A (upper and lower), B and whats in between the two, C, D, G, H and J
A (upper) -> proximal epiphysis
A (lower) -> Distal epiphysis
B -> Diaphysis
In between the epiphysis and diaphysis is the Metaphysis
C - > articular cartilage
D - > periosteum
G - > medullary/ marrow cavity
H - > Endosteum
J - > Epiphyseal (growth) plate
What is the epiphysis and what does it do?
- > the knobby, elongated regions at the ends of a long bone
- > strengthens joints
- > is the attachment cite for tendons/ligaments
What is the metaphysis
- > The section of bone in between the epiphysis and diaphysis.
- > contains epithysial (growth) plate
Functions of articular cartilage
allows bones to glide over one another with very little friction
Articular cartilage also comes together to form joints
What are the different types of bone coverings
- > Periosteum
- > Endosteum
Periosteum
- > covers the external surfaces of bone
- > does not cover articular cartilage (if it did, it would cause friction)
- > acts as anchor for blood vessels and nerves
- > anchored by perforating Sharpey fibres embeded in bone matrix
Endosteum
covers most internal surfaces of bone
Describe each type of bone cell
Osteogenitors: stem cells found in endosteum & periosteum that either produce more stem cells or convert into osteoblasts
Osteoblasts: young cells, form matrix, very mitotic
Osteocytes: maintain the matrix and communicate with osteoblasts to cause further deposit of bone matrix; they’re found in lacunae as they trap themselve in a layer of their own matrix
Osteoclasts: large, multicellular; break down bone & cartilage
What makes up the bone matrix
1/3 organic componants(osteoid) : flexible, resist breaking
- > cells, collagen fibres and ground substance
2/3 inorganic componants: hardness
- > mineral salts of inorganic hydroxyappetite, calcium phosphate and calcium phosphate
