Week 2 Flashcards
Bone tissue type:
Connective
% of bone that is organic
33%
%of bone that is inorganic
67%
Organic component made up of:
Collagen and ground substance (proteoglycans)
Inorganic component made up of:
Hydroxyapatite and other Ca minerals (mineral salts)
Osteogenic cells
Stem cells that become osteoblasts
Osteoblasts
Produce new bone matrix
Osteocytes
Recycle proteins and minerals from matrix, communicate
Osteoclasts
Remove bone matrix
Lamellae
Layers of ECM. Contains collagen fibres
Foramina in compact bone for:
Blood supply
Osteons
Lengthwise units in compact bone
Osteons
Lengthwise units in compact bone
Central canal
Inside Osteons, contains blood vessels and nerves
Lacunae
Lakes for osteocytes
Trabeculae
Columns/tubes of lamella bone in cancellous bone
Cortical bone
Compact bone
Foramina (cancellous)
Gaps between trabeculae containing marrow
Proteoglycans
Long chains of polysaccharides attached to a core protein. Retains water
Periosteum
Covering for bones
Institutional lamellae
Partially absorbed remnants of Osteons
Osteoporosis risk factors
Low calcium, exercise.
High salt, alcohol, and smoking.
Bone homeostasis
Maintaining the balance of OB and OC activity to maintain bone mass
Bone turns to cartilage
Endochondral ossification
Which part of the bone ossifies first?
Diaphysis
Steps of ossification:
- Calcification
- Blood vessels and osteoblasts enter
Layer of cartilage between diaphysis and epiphyses:
Growth/epiphyseal plates
Two types of cartilage in joints:
Hyaline (articular) (main type)
Fibrocartilage
Hyaline (articular) cartilage:
Resists compression, removes friction
Hyaline (articular) cartilage is made of:
a lot of water, not many collagen fibres
Hyaline (articular) cartilage is found:
Moulded to articulating surfaces of bones
Fibrocartilage:
Resists compressions and tension, shock absorbs, deepens articular surfaces
Fibrocartilage is made of:
Many collagen fibre bundles (aligned with stresses)
Ligaments connect:
Bone to bone
Ligaments restrict movement in which direction?
Away from themselves
Bony congruence
Sum of bone surfaces that form an articulation
Fibrous joints movement capability:
Least
Cartilaginous joints movement capability:
Middle
Sunovial joints movement capability:
Most
Bones grow wider
Appositional growth
Cartilaginous model
Temporary cartilage framework that is replaced by bone
Circumferential lamellae
Lamellae surrounding bone
DFCT
Dense fibrous connective tissue
DFCT makes up:
Ligaments, tendons, and joint capsules
DFCT is made of:
Tightly packed collagen fibres and some elastin fibres.
Also contains fibroblasts.
DFCT is designed to:
Resist tension
Fibroblasts
Cells that create and maintain connective tissues
Chondrocytes
Make cartilage ECM
Chondrocytes are found:
In lacunae in cartilage
Avascular
No blood vessels
Cartilage is avascular/not avascular
Avascular
Nutrients enter cartilage via
Joint loading. Pushed in when body moves
Tendons connect:
Bone to muscle
Tendons have more/less elastin than ligaments
Less
Elastin
Stretchy protein
Fibrous joints made of:
Ligaments made of DFCT
Cartilaginous joints made of:
Fibrocartilage
Synovial joints are made of:
Hyaline (articular) cartilage
ROM
Range of movement/motion
Joint capsule outer layer made from:
DFCT, stops leakage
Joint capsule inner layer made of:
Synovial membrane - thin layer of cells.
Joint cavity
Space inside joint capsule, allows for movement
Synovial membrane functions
Holds nutrients for joint loading
Helps frictionless movement
Secretes synovial fluid
Synovial fluid
Fills joint cavity and lubricates joint
Capsular ligaments
Thick parts of joint capsule where more support is needed. Not all synovial joints have these.
Eg. of capsular ligaments
Collateral ligaments of knee:
Medial collateral ligament (MCL)
Lateral collateral ligament (LCL)
Medial collateral ligament (MCL)
Connects femur to tibia, restricts abduction
Lateral collateral ligament (LCL)
Connects femur to fibula, restricts adduction
Intracapsular ligaments
Ligaments inside capsule. Only some joints have these.
Eg. of intracapsular ligaments
Anterior cruciate ligament (ACL)
Posterior cruciate ligament (PCL)
Anterior cruciate ligament (ACL)
Anterior of tibia to posterior of femur.
Restricts posterior displacement of femur
Posterior cruciate ligament (PCL)
Posterior of tibia to posterior to anterior of femur.
Restricts anterior displacement of femur
Fibrocartilaginous pads
Fill in space
Provide shock absorption
Deepen articulations
Only found in some joints
Eg. Of Fibrocartilaginous pads
Menisci (plural) in knee that provides shock absorption and stability
Plane
Multiaxial
Hinge
Uniaxial
Pivot
Uniaxial
Condylar
Biaxial
Ellipsoid
Biaxial
Saddle
Biaxial
Ball and socket
Multiaxial