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Joints - Anatomy & Physiology (view source)
Revision as of 11:38, 18 July 2008
, 11:38, 18 July 2008→'''Synovial Joints'''
=='''Synovial Joints'''==
=='''Synovial Joints'''==
*Articulating joints are separated by a fluid-filled joint cavity, which is bounded by a synovial membrane
*Articulating joints are separated by a fluid-filled joint cavity, which is bounded by a synovial membrane
**Synovial membrane: pink connective tissue sheet, vascular and sensitive
***Can be unsupported (membrane may pouch, allowing remote access), resting on an outer fibrous capsule, or separated from capsule by pads of fat
***No continuous covering of cells
***Where cells exist, they produce lubricant (aminoglycans) of synovial fluid
**Synovial fluid: Nourishes and lubricates [[Joints - normal#Articular cartilage|articular cartilage]]
**Synovial fluid: Nourishes and lubricates [[Joints - normal#Articular cartilage|articular cartilage]]
***Normally in canine joint - 0.01 - 1.0 ml
***Derived from synovial membrane cells and blood plasma
***Normal amount in canine joint - 0.01 - 1.0 ml; possible in equine/bovine: 20-40mL
***Transparent to light yellow (horses)
***Transparent to light yellow (horses)
***Usually very thick due to high hyaluronic acid, forms strands
***Usually very thick due to high hyaluronic acid, forms strands
***Very thin
***Very thin
***Has surface projections - villi
***Has surface projections - villi
*Articular Cartilage covers the articular surfaces
*Articular cartilage covers the articular surfaces
**Usually, this is [[Bones and Cartilage - Anatomy & Physiology#Structure and Function of Cartilage|Hyaline]], although [[Bones and Cartilage - Anatomy & Physiology#Structure and Function of Cartilage|Fibrocartilage]] or fibrous tissue can substitute
**Usually, this is [[Bones and Cartilage - Anatomy & Physiology#Structure and Function of Cartilage|Hyaline]], although [[Bones and Cartilage - Anatomy & Physiology#Structure and Function of Cartilage|Fibrocartilage]] or fibrous tissue can substitute
[[Image:Normal joint cartilage.jpg|right|thumb|100px|<small><center>Normal joint cartilage (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
[[Image:Normal joint cartilage.jpg|right|thumb|100px|<small><center>Normal joint cartilage (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
**Articular cartilage is avascular and insensitive
***Nutrients via diffusion from synovial fluid and nearby vessels (adjoining tissue and marrow cavities)
**Limited response to injury, Little repair capacity
**Limited response to injury, Little repair capacity