112- Wrist Trauma Flashcards
What is the biochemical composition of tendons?
Water = 55% wet weight
Collagen = 80% dry weight
(95% type I)
Elastin <1% wet weight
What is the function of tendons?
Connect muscle - bone
Transmits force Focuses pull Acts as a pulley Act as a spring Holds tendons and joints together High tensile strength
What is the structure of a tendon?
Long collagen spirals
Make up of tenocyte / fibroblast cells
Covered in sheaths (endotendon inside, epitendon on outside)
There is a hierarchical structure: fibron, fibre, subfasicle, fasicle, fibre bundle, tendon.
What is the enthesis?
The bone-tendon junction
What are the proterties at the enthesis?
Fibrocartillage band
More collagen like - more proteoglycans
Dissapates compressive forces
How do you differentiate between the insertion and the origin of a tendon attaching to bone?
Insertion - moves
Origin - doesn’t move, angle stays the same
What is the myotendunous junction? How is it specialised?
Muscle-tendon join
Also hierarchical - muscle and tendons have a continuous flow - increasing the anchoring.
What makes up ligaments?
Water - 60-70% wet weight
Collagen 70-80% dry weight
90% type I, 10% type II
Elastin <5%
What are ligaments?
Dense white fibrillar structures, have a passive stablising role in mechanical functions
- Supply proprioceptive function
What differences are there between ligaments and tendons?
Ligaments = more vascular Ligaments = relatively acellular
What cells make up Ligaments?
Fibroblastic cells
What is an example of a modified ligament?
Articular disks
What is the effect of exercise on tendons and ligaments?
Tendons - Increase collagen fibril size, strenght and stiffness
Ligaments - Increase collagen content, number of fibrils and number of small fibrils
What is connective tissue?
ECM and support cells
eg. collagen, elastin, proteoglycans, glycoprotiens
Which collagen types are fibrillar?
I, II, III, V, XI
