MS System - Joints & Muscles Flashcards
What is the bone structure in utero ?
Cartilage
What are 2 components of the cartilage model in foetus development ?
Formed by chondroblasts
Reshaped by chondrocytes
Ossification
Replacement of cartilage by bone
Endochondral ossification
Ossification in long bones
Intramembranous ossification
Ossification in flat bones
Primary ossification centre
Diaphysis
Secondary ossification centre
Epiphysis
What are the 3 aspects of bone growth at the epiphyseal plate ?
Bone is laid down in the diaphysis and at the epiphysis.
Bony parts are separated by a plate of cartilage
As long as the plate of cartilage is present and active, bone increases in length.
What are the 5 sites of bone lengthening at the epiphyseal plate ?
Ossification zone
Calcification zone
Hypertrophic zone
Growth zone
Resting zone
How long do fractures take to heal ?
2-4 weeks depending on severity and position of fracture.
What 2 things can inflammation and additional blood flow lead to ?
Callus formation
- Osteoblasts quickly form woven bone
- Disorganised bone is weak as collagen fibres are irregular
Lamellar bone laid down
- Collagen organised in regular sheets
- Strength and resistance
Joint
The place where 2 or more bones meet
Function of joints (4)
Facilitates growth
Holds bones together
TRANSMITS FORCES
Enables movement
Arthro
Joint
Classification of Joints by Movement
Synarthroses
Amphiarthroses
Diarthroses
Synarthroses
immobile/ fixed joints
Amphiarthroses
Limited movement
Diarthroses
Variety of moveable joints
Classification of joints by Soft Tissue structure
Fibrous
Cartilaginous
Synovial
Fibrous Joints
Virtually no movement
Cartilaginous Joints
Limited or no movement
Synovial Joints
A variety of movement
Where are fibrous joints found ?
- Sutures
- Gomphoses
- Syndesmoses
Sutures
Thick connective tissues
composed of type 1 collagen fibres
Gomphoses
Collagen fibres which secure teeth into bone of the tooth socket.
Syndesmoses
Fibrous membrane between adjacent bones e.g. radioulna or tibiofibula
Ligament between radioulna or tibiofibular joints
Interosseous ligament
Where are cartilaginous joints found ?
- Synchondroses
- Symphyses
Where are the synchondroses found ?
Head and shaft of long bones
Found on the rib cage
Found in epiphyseal plates in growing bones
Synchondroses
Primary cartilaginous joint
Has hyaline cartilage
Found on the head and shaft of long bones and the rib cage
Hyaline cartilage
Allows bone growth during adolescence and eventually ossifies.
Symphyses
Secondary Cartilaginous joint
Often occurs in the midline
Hyaline and fibrocartilage - provides limited movement
Where are the symphyses found ?
Pubic Symphyses
Between adjacent vertebrae - (VERTEBRAL COLUMN)
Manubriosternal joint
Synovial Joints
Diarthroses
enables movement
Structure of synovial joints
Fibrous capsule
Filled with synovial fluid
Bones covered with articular cartilage
Function of synovial joints
Frictionless
Load bearing
Withstands compression
Synovial Fluid
Highly lubricating
Reduces friction between articular surfaces
Provides nutrients and O2 for articular cartilage and removes waste.
What does synovial fluid contain ?
Hyaluronic acid rich
Lubricant
Phagocytic cells
Features of Synovial Joints
Articular cartilage
Synovial Membrane
Synovial Membrane
Secretes synovial fluid
Collagenous tissue that lines the fibrous capsule
Ligaments
Dense bands of fibrous connective tissue and collagen.
Connect bones
Function of ligaments
Restrict movement, protecting the joint from damage
Intrinsic ligaments
Within / parts of the fibrous capsule
Extrinsic Ligaments
External to the capsule
Bursae
Closed sacs lined with synovial membrane, lubricated with fluid
Where are bursae found ?
Found where friction occurs
Between skin and bone
Between tendons and joints
Synovial sheaths
Specialised bursae, surround tendons where they are subject to pressure.
Factors influencing Synovial Joint Stability (3)
Articular Surfaces
Ligaments
Muscle Tone
Types of Synovial Joint (6)
plane
hinge
ball & socket
saddle
pivot
condyloid
Tendons
Connect muscle to bone
Superficial fascia
On the surface
Deep fascia
Inside
Separates tissue
Agonist
The prime mover
Synergist
Additional force to prevent undesirable actions
Antagonist
Oppose the movement
Osteoarthritis
Degenerative disease
Weight bearing joints
Reduction in quality of articular cartilage
Rheumatoid arthritis
Autoimmune disease
Changes in synovium lead to destruction of articular cartilage.
