MS Systems: Joints and Muscles Flashcards Preview

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Flashcards in MS Systems: Joints and Muscles Deck (29):

What are the three types of joints?

+ Fibrous
+ Cartilaginous
+ Synovial


What are the features of fibrous joints?

No movement


What are examples of fibrous joints?

The suture joints of the skill and teeth


What are the features of cartilaginous joints?

+ Very strong
+ No movement


Where are primary cartilaginous joints (synchondrosis) found?

+ Costal cartilage and ribs
+ Epiphyseal plates in growing bones


Where are secondary cartilaginous joints (symphyses) found?

+ Joints of the sternum
+ Intervertebral discs
+ Pubic symphysis


What are features of synovial joints

1. Fibrous capsule
2. Articular cartilage
3. Synovial membrane
4. Intra-articular disc
5. Bursae
6. Synovial sheaths


What are the features of a fibrous capsule?

+ Consist of collagen fibres
+ May be thickened along lines of stress to form ligaments
+ Ligaments restrict movement, protecting the joint from damage (very commonly damaged e.g sprained ankle)
+ Intrinsic ligaments are part of the capsule


What are features of articular cartilage?

+ Hyaline cartilage
+ Creates frictionless surface
+ Poor blood supply


What are features of synovial membranes?

+ Collagenous tissue that lines the fibrous capsule
+ Secretees synovial fluid


What are features of synovial fluid?

+ Consists of hyaluronic acid, lubricin, small no. of phagocytic cells

+ Reduces friction between the articular surfaces:
- alignment of glycoprotein molecules changes with exercise
- exercise decreases viscosity so that lubrication improves (thixotropic)

+ Provides nutrients (and O2) for articular cartilage, removes waste


What are features of intra-articular discs?

+ Meniscus
+ Made of fibro-cartilage
+ Discs found in joints where there are rotatory movements


What are features of bursae?

+ Closed sacs with synovial membrane, lubricated with fluid

+ Found where friction occurs e.g between skin & bone, tendons & bone


What are features of synovial sheaths?

+ Specialised bursae that surround tendons where they are subject to pressure e.g those found in the hand and foot


What are factors that influence joint stability?

+ Shape of bones
+ Strength and position of ligaments
+ Tone of surrounding muscles


What is osteoarthritis?

Degenerative disease:
- articular cartilage
- weight bearing joints


What is rheumatoid arthritis?

Autoimmune disease:
- changes in synovium lead to destruction of articular cartilage


What is the purpose of deep fascia?

It divides the limbs into compartments (e.g in the arm - anterior/posterior

Compartments contain groups of muscles that share a function


What is superficial fascia?

Thin layer of loose fatty connective tissue underlying the dermis and binding it to the parts beneath


What is deep fascia?

Layer of dense connective tissue which can surround individual muscles

Surround groups of muscles to separate into fascial compartments


What are the components of a muscle functional group?

+ Prime mover
+ Synergists


What are features of muscle fibres?

+ Arranged in bundles or fasiculi

Divided into 3 layers:
- epimysium (dense sheath on surface)
- perimysium (lies between fasiculi)
- endomysium (separates the muscle fibres)


What is the role of myosatellite cells?

They give rise to myoblasts, which mature into myocytes


What is antagonistic muscle action?

When a group of muscles oppose the movement of another group - called the antagonists

As one muscle relaxes, the other contract and vice versa


Which type of cartilage never ossifies and where is it found?

Elastic cartilage:
- ears
- tip of nose
- epiglottis


What are features of fibrocartilage?

Forms the tough shock-absorbing discs between the symphyses in the midline of the body (intervertebral discs)


What are features of hyaline cartilage?

+ Forms the laryngeal cartilages, tracheal rings, bronchi and costal cartilages

+ May ossify later in life

+ Cushions the joint (articular) surfaces of bones in synovial joints

+ Hyaline cartilage forms the temporary skeleton of the developing foetus (cartilage model) - gradually replaced almost entirely by bone (ossification)


What are ligaments, and what are their function?

Short band of tough, flexible fibrous connective tissue:
- connects two bones or cartilages or holds together a joint.
- a membranous fold that supports an organ and keeps it in position.


What are tendons, and what are their function?

A flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone