LECTURE 9 Flashcards
1
Q
Describe the general trends in range of motion of particular articulations in relation to the strength of a particular joint.
A
- The more moveable a joint is, with greater ROM, the weaker it is. The less moveable, the stronger/more stable.
- General trend is that strongly reinforced joints tend to be relatively inflexible, and have low ROM. Highly mobile joints (greater ROM) are weaker and more likely to be injured.
2
Q
Which joint is the most moveable joint in the body?
A
glenohumeral joint (shoulder joint)
This joint is weak/easily injured. It is common to dislocate the shoulder
3
Q
2 methods for classifying (categorizing) articulations
A
- STRUCTURALLY (anatomically) - how the adjacent bones are bound to each other
- FUNCTIONALLY (physiologically) - how the joints function in their movement
4
Q
- Aka synostosis (singular) or synostoses (plural). A gap between two bones ossifies, forming one bone. Starts as a fibrous or cartilaginous joint that ossifies.
- There are no subclasses of this joint type.
- Exceptionally strong joint, one of the strongest in the body.
- Immovable
- Examples: left & right mandibles in infants, left and right frontal bones in infants, left and right parietal bones in seniors, first rib and sternum later in life, conversion of epiphyseal plates to epiphyseal lines
A
bony joints
5
Q
- Aka synarthroses (plural). Collagen fibers span the gap between two bones, and penetrate each. Dense regular connective tissue.
- Three types:
- sutures (skull sutures)
- gomphoses (teeth fitting into alveoli of maxillary and mandible bones)
- syndesmoses (interosseous membrane between radius and ulna allow for pronation and supination of forearm, distal tibiofibular joint). - Sutures connect the skull bones and are relatively strong. Gomphoses are relatively strong. Syndesmoses are medium strength.
- Sutures connect the skull bones and are relatively immobile. Gomphoses are relatively immobile, but allow for a light amount of movement to enhance our senses of how dense an object is that we are chewing or something is stuck between our teeth. Syndesmoses are a slightly more moveable type of fibrous joint due to longer collagen fibers.
TEETH ARE NOT BONES
A
fibrous joints
6
Q
- Aka amphiarthroses. Two bones linked by cartilage.
- Two types:
- symphyses (where a pad of fibrocartilage joins two bones - intervertebral discs and the pubic symphysis. Body of vertebrae have articular hyaline cartilage that blends with fibrocartilage discs)
- synchondroses (formed when the gap between two bones is spanned by hyaline cartilage). Between the first rib and the sternum in early life, other rib joints are synovial. Between the diaphysis and epiphysis of a long bone (epiphyseal plates) - going from cartilaginous joint to bony joint. - Slightly less strong than bony and fibrous joints.
- Slightly more moveable than bony and fibrous joints.
A
cartilaginous joints
7
Q
- Aka diarthroses (plural). They possess joint capsules with synovial membranes that produce synovial fluid. Most subject to arthritis and dislocation.
- There are no subclasses of this joint type.
- Weakest of the joint types.
- Freely moveable (relatively speaking), nothing can be 360 due to potential entanglement of blood vessels etc.
A
synovial joints
8
Q
functions of synovial fluid
A
- Lubricates joints
- Transport of gases, nutrients, and metabolic wastes to/from chondrocytes
- Shock absorption
9
Q
- Consists of an inner synovial membrane and outer fibrous capsule.
- Synovial membrane primarily consists of cells that resemble fibroblasts, which secrete synovial fluid.
- Synovial membrane does not cover articular surfaces.
- Outer fibrous capsule is made of dense irregular connective tissue that is continuous with periosteum
A
Joint capsule
(including the synovial membrane) (pertaining to synovial joints)
10
Q
-Hyaline cartilages that covers articular surfaces
- Lack perichondrium
- Cartilages act like a sponge, soaking up synovial fluid (weeping lubrication)
A
Articular cartilages
11
Q
- Incomplete discs of fibrocartilage
- Found in knee
- Improve fit at articulation and channel flow of synovial fluid
- Complete fibrocartilage discs (articular discs) located at temporomandibular joint, both ends of clavicle, and between ulna and carpals
A
Menisci
12
Q
Dense regular connective tissue that connects bones and reinforces synovial joints
- Various types: intracapsular ligaments are inside the joint capsule, extracapsular joints are outside of the joint capsule
- Stretched or torn ligament is known as a sprain. Heals slowly due to minimal vascularity. Bones often break before ligament and will heal much quicker.
A
Ligaments
13
Q
- Attach muscle to bone
- Not part of articulation, but often located around a joint, and thus stabilizing it.
A
Tendons
14
Q
Fibrous connective tissue capsule line with synovial membrane. Filled with synovial fluid. Can be connected to or separate from the joint cavity. Act as ball bearings, reducing friction between ligaments, tendons, muscles, and bone
A
Bursae
15
Q
- Think of them like elongated bursae
- Wrap around tendon like a bun around a hot dog
- Prevalent in hands, feet, wrist and ankles. Lots of articulations in a small/tight area
A
Tendon Sheaths
