Ch 9 Articulations Flashcards
How many joints do we have?
230
what is the correct word for doubled jointed
hypermobility
why do some people’s have more ROM (range of motion)
- abnormally shaped ends of one of more bones in a joint
- weak ligaments (due to differences in protein structures, genetics and/ or hormone levels)
- stretched ligaments due to training
- muscle tone can influence ROM of joints (yoga exercise vs. body building)
What are articulations
where 2 bones (joints) interconnects
what is the function of articulations
function:
- hold bones together
- may allow movement
typically at each joint,
- there is a compromise between the need for strength and the need for mobility
*the joints in skull is very tightly jointed = no mobility
what are the two ways to classify joints?
1) structural classification of joints
- based on the structure holding bones together
a. bony fusion
b. fibrous joint
c. cartilaginous
d. synovial joints
2) functional classification of joints
- based on ROM (range of motion)
a. synarthrosis = immovable (fibrous or cartilaginous, may eventually fuse; bony fusion)
b. amphiarthroses = slightly movable (fibrous or cartilaginous)
c. diarthroses = freely movable (synovial)
What are the types of joints based on functional classification?
- synarthroses (immovable)
a) sutures - fibrous
b) gomphoses (plural) - fibrous
c) synchondroses - cartilaginous
d) synostosis - bony fusion - amphiarthroses (slightly movable)
a) syndesmoses - fibrous
b) symphysis - cartilaginous
c) interosseous membrane - fibrous - diarthroses (freely movable)
a) synovial
Explain what synarthorses is
4 types
= immovable (functional classification of joints)
- fibrous or cartilaginous or bone
a)** sutures **consist of dense fibrous connective tissue
(in skull)
b) gomphoses - fibrous CT e.g. peridontal ligament binds teeth to jaws
- found only between the teeth (anchored intot heir sockets within the bony jaws by peridontal ligaments) and their sockets int he mandibel & maxillae
c) synchondroses : rigid bridge of cartilage between two bones
d) synostoses: totally rigid, two bones fused together so that boundary disappaer e.g. ephyphyseal lines (aka epiphyseal plates)
Explain what is amphiarthroses
= slightly immovable (functional classification of the joints)
- callagen fibers or cartilage
a) syndesmoses: bones connected by a ligament (made of collagen) = it is a fibrous joint
e.g. the end of tibia & fibula
b) symphysis: bones separated by a fibrous cartilage pad e.g. the pubic symphysis of hipbones
c) **interosseous membrane **: a lot of cartilage
e.g. between fibula and tibia
What is diarthroses
= freely movable joints
- synovial joints ; complex structure w/ synovial fluids (in the middle)
a) **articular cartilage **
(function) : to prevent bone-bone contact & reduce friction
- resemble hyaline cartilage BUT no perichondrium
- higher wateer content than normal; synovyal fluid produced
by synovial membrane
b) **joint cavity ** (synovial cavity)
(function): very slippery; lubrication/ shock absorber/ provides nutrients to the cartilage (cell servivals)
c) lining the joint cavity **
- articular capsule
- fibrous layer; continous with periosteum of the articulating bones
- synobial membrane
- outer layer of loose (areolar** CT + incomplete)
-* inner layer *of synoviocytes (fibroust-like synoviocytes) and macrophages that does not extend over the articulating parts of the articular cartilage and menisci
d) synovial fluid - fills cavity (in joint cavity)
- secreted by synociocytes of the inner layer “epithelium”
chemical makeup: similar to interstitial fluid w/ high levels of proteoglycans > clear, viscous solution
(functions)
1. lubrication: reduce friction
2. nutrient distribution: from vessels in synovial membrane areolar tissue
3. shock absorption: distribtues shock evenly across articular surfaces
What is synovial membrane made of?
inner and outer layers
articular (hyaline) cartilage/ synovial fluid are protected by synovial membrane that is made of…
- epithelium = inner layer
- areolar tissue (loose CT) = outer layer
- dense irregular tissue (very strong) = the mostouter layer
what are composed inside the membrane:
- capsule
- capillary
- adipocytes
What are in the articular (joint) capsule?
In the articular (joint) capsule:
- fibrous membrane
- synovial membrane
Types of joints
(functional classification) last review
1. synarthroses (immovable)
- fibrous or cartilaginous or bones
A) sutures: dense fibrous CT between the skull bones
b) fomphoses: fibrous CT peridontal ligament binds teeth to jaws
c) synchondroses: epiphyseal cartilage of long bones
d) synostoses: 2 bones fuse, e.g. epiphyseal lines
2. amphiarthroses (slightly movable)
- collagen fibers or cartilages
a) syndesmoses: ligament between tibia & fibula
b) symphsis: fibrous cartilage pad between vertebrae
3. diarthroses (freely movable)
- fibrous articular capsule containing synovial fluid
a) synovial: ends of long bones
Accessory structures of some synovial joints
1) articular discs, or menisci = wedges of fibrocartilages separating the articular surfaces
2) fatty pads between firbous capsule and synovial membrane
3) ligametns: strengthen and support the joint reinforcement
4) additional lubricating structures:
a. bursae: samll, fluid-filled pockets
b. tendon sheath: similar structures, wrapes around joint to limit & support joints ROM
What is articular discs, or manisci
one of the accessory structures (synovial joints)
= wedges of fibrocartilage separating the articular surfaces
(function): channel the flow of synovial fluid
e.g. knee (to stabilize the joint)
What are fatty pads?
one of the accessory structures (synovial joints)
= between firbous capsule and synovial memrbane or bone
- covered with layer of synovial membrane
(e.g. the knee; provides a place to knee to support the weigh of the body)
(functions):
a) protect articulating surfaces
b) packing material: fill in spaces as joint cavity chanages shape
what are the ligaments?
one of the accessory structures (synovial joints)
- strengthen and support the joint reinforcement (Dense regular CT)
e.g. the arm (anular ligament of the radius/ radial collateral ligament)
what are the additional lubricating structures for the accessory structures of synovial joints?
a) bursae
- small, fluid-filled pockets
b) tendon sheath
- similar structure, wraps around joint to limit & support joint’s ROM
e.g. the end of humerus near to cavicle
- subarcrominal bursa
- coracoacromial ligament, coracohumeral lligament, glenohumeral ligament
What are the factors that stabilize synovial joints?
i.e. keep them in aligment
- articular surfaces “shapes”
- **collagen fibers **of the joints capsule & any ligaments present
- presence of other bones, skeletal muscle, fat pads or cartilage
- tension in tendons & muscle contraction muscle tone = moves bones in a specific direction
What is luxation
= dislocation
- bones come out of alignment
results: can tear the capsule wall making the shoulder more prone to future dislocations
- sensory neruons in joint capusle, ligaments, tendons (but not joint cavity)»_space; sense pain
what are the 5 types of dynamic motions
1.** initial position: pencil at right angles to surface
2. gliding movement: pencil remains vertical, but tip moves away from point of origin
3. angular motion: tip remains stationary, but shaft changes angle relative to the surface
4. circumduction: a type of angular motion; tip remains stationary while the shaft, held at an angle less than 90, describes a comple cricle
5. rotation: with tip at same point, the angle of the shaft remains unchanged as the shaft spins aournd its longitudinal axis
6 kinds of synovial joints
the structual classification of synovial joint
1) ball and socket (hip, shoulder)
2) ellipsoidal/ condyloid (metacarpals to phalnges, mandible to tempral)
3) saddle (thumb)
4) hinge (elbow, phalanges)
*bended forward/ backward
5) pivot (radius to ulna, atlas to axis)
*spine to prone/ vice versa
6) plane/ gliding (writst, ankle, vertebral) only few locations
(interverterbla disc)
What is ball and socket joints?
the motion and location
motion allowed: triaxial
- all combinations of angular & rotational movement
e.g. shoulder/ hip (acetabulum of hip bone/ head of femur)
What is ellipsodial/ condyloid joint
the motion and location
motion allowed: biaxial
- oval end one bone fits into depression of another
e.g. radiocarpal joint, metacarpophalangeal 2-5 (where fingers meet palm)
condyloid joint between radius and scaphoid and lunate bones of carpus
*queen’s hand
