Arthrology Flashcards
Fibrous Joints
1 - Sutures
2 - Syndesmoses
3 - Gomphoses
Suture
- fibrous jt
- held together by tight collagen fibers (dense fibrous CT)
- good congruency
- allows virtually no movement
(i.e. sutures in skull)
Syndesmoses
- fibrous jt
- bound by fibrous collagen fibers
- may allow for little movement or for a lot of movement
- think of them as interosseous membranes
- increased movement (interosseous membrane of antebrachium)
- decreased movement (interosseous membrane of shin)
Gomphosis
- fibrous joint
- teeth to mandible and maxilla
3 Structural Categories of Joints
1 - FIBROUS (sutures; syndesmoses; gomphoses)
2 - CARTILAGINOUS (synchondroses; symphysis)
3 - SYNOVIAL (majority of joints)
based on binding tissues
Hyaline Cartilage Joint
- we will only consider the 1st Rib -> Sternum as a hyaline cartilage joint (1st sternocostal joint)
- Ribs 2-10 are all in fact Synovial joints
Fibrocartilage Joints
- symphysis
- i.e. intervertebral disks; pubic symphysis
Synovial Joint Components
- Synovial Membrane
- Synovial Fluid
- Articular (Hyaline) Cartilage
- Fibrous Joint Capsule
Synovial Membrane
- lines the joint capsule
- sole purpose is to produce synovial fluid
- thin and easily torn
- not a good binding tissue
Synovial Fluid
- lubricant that reduces frictional stress
- texture of egg whites
- nourish the art. cart. since the art. cart. has poor blood supply.
- Needs to be forced into the articular cartilage (via loading)
Fibrous Joint Capsule
- holds the joint/bones together
- if have major ligament injury (i.e. ACL), you almost surely also tear the joint capsule
- composed of dense irregular CT
- think of sock w/ toes cut off to make a sleeve example
Articular (Hyaline) Cartilage
- smooth cartilaginous coverings on end of bones
- reduces compressional stress as it disperses the force over a larger surface area (STRESS = FORCE/AREA)
- Art. cart. is very poorly innervated, but the subchondral bone is very richly innervated. Therefore, if art. cart. doesn’t do its just to reduce stresses on the bone it is very painful (bone on bone)
- it is often the smaller surface area, the the amount of force, that causes the injury (since both relate to stress placed on body)
Intrinsic Ligaments
- originate and insert within the joint capsule
- i.e. ACL/PCL
Extrinsic Ligaments
- originate and insert outside of the joint capsule
- i.e. LCL
Fibrocartilage Pads
- increase congruence
- reduce compressional stress
- i.e. MENISCI
Double Jointed
- excessive mobility
- either less congruency or looser binding tissues that allows for a greater ROM than the average person
Popping/Cracking Knuckles/Joints
- pop is nitrogen bubbles w/in the synovial fluid pop.
- Taking articular cartilage/ligaments to the ends of ROM under stress so it can lead to joint changes over a long period of time
Crepitus
- crackling of articular cartilage that is not smooth.
- (pot holes, pockets, and crevices make noise when sliding against each other or bone spurring when excess bone sliding over each other)
Dislocation
- articular surfaces become disengaged
- subluxation = partial disengagement
- dislocation = complete diengagement
Sprain
- tearing of ligaments and/or joint capsule
Strain
- tearing of muscle and/or tendon
Arthritis
- inflammation of the joint
- not a precise term as the inflammation can be caused by a number of factors
Rheumatoid Arthritis
- systemic disease.
- affects multiple joints of the body.
- thought to be an autoimmune disease where your own body begins to attack the synovial membrane
Osteoarthritis
- much more common.
- specific to individual joints. Not systemic.
- simply arthritis in only one joint.
- can be caused by acute affects or more likely chronic due to overuse or improper loading
Capsular Ligament
- starts as an extension of joint capsule and then extends and connects to an extrinsic attachment
Cartilage Composition
- White Fibrocartilage (labrum, IVDs) = TYPE I COLLAGEN
- Yellow Elastic (ears, epiglottis) = more elastin than collagen compared to white FC
- Hyaline/Articular Cartilage (joints) = Type II Collagen
Tendon Composition
- small cellular vs large matrix
- primarily Type I collagen
- parallel arrangement
Ligament Composition
- fibroblasts = 20%
- Matrix = 80%
- more collagen than elastin
- predominantly Type I collagen
- varied arrangement allows lig to resist in multiple directions
Physiologic Properties of Skeletal Muscle
- IRRITABILITY - determines amt of stim req to stim fiber
- CONTRACTABILITY
- VISCOSITY - internal resistance that limits rate of contraction
- EXTENSIBILITY/ELASTICITY - ability to withstand deformation & recover
*SUMMATION - if a second twitch is produced before a muscle fiber is relaxed, a greater force is produced
Dense Irregular CT
- joint capsules, aponeuroses, bone periosteum
- multidimenesional fiber patter allows for resistance in multiple directions
- tensile strength, but little extensibility
Dense Regular CT
- tendons
- organized w/ parallel fibers and crosslinks
- resist high tensile load & provides some flexibility
Areolar CT
- “Loose”, allows movement in all directions
- unorganized, thin collagen & elastin
- tensile strength & pliability
- skin, jt capsule layers, intermuscular layers, sub-q tissue
Ground Substance
structureless organic gel:
- reduces friction between fibers
- maintains spacing to prevent excess cross linking
- transports nutrients to fibers
Reticulin
- Type III collagen
- temporary during repair
- much weaker than type I
- needs to be stressed during repair to become type I
Bone Composition
- “inorganic component” helps give solid consistency
- minerals: Ca, phosphate crystals
