Joint anatomy Flashcards
What are the two things used to classify joints?
- Structure (what holds the joint together? Is there a cavity?)
- Function (how much freedom of movement the joints allow)
What is articulation?
Site where two or more bones meet
What are the subcategories of structure when it comes to the classification of joints?
- Fibrous (absent of joint cavity and held together by dense irregular tissue - collagen)
- Cartilaginous (bones are attached to cartilage allowing for some movement between bones)
- Synovial (most common, most movable, present of a fluid-filled joint cavity that allows movement)
What are the subcategories of function when it comes to the classification of joints?
- synarthroses: no movements; fibrous joint
- amphiarthroses: Little movement; cartilaginous
- diarthroses - synovial joint; freely movable
Fibrous joints - What are the three types of joints and how much movement do they have?
- sutures (No movement)
- syndesmosis (limited movement)
- gomphosis (peg-in-socket)
Fibrous joints - Describe the structure and location of sutures, syndesmosis, gomphosis?
ST: overlapping/ interlocking 2 bones - skull
SD: connected by cord(ligament) and sheet (interosseous membrane - tibia fibula joint)
G: connection is periodontal ligament - tooth embedded in jaw
Cartilaginous joints - What is it and their two subcategories?
Bones United by cartilage with no joint cavity and shock absorption
- synchondroses
- symphysis (flexibility)
Cartilaginous joints - describe the difference between synchondrosis and symphysis when it comes to structure and location?
- synchondroses: Bar or plate of hyaline cartilage - epiphyseal plate and between first 7 ribs and sternum
- symphysis (flexibility): Particular service covered with hyaline cartilage linking to fibrocartilage
- pubic symphysis and intervertebral joints
Synovial joints - describe what it is and the six kinds of synovial joints?
makes up most joints in body (lots of movement) and includes almost all limbs
- articular (hyaline) cartilage
- joint (synovial) cavity
- articular capsule
- synovial fluid
- reinforcing ligament
- Rich nerve and blood vessel Supply
Synovial joints - what is the difference between articular (hyaline) cartilage and joint (synovial) cavity?
AC: Covers opposing bone surface providing cushioning
JC: fluid fields between articulating bones to help with lubrication
Synovial joints - what is the difference between articular capsule and synovial fluid?
AC: Double layered (outer fibrous - strength), (inner synovial - synovial fluid)
SF: Phil’s joint cavity and reduces friction
Synovial joints - What are reinforcing ligaments and the three types?
Restricts movement of joint for stability
- capsular (thickened part of fibrous layer)
- extra capsular (outside the capsule)
- intra capsular (inside capsule but excludes synovial cavity - helps with joint range)
Synovial joints - What is rich nerve and blood supply and their functions?
- Nerve fibers that detect pain and monitor position and stress of joint
- capillary beds provide filtrate for synovial fluid
Synovial joints - what is the functional difference between fatty pads and articular discs?
FP: cushioning (hip/knee joints)
AD: improve fit (knee/jaw joints)
Synovial joints - what is the difference between bursa and tendon sheath?
B: sac lined with synovial membrane and containing a thin file of synovial fluid (ligaments, muscles, skin and muscle tendons - ribs) TS: elongated bursa that wraps around tendon
Synovial joints - What are the three factors that influence stability in these joints ?
- articular surface
- ligaments
- muscle tone
Synovial joints - What is the difference between articular surfaces, ligaments, and muscle tone?
AS: shape doesn’t provide stability since flat (ball and socket help make deeper groove to combat that)
L: more ligament = more strength but can’t stretch more than 6% before damage and scarring
MT: tendons are most important for stabilizing, help maintain alignment
What are the three common joint injuries?
- Sprains: partially torn ligaments that repair itself but slowly (poor blood supply = limited nutrients)
- Cartilage tears: usually in knee and can’t repair itself (avascular = no blood vessels), causes pain and mobility issues
- Dislocation: bone forced out of their normal position at joint, ligament gets stretched
Synovial joints: Angular movement - What is the difference between flexion, extension, abduction, adduction, hyperflexion, and circumduction?
F: decreased angle (bending)
E: increased angle (strengthening)
AB: moving away from midline
AD: movement towards midline
H: extension goes beyond anatomical position (>120)
C: movement is a combination of all movements (circle motion)
Synovial joints: angular movements - Where are the 3 locations of exceptions, when it comes to angular movements?
- gliding of wrist
- flexion, extension and hyperextension of neck
- flexion, extension and hyperflexion of the vertebral column
Synovial joints - What are rotational movements and their locations?
Around central axis
- axial: head and neck
- appendicular: limbs, shoulders, hips
Synovial joints - what are the six special movements?
- pronation (inwards rotation) and supination (outward rotation)
- dorsiflexion (foot towards shin) and plantar flexion (foot away from shin)
- inversion (sole inwards) and eversion (sole outwards)
- opposition (thumb to other fingers)
- protraction (jaw forward) and retraction (jaw backward)
- elevation (jaw up) and depression (jaw down)
Synovial joints - what are the six types of joints?
- Plane
- Hinge
- Pivot
- Condyloid
- Saddle
- Ball and socket
Synovial joints - what is the difference between plane, hinge, and pivot joints?
PL: 2 opposing surfaces, gliding, nonaxial movement: not around an axis (stability with limited movement)
H: flexion and extension, uniaxial: movement around a single axis
PV: insertion into a ring, rotational movement, head turns from side to side
