Joints Part 2 (Synovial Joint)
Ligaments (in many, not all)
- collagenous fibers binds bones - adds joint stability intracapsular - inside synovial cavity extracapsular - extend bone to bone outside capsule
Fat pads:
- superficial to the joint capsule - protect articular cartilages
Shoulder- acromioclavicular Gliding/Planar Biaxial joints
Acromion of scapula and clavicle gliding and rotation of scapula on clavicle
Fingers- interfalangeal Hinge joint
Adjacent phalanges proximal & distal uniaxial; flexion, extension of fingers
5 Components of Synovial Joint
Articular cartilage Joint Cavity Articular capsule (Fibrous & Synovial membrane) Synovial fluid Ligaments
Ball-and-Socket Joints only multiaxial joints in the body
Ball-and-Socket Movement in all planes, as well as rotational movement around a central axis. head fits within a cuplike depression Ex: (shoulder) head of humerus into glenoid cavity of scapula (hip) head of femur into acetabulum of hip bone Type: only multiaxial joints in the body
Condyloid (ellipsoid) Joints Biaxial (2 AXIS) joints
Condyloid Variety of movement in different planes, but rotational movement is possible. Oval convex surface fits into similarly shaped depression flex/ext, around transverse/longitudinal axis Ab&Adduction, curcumduction-round antero-posterior axis. Combination of these movements produces Circumduction. Typical rotation around a third vertical axis does not occur. Ex. radiocarpal joint of the wrist metacarpophalangeal (Knuckle Joints) joints at the bases of the fingers
Menisci (aka articular disc)
Fibrous cartilage pad some synovial joints (e.g. knee) absorbs shock, guides bone movements
Gliding/Planar Biaxial joints
Gliding Sliding back and forth motion only Ex: Intercarpal (wrist) and intertarsal joints (ankle) articular processes of vertebrae acromioclavicular joint (some joints may demonstrate limited rotation) Synovial, Plane/Gliding, Diartotic, Multiaxial
Hinge joint Monaxial (uniaxial) joints
Hinge Flexion and extension in one plane only. One bone with convex surface fits into concave depression Examples: ulna and humerus at elbow joint (trochlea of humerus fits into trochlear notch of the ulna) femur and tibia at knee joint (tibiofemoral) finger and toe joints (interphalangeal) junction of tibia and fibula with the talus (ankle bone).
Hip (coxal) multiaxial
Hip bone and femur flexion, extension, abduction, adduction, rotation, circumduction of thigh
***Other associated Synovial Joint structures:
Menisci (aka articular disc) Bursae Tendons can help stabilize joints
Knuckle-Metacarpophalangeal Condyloid (ellipsoid) Joints Biaxial (2 AXIS) joints
Metacarpal and proximal phalanx Flexion Extension Adduction Abduction Circumduction, Wrist MCP and MTP joints
Foot-Metatarsophalangeal Condyloid (ellipsoid) Joints Biaxial (2 AXIS) joints
Metatarsal and proximal phalanx biaxial; flexion, extension, abduction, adduction, circumduction of great toe
Axis of motion:
Nonaxial - gliding/slipping movements only Uniaxial - 1 plane movement Hinge, Pivot Biaxial - 2 planes movement Condyloid, Saddle joint Multiaxial - 3 planes movement Ball and Socket
Pivot Monaxial (uniaxial) joints
Pivot Rotation around a central axis only. One bone rotates on its longitudinal axis relative to the other Ex: proximal radioulnar joint; the radius pivots during pronation and supination atlantoaxial joint (dens of axis to atlas);
Synovial Joints
Planar/Gliding Hinge Pivot Condyloid Saddle Ball-and-Socket
Wrist-Radiocarpal Condyloid (ellipsoid) Joints Biaxial (2 AXIS) joints
Radius and proximal carpals flexion, extension, abduction, adduction, circumduction
Ribs-Sternocostal Gliding/Planar Biaxial joints
Rib 1 no movment Sternum and ribs 2-7--gliding
Saddle Joint Biaxial
Saddle Variety of movements. Features: Each articular surface is shaped like a saddle, concave in one direction and convex in the other bone (like a sitting rider) Examples: trapeziometacarpal joint at the base of the thumb Type: Biaxial joint (see demo below) Demonstration: A) frontal plane (palmar abduction) B) sagittal plane (opposition)
Shoulder (glenohumeral) multiaxial
Scapula and humerus Synovial flexion, extension, abduction, adduction, circumduction, rotation of humerus
Sternoclavicular Saddle Joint Biaxial https://www.youtube.com/watch?v=CXAIhJPJVgI
Sternum and clavicle multiaxial (allows clavicle to move in all axes)
Temporomandibular Hinge
Temporal bone of skull and mandible uniaxial rotation; slight lateral movement, elevation, depression, protraction, and retraction of mandible
Ribs-Vertebrocostal Gliding/Planar Biaxial joints
Vertebrae (transverse processes or bodies) and ribs gliding of ribs
Shoulder-Acromioclavicular Gliding/Planar Biaxial joints
acromioclavicular joint
Vertebrae-Intervertebral Gliding/Planar Biaxial joints
articular processes of vertebrae
Vertebrae-Intervertebral Gliding/Planar Biaxial joints
between articular processes of vertebrae
Atlanto-occipital (bone of skull and atlas) Condyloid
biaxial; flexion, extension, lateral flexion, circumduction of head on neck
synovial joint's range of motion is limited
by the shape of the articulating bones, ligaments, tendons, the joint capsule, and by muscles that span the joint.
Articular hyaline cartilage
covers ends of articulating bones -- absorbs compression -- synovial fluid: lubricates surfaces
Synovial Joints
diarthrotic (freely moveable) joints encased by joint capsules that contain joint (synovial) fluid.
Joint Articular Capsule
encloses synovial Joint & synovial cavity 2 layers: Fibrous & Synovial Membrane adds stability
Knee-tibiofemoral Hinge joint knee
femur and tibia at knee joint biaxial; flexion, extension of leg,
--fibrous capsule (External - Part of Articular Capsule)
fibrous tissue on outer synovial membrane
Bursae
flat Synovial sacs decreases friction where tendons, muscles, ligaments overlie
Thumb Carpometacarpal of digit 1 (thumb) Saddle Joint Biaxial
flexion, extension, abduction, adduction, circumduction, opposition of metacarpal 1
Synovial fluid
fluid secreted by synovial membrane nourishes/lubricates articular cartilage helps absorb shock
Foot-Intertarsal Gliding/Planar
inversion and eversion of foot
Wrist-Intercarpal Gliding/Planar Biaxial joints
joints between carpal bones of wrist
Ankle- talus Hinge @ ankle
junction of tibia and fibula with the talus (ankle bone). uniaxial; dorsiflexion, and plantar flexion of foot
--Synovial membrane (Internal - Part of Articular Capsule)
lines joint capsule secretes synovial fluid into synovial cavity
Vertebrae of neck-Atlantoaxial Pivot https://www.youtube.com/watch?v=txNeMCrZ-Sk
second vertebrae of the neck piviot joints uniaxial; rotation of the head
Toe's interphalangeal Hinge
toe joints uniaxial; flexion; extension of toes
Elbow-ulna and humerus Hinge joint
trochlea of humerus fits into trochlear notch of ulna uniaxial; flexion, extension of forearm
Elbow Radioulnar (proximal) Pivot
uniaxial convex head of ulna rotates in ulnar notch of radius radius pivots during pronation and supination
Tendon Sheath
when elongated bursae wraps around tendon
