Active range of motion
Voluntary
Passive range of motion
Involuntary
How are joints classified
By type of material uniting or bonding the articulating bones
What are the three fibrous joints (synarthroses)
Sutures, syndesmosis, gomphosis
What are the two cartilaginous joints (amphiarthroses)
Hyaline (synchondroses)
Fibrocartilage (symohyses)
What are the three synovial joints (diarthroses)
Spheroid
Hinge
Condylar
Movement of fibrous joints
Dependent on the length of the fibers uniting the bones
Why do sutures have little movement
Held together by several layers of strong CT
Extremely tight, LITTLE movement
Suture edge:squamous type
Edges overlap
Suture edges: serrate type
The edges interlock
In syndesmosis, bones are united by a sheet of fibrous tissue. Can be a __ or a __ __
Ligament
Fibrous membrane
Give example of syndesmosis
Interosseous membrane
Ankle syndesmosis
Tympanostapedial syndesmosis
Movement of fibrous syndesmosis
Depends on distance between bones and the degree of flexibility of the uniting fibrous tissue
Gomphosis
Unique joint between tooth and the bone in its alveolus (socket)
Example of gomphosis
Fibrous tissue of the periodontal ligament firmly anchors the tooth
Movement of cartilaginous joints
Small rocking, sliding motion
Another name for hyaline
Synchondroses
Another name for fibrocartilage
Symphyses
Hyaline cartilage is usually a ___ union. What happens later
Temporary bc it permits growth
Later fuses when growth is complete
Epiphyseal plate
Hyaline
Secondary cartilaginous joints
Surfaces of the articulating bones are covered with hyaline cartilage and the bones are united by strong fibrous CT and/or fibrocartilage
Strong slightly movable
Examples of cartilaginous joints
Pubic symphysis
IV discs are fibrocartilage
Synovial joints the the most __ joint
Common
Characteristics of synovial joint
Provide free movement
Why are they called synovial joints
Lubricating synovial fluid
What are synovial joints lined by
Synovial membranes or capsules
Some contain fibrocartilage disc or meniscus
Distinguishing features of synovial joints
Synovial membrane (produces fluid) Joint cavity (contains synovial fluid) Articular cartilage (hyaline-covers ends of bones, aides in reducing friction) Articular joint capsule(usually reinforced with accessory ligaments which are either separate or attached to the capsule
What is articular cartilage. What is its blood supply.
Usually hyaline
NO BLOOD VESSELS or nerve supple
What nourishes articular cartilage of synovial joint if no blood or nerve suply
Synovial fluid which obtain nutrients from capillaries in the synovial membrane
Is the articular capsule vascular
Yup by covered by synovial membrane which is vascular
What is the articular joint capsule
Fibrous capsule that envelops the articulation or joint
Describe the synovial membrane
Vascular ct membrane that lines the entire joint cavity
Does not cover articular cartilage
Produces synovial fluid
Regenerates if damages
Accessory ligament sof the synovial capsule
Either part of their fibrous capsules(intrinsic) or are separate fromt he fibrous capsules (extrinsic)
Limit joint movements in undesireable directions to aid in preventing damage to the joint
Maintain the normal relationship between the articulating bones
Can be injured easily (tears, sprains)
Articular discs of synovial joints
Present where the articulating surfaces are incongruous(articular disc of the wrist)
Usually fibrocartilaginous pads holding bones together
Nerves present only at attached margins
Fibrocartilaginous ring (labrum)
Deepens the articular surface for one of the bones
Ex glenoid labrum of the shoulder joint
Tendons within the capsule of the joint:synovial
Ex-tendon of hte long head of the biceps brachii muscle runs within the capsule of the shoulder joint
How are synovial joints classified
Shape of articulating surfaces and/or type of motion permitted
Plane joints
Numerous and small
Permit gliding or sliding
Opposed bone surfaces flat or almost flat
OST move on onyl one axis (uniaxial)
Movement limited by tight articular capsules
Injuries are relatively common
Example of plane joint
AC, proximal tibiofibular, intercarpal, sc
Hinge joints:synovial
Uniaxial
Strong collateral ligaments
Where are hinge joints
Elbow knee ankle interphalangeal joints
Ball and socket joint: synovial
Multiaxial, highly movable
Spheroidal surface of one bone moves within the socket of another bone
Flexion/extension, ad/ad, medial lateral rotation, circumduction
Example of ball and socket
Hip and shoulder
Pivot joint
Uniaxial joint
Allows rotation
One element rotate on its own axis
Example of pivot joint
AA
Radioulnar
Condyloid and ellipsis joints
Partial flattening of both articular surfaces
Modified spheroid
Example of condyloid and ellipsoid joints
MCP radiocarpal
Saddle joints(sellar)
Biaxial with opposing surfaces shaped like a saddle
Allows extension/flexion ab/ad an d ircumduction
Example of a saddle joint
Carpametacarpal of thumb
Joitns have a rich nerve supply! Nerve endings are found in the articular capsule. What is Hilton’s law
Nerves supplying a joint also supply the muscles moving the joint and the skin covering the attachments of these muscles
Sensation of joints
Proprioception-provides awareness and info concerning the movement, resistance and position of the joint
Pain fibers are numerous int he fibrous capsule and its associated ligaments
Sensory endings response to twisting and stretching
Wolffs law
Bone is increased where needed and reabsorbed where it is not
What can wolffs law explain
Decreased density related to disuse or aging
Increased density hypertrophy related to increase stresses
Cartilage remodeling and adaptation
Trauma or abnormal wear leads to structural disruption of matrix
Loses elasticity therefore increases stiffness
Limited capacity to regenerate or repair
With repeated high stresses can lead to development of degenerative joint disease
Ligaments and tendons remodeling and adaptation
Becomes stronger and suffer with increased stress
Physical training increase number and quality of collagen cross links
Become weaker and less stiff with a reduction of stress
Lose collagen from immobilization and aging
Synovial joints are well designed to withstand wear, but heavy use can cause degenerative changes
. What does this result in
Stiffness , discomfort or pain
Three basic forms of arthritis
Osteoarthritis
Inflammatory
Traumatic
Osteoarthritis
Most common form of arthritis, affecting millions of people worldwide. It occurs when the protective cartilage on the ends of your bones wears down over time
Inflammatory arthritis
Autoimmune
Immune system turns against the body its designed to protect for unknown reasons and causes degeneration of joints
Traumatic arthritis
Occurs following injury, excessive movement or physical trauma such as a penetrating wound. Sports injuries are a common cause of traumatic arthritis
Osteoarthritis
Joint wear
Hips and knees
Supports the weight of the body
Can affect younger people depending on activity
Why is excessive twisting and stretching of the articular capsule very painful
Highly sensitive
Synovial membrane is relatively insensitive
Joint pain is poorly localized
Can be referred to overlying skin or muscle (Hilton’s law)
May be visceral disturbances associated
Fibrillation
Early degenerative change of the articular cartilage due to the loss of proteoglycans
Unmasks collagen fibers and increases water content in chondrocytes
Equivalent of a superficial erosion of the cartilage
Affected cartilage becomes dull with a yellowing discoloration taking a characteristic ground glass appearance
Eburnation
Complete loss of articular cartilage
Accompanied by thickening of the subchondral bone (osteosclerosis)
Exposed bone surfaces take an ivory like appearance
It is a PERMANANT lesion since lost cartilage cant be repaired
Joint degeneration
Joint mice (osteochondromatosis)
-fragments of cartilage and/or bone floating free in synovial fluid
Pieces of degenerating cartilage detachfrom the subchondral bone
Commonly seen in degenerative joint diseases
Particularly in osteochondrosis dissects
Arthroscopy
The cavity of the synovial joint can be examined by inserting a cannula and an arthroscope
What do joitns receive blood from
Articular arteries that arise from the vessels around the joint. The arteries often anastomose (commmunicate) to form networks to ensure a blood supply to and across the joint in the various positions assumed by the joint
Articular veins
Are communicating veins that accompany arteries and are located
Where are the articular arteries and veins located
In the joint capsule , mostly the synovial membrane