Chapter 9: Joints Flashcards
What is a joint
a point of contact between:
- 2 or more bones
- cartilage and bone
- teeth and bone
A joint can also be called
articulation and arthrosis
What two ways can joints be classified
- structurally: is there a joint cavity? what type of connective tissue involved.
- functionally: what degree of movement is permitted
3 Structural classification types
- Fibrous (no articular cavity)
- Cartilaginous (no articular cavity)
- Synovial ( have articular capsule)
3 Functional classifications of joints
- Immovable (ex. suture)
- Slightly movable (ex. intervertebral discs)
- Freely moveable ( ex. hip, knee, shoulder)
Fibrous joints
- lacks synovial cavity
- bones are held together with dense fibrous connective tissue (dense irregular connective tissue)
- permit little to no movement
Types of fibrous joints
- sutures:
dense irregular connective tissue immovable to slightly movable - Syndesmoses:
has greater distance between articulating surfaces
slightly movable
Syndesmoses have…
more dense irregular connective tissue than in a suture
Sutures (fibrous joints) description
Articulates bones united by a thin layer of dense irregular connective tissue, found between skull bones.
Sutures (fibrous joints); degree of movement and example
- immovable to slightly movable
- example; coronal suture
Syndesmosis (fibrous joints): description
articulating bones by a varying amount of dense irregular connective tissue; usually a membrane or ligament
Syndesmosis (fibrous joints): degree of movement and example
- slightly movable (bc of slightly longer fibers)
- example: distal tibiofibular joint and interosseous membrane between tibia and fibula (anterior tibiofibular ligament)
Cartilaginous joints
- lacks synovial cavity
- articulating bones held together with cartilage connective tissue
- permit little or no movement
Types of cartilagnious joints
- Synchondroses: connecting material is hyaline cartilage (immovable to slightly movable) - ex; costal cartilage
- Symphyses: connecting material is fibrocartilage (slightly movable) -ex; intervertebral discs
Synchondrosis (Cartilaginous joints); description + degree of movement + example
- connecting material is hyaline cartilage
- immovable to slightly movable
- example: between first rib and manubrium of sternum
Symphysis (cartilaginous joints); description + degree of movement + example
- connecting material; broad, flat disc of fibrous cartilage
- slightly movable
- example: pubic symphysis and intervertebral joints
Synovial joints
- has a synovial cavity
- articulating bones are covered with articular cartilage, held together by ligaments, contain synovial fluid and have a nerve supply and are surrounded by an articular capsule
What ROM do synovial joints permit
large range of movement
Bursae and tendon sheaths can be found at…
many synovial joints
Bursae:
sac like structures filled with synovial fluid that cushion movement of one body part over another
Tendon sheaths:
a tube like bursae that wraps around tendons subject to a great deal of friction
Movements at synovial joints: gliding
movement of relatively flat bone surfaces back and forth and side to side over another; little change in angle between bones
Movements at synovial joints: angular
increase or decrease angle between bones (circumduction)
Movements at synovial joints: flexion
decrease in angle between articulating bones, usually in sagittal plane or an anterior movement at a ball and socket joint
Movements at synovial joints: lateral flexion
movement of the trunk in frontal plane
Movements at synovial joints: extension
Increase in angle between articulating bones, usually in sagittal plane or a posterior movement at a ball and socket joint
Movements at synovial joints: abduction
movement away from the midline of the body, usually in coronal plane
Movements at synovial joints: adduction
movement of bone toward midline, usually in coronal plane
Movements at synovial joints: circumduction
Flexion, abduction, extension, adduction, and rotation in succession (or in the opposite order); distal end of body part moves in circle
Movements at synovial joints: rotation
movement of a bone around the longitudinal axis; in limbs, may be medial (toward midline) or lateral (away from midline)
Movements at synovial joints: special
occurs at specific joints
- Inversion: medial movement of sole
- Eversion: lateral movement of sole
- Dorsiflexion: bending foot in direction of head
- Plantar flexion: bending of foot in direction of ground
- Opposition: movement of thumb across palm to touch fingertips on same hand
Movements at synovial joints: elevation
superior movement of a body part
Movements at synovial joints: depression
inferior movement of a body part
Movements at synovial joints: protraction
anterior movement of a body part in transverse plane
Movements at synovial joints: retraction
posterior movement of a body part in transverse plane
Types of synovial joints
- plane
- hinge
- pivot
- ellipsoid (condyloid)
- saddle
- ball and socket
Structural and functional classification of plane (synovial joint)
- articulated surfaces are flat or slightly curved
- many are biaxial: back- and -forth and side to side movements. Some are triaxial; back&forth, side to side and rotation
Plane (synovial joint) example:
intercarpal, intertarsal, sternocostal and vertebrocostal
Structural and functional classification of hinge (synovial joint)
- convex surface fits into concave surface
- uniaxial: flexion and extension
Hinge (synovial joint) example:
elbow, ankle, and interphalangeal joints
Structural and functional classification of pivot (synovial joint)
- rounded or pointed surface fits into ring formed partly by bone and partly by a ligament
- uniaxial: rotation
Pivot (synovial joint) example:
atlanto-axial and radioulnar joints
Structural and functional classification of ellipsoid/ condyloid (synovial joint)
- oval shaped projection fits into oval shaped depression
- biaxial: flexion - extension, abduction - adduction
Ellipsoid/ condyloid (synovial joint) example:
radiocarpal and metacarpophalangeal joints
Structural and functional classification of saddle (synovial joint)
- articular surface of one bone is saddle-shaped; articular surface of other bone “sits” in saddle
- Biaxial: flexion - extension, abduction - adduction
Saddle (synovial joint) example:
carpometacarpal joint: between trapezium and metacarpal of thumb
Structural and functional classification of ball and socket (synovial joint)
- ball like surface fits into cuplike depression
- Triaxial: flexion-extension, abduction-adduction, rotation
Ball and socket (synovial joint) example:
Glenohumeral and hip joints
Factors affecting contact and ROM of synovial joints
- structure and shape of articulating bones
- Strength and tension (tautness) of the joint ligaments
- Arrangement and tension of muscles
- Contact of soft parts
- Hormones
- Disuse
How does strength and tension (tautness) of the joint ligaments affect ROM of synovial joints
when you extend your knee, the ligaments at the back get tight
How does contact of soft parts affect ROM of synovial joints
forearm contacting the bicep stops it from flexing further
How do hormones affect ROM of synovial joints
Example: relaxin, a hormone release by the placenta and ovaries, increases the flexibility of the fibrocartilage of the pubic symphysis and loosens the ligaments between the sacrum, hip bone and coccyx towards and of pregnancy
How does disuse affect ROM of synovial joints
- Disuse of a joint for an extended period may limit the ROM
- disuse may also result in decreased amount of synovial fluid, diminished flexibility of tendons and ligaments and muscular atrophy
- example: breaking your arm
Temporomandibular joint anatomical components
- articular capsule (ligaments that surround joint)
- articular disc (meniscus), lateral ligament, sphenomandibular ligament, stylomandibular ligament
Movements of temporomandibular joint
- depression
- elevation
- protraction
- retraction
- lateral displacement
- slight rotation
Shoulder joint anatomical components
- articular capsule
- coracohmeral ligament, glenohumeral ligaments, transverse humeral ligament, glenoid labrum, bursae
Movements of shoulder joint
- flexion
- extension
- hyperextension
- abduction
- adduction
- medial and lateral rotation
- circumduction
Glenoid labrum
little line that surrounds the genoid cavity and extends glenoid cavity to fit around the humerus
Rotator cuff injury (glenohumeral joint injuries)
- occurs from wear and tear, aging, trauma, poor posture, improper lifting and repetitive movements
Dislocated shoulder (glenohumeral joint injuries)
- head of humerus becomes displaced from glenoid cavity; damages ligaments, tendons and muscles
Separated shoulder (glenohumeral joint injuries)
- partial or complete tearing of acromioclavicular ligament
Anatomical components of elbow joint
- articular capsule
- ulnar collateral ligament, radial collateral ligament, annular ligament of the radius
Movement of elbow joint
flexion and extension
Ulnar collateral ligament connects
humerus to ulna
Annular ligament of the radius connects
head of radius to ulna
Anatomical components of knee joint
- articular capsule
- medial and lateral patelar retinacula, patellotibial ligament, oblique popliteal ligament, arcuate popliteal ligament, tibial collateral ligament, fibular collateral ligament, intracapsular ligament (ACL and PCL), articular discs, bursae
Movements at knee joint
- extension
- flexion
- slight medial and lateral rotation
What does ACL prevent
prevents hyperextension as it gets taught during extension
What happens to PCL when flexed
PCL becomes taught during flexion
Suprapatellar bursae prevents friction between
femur and quadriceps tendon
Medial patellar retinaculum does what
it is additional connective tissue that is used to stabilize the knee joint
The arcuate popliteal ligament connects what 2 bones
connects femur to fibula
Affects of aging on joints
- decreased production of synovial fluid
- thinning of articular cartilage
- loss of ligament length and flexibility
Partial hip arthroplasty
replacing part of the femur, does not involve acetabulum
Total hip arthroplasty
replace acetabulum (fossa) of hip bone - install artificial acetabulum
Rheumatism
any painful disorder of the supporting structures of the body - bones, ligaments, tendons, or muscle - that is not caused by infection or injury
Osteoarthritis
degenerative joint disease in which joint cartilage is gradually lost
Rheumatoid arthritis
an autoimmune disease in which the immune system of the body attacks its own tissues (cartilage and joint linings)
Gouty arthritis
Excessive amounts of uric acid that are not able to be excreted
- mostly affects the joints of the feet
Lyme disease
- ticks that rashes to develop and cause joint stiffness
Sprain
- twisting of a joint that stretches or tears its ligaments but does not dislocate bones
Strain
stretched or partially torn muscle or muscle and tendon
Tenosynovitis
inflammation of the tendons, tendon sheaths, and synovial membranes surrounding certain joints
- most often wrist, shoulders, elbows, feet, ankles, fingers