CH 8 - Joints & Movement Flashcards
Articulation
Site of bone-to-bone connection
Arthrology
The study of joints
What is the relationship between joint strength and mobility?
Inversely proportional
Range of motion (ROM)
The amount or degree of movement
What are structural classifications based on?
The anatomical organization of the joint
What are functional classifications based on?
The range of motion of the joint
*Further divided based on anatomical structure
What are the three types of structural classifications?
Fibrous, cartilaginous, and synovial
What are the 4 subtypes of fibrous joints?
Sutures, gomphosis, syndesmosis, and interosseous membranes
Suture
The joint that exists only between the skull bones, interlocked by sutural ligaments (dense fibrous CT)
Gomphosis
A joint that binds teeth to their alveoli with periodontal ligaments (dense fibrous CT)
Syndesmosis
A joint connecting bones with a cord or band of dense fibrous CT
Interosseous membrane
A subtype of syndesmosis where the dense fibrous CT connecting bones is in the form of a thick sheet
What are the 2 subtypes of cartilaginous joints?
Synchondrosis and symphysis
Synchondrosis
A rigid, hyaline cartilage bridge between two articulating bones
Symphysis
A pad of fibrocartilage between two articulating bones
What are the 6 subtypes of synovial joints?
Hinge Ball-and-socket Pivot Plane (gliding) Saddle Ellipsoid (condylar)
Synostosis
A completely immovable joint without a joint cavity in which the joint or cartilage ossifies
What are the three types of functional classifications?
Synarthrosis, amphiarthrosis, and diarthrosis
Synarthrosis
An extremely strong, immovable joint with no range of motion
*Bony edges may interlock or fuse to prevent movement
Amphiarthrosis
A strong, slightly moveable joint with little range of motion
Diarthrosis (synovial joint)
A freely moveable joint, typically at the ends of long bones
*Weakest type of joint
What are the 4 subtypes of a diarthrosis? How are they divided?
Nonaxial, monaxial (uniaxial), biaxial, triaxial (multiaxial)
Divided by the nature/plane of their movement
Describe the movement in a nonaxial (translational) plane.
Gliding back-and-forth & side-to-side movement
Describe the movement in a monaxial (uniaxial) plane.
Movement along one axis, either angular or rotational
Describe the movement in a biaxial plane.
Movement along two axes
*Two or more angular movements but NOT rotational
Describe the movement in a triaxial (multiaxial) plane.
Movement along three axes with angular and rotational movement
What are the 4 features that all diarthroses (synovial joints) have?
Articular cartilage, a joint (articular) capsule, a joint (synovial) cavity, and reinforcing accessory structures
Describe the articular cartilage of a diarthrosis.
Hyaline cartilage that covers the ends of the bones forming the joint
- No perichondrium
- More watery matrix
Describe the joint (articular) capsule of a diarthrosis.
A sleeve enclosing the joint surfaces that is continuous with the periosteum of the articulating bones
- Inner synovial membrane made of synoviocytes, areolar CT, and elastic fibers
- Outer fibrous membrane made of dense collagenous CT
Describe the joint cavity of a diarthrosis.
A space enclosed by the joint capsule that contains a thin film of synovial fluid
What is synovial fluid?
A lubricating fluid for joints that resembles interstitial fluid but with a high concentration of proteoglycans
What are the 3 primary functions of synovial fluid?
Lubrication, nutrient distribution, and shock absorption
List the reinforcing accessory structures of a diarthrosis.
Pads of cartilage or fat Tendons Tendon sheaths Bursae Ligaments Sensory nerve and blood vessels
What is a fat pad?
Localized masses of adipose tissue, found superficial to the joint capsule, that protect articular cartilage and act as packing material for the joint
Meniscus
A pad of fibrocartilage
What are the functions of a meniscus?
Shock absorption
Improve fit between articulating surfaces to stabilize the joint
Weight distribution over a greater contact surface
Proprioceptors
A sensory receptor that monitors position, movement, and stretch of the muscle and joint
Sprain
A condition where the ligament is stretched to the point where some or all of the collagen fibers are torn
Bursa
A small, flat pocket of synovial fluid that lessens friction between rubbing surfaces
*Inner synovial membrane, outer fibrous membrane
Tendon sheaths
Elongated bursa that wraps completely around a tendon
*Inner synovial membrane, outer fibrous membrane
Luxation
A complete dislocation in which articulating bones are forced out of position, damaging articular cartilage, ligaments, and the joint capsule
Subluxation
A partial dislocation
Describe gliding (linear) structure and movement.
Articulating bones move linearly, slipping past each other
*Back/forth, side-to-side
Describe angular structure and movement.
*
Articulating bone can change the angle that pivots at the point of articulation
- Flextion, extension, hyperextension
- Abduction, adduction
- Circumduction
Describe rotational structure and movement.
Articulating bone can spin at the point of articulation around its longitudinal axis
*Not a complete 360°
Flexion
Angle decreases between articulating bones
Extension
Angle increases between articulating bones
Hyperextention
Extension past the anatomical position
Abduction
Movement away from the midline of the body along frontal plane
Adduction
Movement towards the midline of the body along frontal plane
Circumduction
A special type of angular movement
- The hand traces a circle while the shoulder traces a cone
- Not rotation
Rotation
Direction of rotation from anatomical position relative to the longitudinal exis of the body
- Left or right
- Medial (rotation towards axis)
- Lateral (rotation away from axis)
Pronation
Position in which the palms face posteriorly
Supination
Position in which the palms face anteriorly (anatomical position)
Inversion
Twisting the sole of the foot medially
Eversion
Twisting the sole of the foot laterally
Dorsiflexion
Flexion at the ankle (lifting toes)
Plantar flexion
Extension at the ankle (pointing toes)
Opposition
Moving the thumb towards the palm (grasping)
Reposition
Moving the thumb back to anatomical position
Protraction
Moving anteriorly in the horizontal plane (pushing forward)
Retraction
Moving posteriorly in the horizontal plane (pulling back)
Elevation
Movement in the superior direction
Depression
Movement in the inferior direction
Lateral excursion
Mandible moves the the right or left
Medial excursion
Mandible returns to the midline
Describe the movement of a plane (gliding) joint.
Flattened/curved articulating surfaces that slide across each other slightly (nonaxial)
Describe the movement of a hinge joint.
Angular movement in one axis (monaxial/uniaxial)
Describe the movement of a pivot joint.
Rotational movement in one axis (monaxial/uniaxial)
Describe the movement of an ellipsoid (condylar) joint.
Oval articular face within a depression allowing for angular movements around two axes (biaxial)
*No rotation
Describe the movement of a saddle joint.
Concave-convex articulation allowing for angular movement around two axes (biaxial)
*No rotation
Describe the movement of a ball-and-socket joint.
Round head of one bone with a cup-shaped depression in another allowing for all combinations of angular and rotational movements (triaxial/multiaxial)
Glenoid labrum
A ring of fibrocartilage in the socket of the shoulder joint that deepens the socket
List the muscles of the shoulder (rotator cuff).
Supraspinatus
Infraspinatus
Subscapularis
Teres minor
List the joints of the elbow.
Humeroulnar joint (hinge) Humeroradial joint (hinge) Proximal radioulnar joint (pivot)
List the ligaments of the elbow.
Radial collateral ligament
- stabilize lateral surface
Ulnar collateral ligament
- stabilize medial surface
Radial annular ligament
- bind head of radius to ulna
Acetabular labrum
A ring of fibrocartilage in the socket of the hip joint that deepens the socket
List the ligaments of the hip.
Iliofemoral Ischiofemoral Pubofemoral Transverse acetabular Ligamentum teres
List the ligaments of the knee.
Patellar ligament 2 popliteal ligaments Anterior cruciate ligament Posterior cruciate ligament Medial (tibial) collateral ligament Lateral (fibular) collateral ligament
Arthritis
A general term that encompasses all the rheumatic diseases that affect synovial joints
*Always includes articular cartilage damage
Osteoarthritis (OA, degenerative arthritis, degenerative joint disease)
Most common form of arthritis in people 60+
Slow, irreversible, chronic degenerative condition that can result from cumulative wear and tear, genetic factors, earlier joint injury, or obesity
Rheumatoid arthritis (RA)
An inflammatory disorder or autoimmune disease that usually occurs in ages 40-50
Symmetrical restricted joint movement and pain with flare ups and remissions
Pannus
Inflamed synovial membrane
Ankylosis
Immobility due to the fusion of bones
Gouty arthritis (gout)
An accumulation of uric acid crystals (from purine metabolism) within the synovial joint
Pain and inflammation that usually affects a single joint
Rheumatism
A general term that indicates pain and stiffness of the joints
What are the 3 C’s of knee injuries?
Cruciates, collaterals, cartilages
What are 2 examples of synostosis?
Epiphyseal line
Fusion of frontal bones
What are 2 examples of synchondrosis?
Epiphyseal plate
1st sternochondral joint
What is an example of syndesmosis?
Anterior tibiofibular ligament
What are 2 examples of interosseous membranes?
Between tibia/fibula
Between radius/ulna
What is an example of gomphosis?
Bony sockets in mandible/maxillae
What are 4 examples of symphysis?
Pubic symphysis
Intervertebral discs
Manubriosternal symphyses
Xiphisternal symphyses
What are 6 examples of plane/gliding joints?
Acromioclavicular joint
Claviculosternal joint
Intercarpal joints
Intertarsal joints
Vertebrocostal joints
Sacro-iliac joints
What are 4 examples of hinge joints?
Elbow
Knee
Ankle
Interphalangeal joint
What are 2 examples of pivot joints?
Atlanto-axial joint
Proximal radio-ulnar joint
What are 3 examples of ellipsoid/condylar joints?
Radiocarpal joint
Metacarpophalangeal joints 2-5
Metatarsophalangeal joints
What is an example of a saddle joint?
1st carpometacarpal joint
What are 2 examples of ball-and-socket joints?
Shoulder
Hip
