Question | Answer |
Enables resistance to crushing, tearing, and other forces | Joints |
Joints are categorized by what 2 features? | Function and Structure |
3 functional classifications of joints | Synarthroses—immovable; common in axial skeleton
Amphiarthroses—slightly movable; common in axial skeleton
Diarthroses—freely movable; common in appendicular skeleton (all synovial joints) |
3 structural classifications of joints | Fibrous
Cartilaginous
Synovial |
Immovable or slightly movable joints that do not have a joint cavity | Fibrous Joints |
3 types of fibrous joints | Sutures
Syndesmoses
Gomphoses |
Joints that only occur in the bones of the skull and allow bone growth so the skull can expand with the brain during childhood | Sutures |
closed sutures (fibrous tissue ossifies in middle age) | Synostoses |
Interosseous membrane between radius and ulna is a freely movable diarthrosis | Interosseous membrane between radius and ulna is a freely movable diarthrosis |
Tooth in a socket
Connecting ligament—the periodontal ligament | Gomphoses |
Joints that lack a joint cavity | Cartilaginous joints |
2 types of cartilaginous joints | Synchondroses and Symphyses |
Is the joint between the first rib and sternum movable or immovable? | immovable |
Slightly movable joints that provide strength with flexibility | Slightly movable joints that provide strength with flexibility |
unites bones; resists tension and compression | Fibrocartilage |
Most movable type of joint
All are diarthroses
Each contains a fluid-filled joint cavity | Synovial Joints |
Absorbs compression | Articular cartilage |
Unique to synovial joints
Space that holds a small amount of synovial fluid | Joint cavity (synovial cavity) |
joint cavity is enclosed in a two-layered capsule called | Articular capsule |
dense irregular connective tissue, which strengthens joint | Fibrous capsule |
Loose connective tissue
Lines joint capsule and covers internal joint surfaces
Functions to make synovial fluid | Synovial membrane |
A viscous fluid similar to raw egg white
A filtrate of blood
Arises from capillaries in synovial membrane
Contains glycoprotein molecules secreted by fibroblasts | Synovial fluid |
Often are thickened parts of the fibrous capsule
Sometimes are extracapsular ligaments—located outside the capsule
Sometimes are intracapsular ligaments—located internal to the capsule | Reinforcing ligaments |
Look at slide 21 in PP CHAP-9 to see the Structure of a Synovial Joint | Look at slide 21 in PP CHAP-9 to see the Structure of a Synovial Joint |
Richly supplied with sensory nerves
Detect pain
Most monitor how much the capsule is being stretched
Branches of several major nerves and blood vessels
Have a rich blood supply
Serve as lubricating devices | Synovial Joints
(function: Fluid is squeezed out as opposing cartilages touch
and allows cartilage to ride on the slippery film) |
Are bursae and tendon sheaths synovial joints? | No, they are closed bags of lubricant that reduce friction between body elements |
a flattened fibrous sac lined by a synovial membrane | Bursa |
an elongated bursa that wraps around a tendon | Tendon sheath |
3 basic types of movement | 1) Gliding—one bone across the surface of another
2) Angular movement—movements change the angle between bones
3) Rotation—movement around a bone's long axis |
Gliding occurs between: | Carpals
Articular processes of vertebrae
Tarsals
(Movements include:
Flexion and extension
Abduction and adduction
Circumduction) |
Abduction | Away from the body
("b for bye") |
Adduction | Towards the body |
What is the only movement allowed between the atlas and axis vertebrae? | Rotation |
Rotation away from the center of the body | Lateral rotation |
Rotation toward the center of the body | Medial rotation |
Moving a body part downward | Depression (opening your mouth/moving your chin downwards) |
Moving a body part upward | Elevation (closing your mouth/moving your chip upward) |
Movement anteriorly | Protraction |
Movement posteriorly | Retraction |
Forearm rotation laterally with palms facing anteriorly | Supination
(sup?) |
Forearm rotation medially with palms facing posteriorly | Pronation (brings radius across the ulna) |
Moving thumb to touch the tips of other fingers | Opposition |
Turning your foot medially | Inversion
(inward) |
Turning your foot laterally | Eversion |
Lifting the foot towards the shin | Dorsiflexion |
Depressing the foot; elevating the heel | Plantarflexion |
Shape classifications of Synovial Joints | Plane Joint
Hinge Joint
Pivot Joint
Condyloid Joint
Saddle Joint
Ball-and-socket Joint |
Plane joint | Articular surfaces are flat planes
Short gliding movements are allowed
Intertarsal and inter-carpal joints
Movements are non-axial
Gliding does not involve rotation around any axis |
Hinge joints | Cylindrical end of one bone fits into a trough on another bone
Angular movement is allowed in one plane
Elbow, ankle, and joints between phalanges
Movement is uniaxial—allows movement around one axis only |
Pivot Joint | Classified as uniaxial – rotating bone only turns around its long axis
Examples
Proximal radioulnar joint
Joint between atlas and axis |
Condyloid Joint | Allow moving bone to travel
Side to side—abduction-adduction
Back and forth—flexion-extension
Classified as biaxial—movement occurs around two axes |
Saddle Joint | Each articular surface has concave and convex surfaces
Classified as biaxial joints
1st carpometacarpal joint is a good example
Allows opposition of the thumb |
Ball-and-socket Joint | Spherical head of one bone fits into round socket of another
Classified as multiaxial—allow movement in all axes
Shoulder and hip joints are examples |
prevent excessive motions
On the medial or inferior side of a joint – prevent excessive abduction
Lateral or superiorly located—resist adduction | Ligaments |
resist extension and lateral rotation | Anterior ligaments |
resist flexion and medial rotation | Posterior ligaments |
Helps stabilize joints by keeping tension on tendons
Is important in reinforcing:
Shoulder and knee joints
Supporting joints in arches of the foot | Muscle tone |
Is a saddle joint
Four ligaments surround the joint
Anterior and posterior sternoclavicular ligaments
Interclavicular ligament
Costoclavicular ligament
Performs multiple complex movements | Sternoclavicular joint |
Is a modified hinge joint
The head of the mandible articulates with the temporal bone
Lateral excursion is a side-to-side movement of the mandible | Temporomandibular Joint |
The most freely movable joint, lacks stability
Articular capsule is thin and loose
Muscle tendons contribute to joint stability | Shoulder (glenohumeral) joint |
4 muscles of the rotator cuff | 1) Subscapularis
2) Supraspinatus
3) Infraspinatus
4) Teres minor |
Allows flexion and extension
The humerus’ articulation with the trochlear notch of the ulna forms the hinge
Tendons of biceps and triceps brachii provide stability | Elbow joint |
Stabilized by numerous ligaments
Composed of radiocarpal and intercarpal joint | Wrist |
joint between the radius and proximal carpals (the scaphoid and lunate)
Allows for flexion, extension, adduction, abduction, and circumduction | Radiocarpal joint |
joint between the proximal and distal rows or carpals
Allows for gliding movement | Intercarpal joint |
A ball-and-socket structure
Movements occur in all axes
Limited by ligaments and acetabulum
Head of femur articulates with acetabulum
Stability comes chiefly from acetabulum and capsular ligaments
Muscle tendons contribute somewhat to stability | Hip joint |
The largest and most complex joint
Primarily acts as a hinge joint
Has some capacity for rotation when leg is flexed
Structurally considered compound and bicondyloid
Two fibrocartilage menisci occur within the joint cavity | Knee joint |
shares the joint cavity
Allows patella to glide across the distal femur | Femoropatellar joint |
Covers posterior and lateral aspects of the knee
Covers tibial and femoral condyles
Does not cover the anterior aspect of the knee
Anteriorly covered by three ligaments
Patellar ligament,
Medial, and lateral patellar retinacula | Capsule of the knee joint |
Become taut when knee is extended | Ligaments of the knee joint |
extracapsular and capsular ligaments of the knee: | A) Fibular and tibial collateral ligament,
B) Oblique popliteal ligament, and
C) Arcuate popliteal ligament |
Ligaments that cross each other like an “X” | Cruciate ligaments
(Each cruciate ligament runs from the proximal tibia to the distal femur and prevent undesirable movements at the knee) |
prevents anterior sliding of the tibia | Anterior cruciate ligament |
prevents forward sliding of the femur or backward displacement of the tibia | Posterior cruciate ligament |
"The Unhappy Triad" | Lateral blows to the knee |
A hinge joint between
United inferior ends of tibia and fibula
The talus of the foot
Allows dorsiflexion and plantar flexion movements only | Ankle Joint
(medially and laterally stabilized by ligaments) |
Disorders of Joints | Structure of joints makes them prone to traumatic stress
Function of joints makes them subject to friction and wear
Affected by inflammatory and degenerative processes |
Injuries of Joints | Torn cartilage— common injury to meniscus of knee joint
Sprains— ligaments of a reinforcing joint are stretched or torn
Dislocation— occurs when the bones of a joint are forced out of alignment |
inflammation of a bursa due to injury or friction | Bursitis |
inflammation of a tendon sheath | Tendonitis |
describes over 100 kinds of joint-damaging diseases | Arthritis |
most common type of “wear and tear” arthritis | Osteoarthritis |
Synovial joints develop from: | |
Joints resemble adult joints by which week of development? | Week 8
(Outer region of mesenchyme becomes fibrous joint capsule
Inner region becomes the joint cavity) |