A&P 1 chapter 9
Articulation
any place where adjacent bones or bone & cartilage come together (articulate with each other) to form a connection; A JOINT
2 main factors affect the type of joint & degree of movement at a joint:
3 Structural types of joints
Structural classification of joints
based on whether the articulating surfaces of the adjacent bones are directly connected by fibrous connective tissue or cartilage, or whether the articulating surfaces contact each other within a fluid-filled joint cavity
Suture joint
between skull bones
Syndesmosis
bones are more widely separated; held together by ligament or interosseous membrane (ex. between radius & ulna)
Gomphosis
joint of a tooth within its socket
Fibrous Joints
adjacent bones are directly connected by fibrous connective tissue; they have no joint cavity
ex. suture joint, syndesmosis & gomphosis
Cartilaginous joints
the bones are joined by hyaline cartilage or fibrocartilage
ex. synchondrosis & symphysis
Synchondrosis
bones are joined together by hyaline cartilage; 2 types:
Symphysis
bones are joined by fibrocartilage; pubic symphysis or intervertebral disks
Synovial joints
the articulating surfaces of the bones are not directly connected but instead come into contact with each other within a joint cavity the is filled with a lubricating fluid.
Functional classification of joints
determined by the amount of mobility found between the adjacent bones
3 functional types
Synarthrosis Joints
immobile joint
Amphiarthrosis Joints
slightly mobile joint
Diarthrosis
freely moveable joint
Synostosis (Synostoses plural)
the fusion of 2 bones & the most common example is in the long bone when the Epiphysis (rounded bone end) fuses with the Diaphysis (shaft) upon closure of the epiphyseal plate after puberty (forming the epiphyseal line) between the bone
Articular capsule
a fibrous connective tissue structure that is attached to each bone just outside the area of the bones articulating surface forming the walls of the joint cavity
Articular cartilage
a thin layer of hyaline cartilage that covers the entire articulating surface of each bone end (prevents friction between the bones)
Synovial membrane
a thin connective tissue membrane that lines the inner surface of the articular capsule whose cells secrete a lubricating fluid (synovial fluid)
Synovial fluid
a thick, slimy fluid that provides lubrication to further reduce friction between the bones of the joint
Ligament
connects bone to bone
Tendon
connects muscle to bone
Articular disc
a fibrocartilage structure located between the articulating bones that is small and oval shaped which acts to strongly unite the bones of the joint
Meniscus
a fibrocartilage structure located between the articulating bones that is large and C-shaped which provides shock absorption and cushioning between the bones
Bursa
sac of thin connective tissue that is filled with lubricating fluid
Tendon Sheath
similar in function to a bursa; it is a connective tissue sac (fluid filled) that surrounds a muscle tendon at places where the tendon crosses a joint
Pivot Joint
uniaxial: rotation around a single axis
Hinge Joint
uniaxial: bending or straightening in a single axis
Condyloid Joint
biaxial: allows movement in 2 planes
Saddle Joint
biaxial joint
Plane Joint
"multiaxial"
Ball-and-socket Joint
multiaxial
Flexion
decrease joint angle
Extension
increase joint angle
Abduction
movement away from midline
Adduction
movement towards midline
Circumduction
the movement of a body region in a circular manner in which one end moves to "describe" a circle and the other stays relatively stationary (arm or leg "circles")
Rotation
circular or twisting movement about the long axis of a bone or column of bones
Dorsiflexion
lifting the toes up or "walking on heels"; action that lifts the front of the foot which results in the top of the foot moving towards the anterior leg
Plantar flexion
pointing the toes downward
Supination
movement of the forearm (rotation of the radius) that results in the radius and the ulna becoming parallel to one another and the palm facing forward (in anatomical position)
Pronation
is in opposite direction to the supination and results in the radius crossing over the ulna in an "X-shape" position and the palm facing backward (out of anatomical position)
Inversion
turning the plantar surface of the foot toward the midline
Eversion
turning the plantar surface of the foot outward or away from the midline
Opposition
is the thumb movement that brings the tip of the thumb in contact with the tip of a finger
Bursitis
the inflammation of a bursa near a joint
causes pain, swelling or tenderness of the surrounding area; may be acute or chronic
Osteoarthritis
a common disorder of synovial joints that involves inflammation of the joint associated with aging and "wear and tear" of the articular cartilage
Gout
a form of arthritis, or inflammation of the synovial joint, that results from the deposition of uric acid crystals within the body joint; body is producing too much uric acid
Rheumatoid Arthritis
(RA) an inflammation joint disease of autoimmune etiology wherein the immune system of the body attacks its own joints
Sprain
the stretching or tearing of ligaments surrounding a joint
Strain
the stretching or tearing of tendon fibers
RICE
(Rest, Ice, Compression, Elevation) common treatment technique
Temporomandibular Joint
Shoulder Joint
Hip Joint
Knee Joint