Chapter 8 Articulations

Describe the functional classification of joints based on degree of movement

allowed: synarthrosis, amphiarthrosis, and diarthrosis.

synarttrosis -does not allow any movement

amphiarthrosis- allows a small amount of movement

diarthrosis- freely moveable

Describe the structural classification of joints based on their anatomical features.

fibrous joints- fastened together by dense regular collagenous connective tissue

cartilaginous joints- fastened together with cartilage

synovial- layer of hyaline cartilage, fluid filled cavity

Discuss the common features of fibrous joints. Describe the three subclasses of

fibrous joints and provide examples of where each are located.

fibrous joints are connected by dense connective tissue, contains no joint cavity, little or no movement

suture- immoveable joint- protecting brain

gomphosis- immoveable joint between each tooth and its bony socket in jaw

syndesmosis- joints between tibia, fibula, ulna, and radius.bones are joined by an interosseous membrane.small movement

Discuss the common features of cartilaginous joints. Described the two

subclasses of cartilaginous joints and provide examples of where each are

located.

cartilaginous joints-connected by cartilage. lack joint. little or no movement

subclasses; synchondroses-linked together by hyaline cartilage. ex-epithelial plates

symphysis- bones are united by fibrocartilaginous. ex- intervertebral joints, pubic symphysis

Identify the structural components of a synovial joint, including accessory structures such as ligaments, tendons, bursae, and tendon sheaths.

synovial joint- space found between articulating bones

articular cartilage- thin layer of hyaline cartilage that covers all exposed articulating bones with a joint.provide a smooth surface. avascular

synovial fluid- lubricates the joint and reduces friction.serves as a metabolic friction.provides for shock absorption

ligaments- bone to bone

tendons-muscle to bone

bursae-synovial fluid fibrous helps to minimize friction

tendon sheaths-long bursa thatt surrounds tendons and protects tendons as they slide across joint

Describe the four functional classes of synovial joints based on the axes of

rotation.

nonaxial- allow motion to occur in one or more planes without moving

uniaxial- allows movement around one axis

biaxial-allow motion. between two axes

multiaxial- allow motion around three axisl

Describe the movements of synovial joints. Demonstrate examples of each type

of movement.

glinding- gilding is a sliding motion. nonaxial

angular- increase or decrease angle between articulating bones

flexion- decreases angle between articulating bones by bringing bones closer to one another

hyperextension- extension beyond anatomical position of joint

abduction- movement away from the body’s midline

adduction- movement towards the body’s midline

circumduction- only unpaired angular movement where a freely moveable distal bone moves on a fixed proximal

rotation- nonangular motion one bone rotates on imaginary line running down its middle longitudinal axis

depression- movement of body part inferior (downward)

elevation-moves a body in a superior direction (upward)

protraction- moves body anterior (forward)

retraction- moves body posterior (forward)

inversion- foot rotates medially (inward)

eversion- rotates foot laterally (outward)

dorsiflexion- foot and leg decreases (walking heel to toe)

plantarflexion- foot and leg increases (on your tip toes)

supination- rotational movements of wrist and ankles

pronation- rotational movements of wrist and ankles

Describe the six types of synovial joints and provide examples of each

plane joint-gliding ex.carpal bones

hinge joint-ex.elbow and knee

pivot joint-ex.atlantoaxial joint

condylar joint-ex. metacarpophalangeal joint

saddle joint-ex. trapezium and first metacarpal

ball-and-socket joint- ex. shoulder and hip