Lab 10: Joints Flashcards
joints, or articulations
-what are they
How bones attached to one another. Only place movement can occur
Classification of Joints - 2 types (with 3 subtypes each)
Functional: -based on movement at joint • synarthroses (immovable) joints • amphiarthroses (slightly movable) joints • diarthroses (freely movable) joints
Structural: -type of connective tissue + if has joint cavity • fibrous joints • cartilaginous joints • synovial joints.
Fibrous Joints
- dense fibrous connective tissue
- very strong
- little or no movement.
- no joint cavity
- 2 Types: Sutures + Syndesmoses
Sutures
– dense connective tissue
– synarthroses (immovable)
– Ex. joint between cranial and facial bones
Syndesmoses
– dense connective tissue
– movement depends on length of connecting fibers
– example: distal articulation between tibia and fibula (immovable, best described as “give”)
Cartilaginous Joints
- cartilage
- no joint cavity
- permit little or no movement
- 2 types: Synchondroses + Symphyses
Synchondroses
– hyaline cartilage
– synarthroses (immovable) joints
– examples: costal cartilages of rib #1 and manubrium
Symphyses
– fibrocartilage
– amphiarthroses (slightly movable) joints
– examples: intervertebral discs; pubic symphysis
Synovial Joints
- Most joints in the body
- movement limited only by ligaments, muscles, tendons, or adjoining bones
- diarthroses (freely movable) joints
- joint cavity
- synovial fluid: lubricates joint, provides nourishment for the articular cartilage.
Synovial joints - 6 categories
1) Plane (Gliding) Joints
2) Hinge Joints
3) Pivot Joints
4) Condyloid (Ellipsoid) Joints
5) Saddle Joints
6) Ball-and-Socket Joints
Plane (Gliding) Joints
- articulating = flat
- nonaxial
- slight movement
- Ex. carpal-carpal, tarsal-tarsal
Hinge Joints
- Convex –> concave
- monaxial
- flexion and extension
- Ex. : elbow/ankle/knee joint
Pivot Joints
- Rounded surface –> ring-like surface
- monaxial
- rotation
- Ex. atlas –> axis
Condyloid (Ellipsoid) Joints
- Oval Convex –>Oval concave
- biaxial
- flexion and extension, abduction and adduction, circumduction and rotation
- Ex. radius –> carpal bones
Saddle Joints
- Each has both convex and concave areas
- biaxial
- flexion and extension, abduction and adduction, circumduction
- Ex. Thumb joint (carpal –> metacarpal bone)
Ball-and-Socket Joints
- Ball like –> cup like
- biaxial
- flexion and extension, abduction and adduction, circumduction and rotation
- Ex. shoulder joint; hip joint
Abduction
ABDuction
movement of limb away from the medial line
Adduction
ADDuction
movement of limb toward medial line
Flexion
2 special
decreases the angle between articulating bones
ankle joint Flexion:
- Dorsiflexion - toes point upward (stand on heels)
- Plantar flexion - toes point downward (tiptoe)
Extension
increases the angle between articulating bones
Hyperextension
the continuation of extension beyond anatomical position.
Rotation
the movement of a bone around its own longitudinal axis without lateral displacement of the body part.
Circumduction
movement in which one end of a limb remains relatively stationary while the distal end of the limb moves in a circle.
Pronation
movement of the hand from a palm-up to a palm-down (prone) position.
Supination
2 special
movement of the hand from palm-down to palm-up (supine) position.
Supination of foot:
- Eversion - soles turn outward (laterally)
- Inversion - soles turn inward (medially)
bursae
flattened fibrous sacs, contain synovial fluid to help decrease friction on the shoulder where tendons and muscles cross the joint capsule.
