Lecture 5 Flashcards
Types of joints by function (3)
- Synarthroses
- Amphiarthroses
- Diarthroses
Synarthroses joints
Immovable joints
Amphiarthroses joints
Slightly movable joints
Diarthroses joints
Freely movable joints
Types of join by structure (3)
- Fibrous joints
- Cartilaginous
- Synovial
Fibrous joints
Suture or syndesmosis
Suture joints
Joint is held together with short, interconnecting fibers
Bone edges interlock
Only on skull
Syndemosis joints
Bones are held together by a ligament
Fibrous tissue can vary in length
Between radius and ulna: large amounts of movement possible
Distal tibiofibular joint
Between fibula and tibia
Syndemosis joint
Cartilaginous joints
Synchondroses or symphyses
Synchondroses joints
Bones united by hyaline cartilage
Immobile
Ie. epiphyseal plates, 1st rib’s cartilage, manubrium of sternum
Symphyses joints
Fibrocartilage connects two bones
Slight movement
Ie. symphysis pubis, symphysis menti, intervertebral discs
Synovial joints (6)
Most movable joints in the body All have hyaline at ends of articulating bones Joint cavities Articular capsule Synovial fluid All are diarthroses Intra and extracapsular ligaments to enforce the joints Most joints in body are synovial 1. Plane 2. Hinge 3. Pivot 4. Condylar 5. Saddle 6. Ball and socket
Plane synovial joints
Between two flat surfaces
Allow for limited gliding movements between bones
Ie. between tarsal bones of the foot
Hinge synovial joints
Cylinder and trough
Ie. elbow, knee, ankle
Pivot synovial joints
Rotate around axis
Ie. between first and second cervical vertebrae, radius and ulna
Condylar synovial joints
One round bone and one concave
Ie. radiocarpal joint of wrist, metacarpal phalangeal joint
Saddle synovial joints
Saddle and rider
Ie. 1st carpometacarpal joint (base of thumb)
Ball and socket synovial joints
Hip and shoulder joints ONLY
Articular cartilage
Synovial joints
At ends of articulating bones
Hyaline
Joint cavity
Space that holds synovial fluid
Articular capsule
Encloses joint cavity
Fibrous membranous capsule
Synovial fluid
Viscous fluid inside the joint cavity
Flexion
Decreases angle between the bones Arm: all the way forward Forearm: all the way up from elbow forward Fingers: folded down at joints Wrist: forward Thumb: flat against palm Thigh: all the way forward Leg: bent backwards and knee
Extension
Increases angle between the bones Arm: all the way back Forearm: elbox straight Fingers: flat hand Wrist: backwards Thumb: outwards, in plane with hand Thigh: all the way back Leg: straight leg
Abduction
Moving a limb away from the body
Arm: Parallel to ground, outward
Wrist: hand moves inward in pinky direction
Fingers: fingers apart
Thumb: thumb inline with fingers
Thigh: lifts leg outwards (widening legs)
Adduction
Moving a limb towards the body Arm: flat against body, down Wrist: hand moves outward in thumb direction Fingers: fingers together Thigh: legs close together
Circumduction
Flexion, extension, abduction and adduction together to give circular motion
Rotation
Movement of bone around longitudinal axis
Gliding
Sliding the flat surfaces of two bones across each other
Flexed knee
Can also rotate medially and laterally
Unflexed: locked
Joint is most complex in body
Opposition of thumb
Thumb towards fingers: as to pick them up
Dorsiflexion
Ankle upward
Foot pointing upwards
Plantarflexion
Ankle downward
Foot pointing downward
