Joints Flashcards
What are joints? Alternative names?
A joint is a point of contact between:
Two or more bones
Cartilage and bone
Teeth and bone
Also called articulation or arthrosis
Ways to classify a joint?
Structurally
Is there a joint cavity?
What type of connective tissue is involved?
Functionally
What degree of movement?
3 types of joints (structural classification)
Fibrous – no articular cavity / little or no movement
Articulating bones held together by dense irregular connective tissue
Types: Sutures and Syndesmoses (immoveable… like sutures in skull or sydesmoses ligament between tibia and fibula)
Cartilaginous – no articular cavity / slightly moveable
Articulating bones held together by hyaline cartilage (Synchondrosis - an almost immoveable joint like vertebra, or cartilaginous joints between manubrium and ribs) or fibrous cartilage (Symphysis - slightly moveable)
Synovial – with articular cavity
Characterized by synovial cavity and articular cartilage; may contain accessory ligaments, articular discs and bursae
Synovial Joints
Have a synovial cavity
Articulating bones are covered with articular cartilage, held together by ligaments, contain synovial fluid, have a nerve and blood supply, and are surrounded by an articular capsule
Permit a large range of movement
Bursae
sac-like structures filled with synovial fluid that cushion movement of one body part over another
Tendon Sheaths
a tube-like bursae that wraps around tendons subject to a great deal of friction
Adduction / Abduction
Abduction moves the limb laterally away from the midline of the body
Adduction is the opposing movement that brings the limb toward the body or across the midline
Flexion / Extension
Flexion describes a bending movement that decreases the angle between a segment and its proximal segment.
Extension is the opposite of flexion, describing a straightening movement that increases the angle between body parts. For example, when standing up, the knees are extended.
Circumduction
Circumduction is a conical movement of a body part, such as a ball and socket joint or the eye. Circumduction is a combination of flexion, extension, adduction and abduction. … For example, circumduction occurs when spinning the arm when performing a serve in tennis or bowling a cricket ball. (Spiral motion)
Lateral / Medial rotation
Medial and lateral rotation describe movement of the limbs around their long axis:
Medial rotation is a rotational movement towards the midline. It is sometimes referred to as internal rotation. Imagine a straight leg, rotate it to point the toes inward. This is medial rotation of the hip.
Lateral rotation is a rotating movement away from the midline. This is in the opposite direction to the movements described above.
Elevation / Depression / Protraction / Retraction
Elevation
Superior movement of body part. (mandible)
Depression
Inferior movement of body part. (mandible)
Protraction
Anterior movement of body part in transverse plane. (push head forward)
Retraction
Posterior movement of body part in transverse plane. (pull head inwards / chin in)
Inversion / Eversion / Dorsiflexion / Plantar Flexion
Inversion
Medial movement of sole. (rotate foot inwards)
Eversion
Lateral movement of sole. (rotate foot out)
Dorsiflexion
Bending foot in direction of dorsum (superior surface). (pull foot up)
Plantar flexion
Bending foot in direction of plantar surface (sole). (push foot down)
Factors affecting contact and range of motion at synovial joints
> Structure and shape of the articulating bones
Strength and tension of the joint ligaments
Arrangement and tension of the muscles
Contact of soft parts
Hormones
Disuse
Suture
Between skull bones.
Fibrous joint.
No movement.
Altanto-occipital
Between superior articular facets of atlas and occipital condyles of occipital bone.
(top of spine and skull)
ellipsoid
Altanto-Axial
Synovial pivot for rotation of the head
c1 / c2
Intervertebral
(1) Between vertebral bodies
(2) Between vertebral arches
Cartilaginous (symphysis) between vertebral bodies; Synovial (planar) between vertebral arches.
Allow:
Flexion, extension, lateral flexion, and rotation of vertebral column.
Vertebrocostal
(1) Between articular facets of heads of ribs and costal facets of bodies of adjacent thoracic vertebrae and intervertebral discs between them;
(2) Between articular facet of tubercles of ribs and transverse costal facet of thoracic
Synovial (planar).
Slight gliding.
Sternocostal
Between sternum and first seven pairs of ribs.
Cartilaginous (synchondrosis) between sternum and first pair of ribs;
synovial (plane) between sternum and second through seventh pairs of ribs.
No movement between sternum and first pair of ribs; slight gliding between sternum and second through seventh pairs of ribs.
Lumbosacral
(1) Between body of fifth lumbar vertebra and base of sacrum;
(2) Between inferior articular facets of fifth lumbar vertebra and superior articular facets of first vertebra of sacrum.
Cartilaginous (symphysis) between body and base; synovial (planar) between articular facets.
Flexion, extension, lateral flexion, and rotation of vertebral column.
Sternoclavicular
Sternoclavicular
Between sternal end of clavicle, manubrium of sternum, and first costal cartilage.
Synovial (plane, pivot).
Gliding, with limited movements in nearly every direction.
Acromiociavicular
Between acromion of scapula and acromial end of clavicle.
Synovial (plane).
Gliding and rotation of scapula on clavicle.
Radioulnar
Radioulnar
Proximal radioulnar joint between head of radius and radial notch of ulna; distal radioulnar joint between ulnar notch of radius and head of ulna.
Synovial (pivot).
Rotates forearm
Wrist (radiocarpal)
Between distal end of radius and scaphoid, lunate, and triquetrum of carpus.
Synovial (ellipsoid).
Flexion, extension, abduction, adduction, circumduction, and slight hyperextension of wrist.
