Joints Flashcards
Joint
Is a site of articulation. Functions are to give skeleton mobility and hold skeleton together
Articulation
Site where two or more bones meet
Structural Classification of Joint
Based on binding material
Functional Classification of Joint
Based on amount of movement
Synarthroses
immovable joints
Amphiarthroses
Slightly moveable
Diarthroses
Freely moveable joints
Fibrous Joints
Bones joined by dense fibrous connective tissue, no joint cavity, most immovable. Three major types of fibrous joints
Sutures
Rigid, interlocking joints. Allow for growth during youth. In middle age, sutures ossify and fuse (synostoses) Immovable joints for protection of brain
Syndesmoses
Bones connected by ligaments, cords or bands of fibrous tissue. fiber length varies, so movement varies
Gomphoses
Rare type of fibrous joint. Peg-in-socket joints only example is teeth in alveolar
Cartilaginous Joints
Bones united by cartilage, no joint cavity and not highly movable. Two type are synchonroses and symphases
Synchondroses
Bar/plate of hyaline cartilage unites bones, are immovable.
Symphyses
Fibrocartilage unites bone, hyaline cartilage is also present as articular cartilage on the bony surface. Strong, flexible amphiarthroses (slightly moveable). Shock Absorber.
Synovial Joints
Articulating bones separated by fluid-filled joint cavity. All are diarthrotic. Nearly all limb joints and most joints of body fall into this category.
Six Distinguishing features of synovial Joints
- Articular cartilage
- Joint (synovial) Cavity (small, fluid-filled space)
- Articular capsule (two layers; external fibrous layer and inner synovial membrane)
- Synovial Fluid
- Reinforcing Ligaments (capsular, extracapsular or intracapsular)
- Nerves and Blood Vessels (detect pain, monitor joint position and stretch)
Bursae
Sacs lined with synoival membrane (contains synovial fluid). Reduce friction where ligaments, muscles, skin, tendons, or bones rub together. (picture a yoga ball)
Tendon Sheaths
similar to bursae, but it wraps around the tendon subjected to friction. elongated bursae.
Nonaxial
Slipping movements only
Uniaxail
movement in mone plane
Biaxial
Movement in two planes
Movements at synovial Joints
Gliding, angular movements, rotation and special
Gliding Movements
one flat bone surface glides or slips over another similar surface. ex. waving. Non-axial movement, gliding.
Angular movements
Increases or decreases angle between two bones. ex. Flexion, extension, hyperextension, abduction, adduction, cirucumduction. nodding would be an example of the first three.
Rotation Movement
turning of bone around its own long axis. Medial rotation (toward midline), lateral rotation (away from midline). Example would be rotation of humerus and femur.
Special Movements
Most are movements of a specific joints, supination (turning hand out) and pronation (turning hand in). Dorsiflexion (pull toes up), plantar flexion (pointing toes). Inversion (foot turning inward) eversion (foot turing outward)
plane joints
nonaxial (bones in hand)
HInge joints
Uniaxial (elbow)
Pivot joints
Uniaxial (atlas-axis)
Condyloid joints
Biaxial (wrist)
Knee Joint
Most complex joint in the body. Three joints surrounded by a single joint cavity. Contains 6 stabilizing ligaments and at least 12 associated bursae.
Knee joint injuries
vulnerable to horizontal blows, especially laterally blows to extended knee. Three C’s (collateral ligaments, cruiciate ligaments (torn ACL), cartilages) Happens in sports injuries.
Elbow Joint
Articulation of the radius and Ulna with the humerus. It’s a hinge Joint. Flexion and extension only. Anular Ligament allows for supination and pronation. Ulnar and Radial collateral ligaments- restrict side-to-side movement.
Shoulder Joint
Ball and Socket Joint. Head of humerus with glenoid cavity of scapula. Most freely moving joint in the body. Because of this stability is sacrificed. Reinforcing Ligaments -> Coracohumeral ligament and three glenohumeral ligaments. Reinforcing Tendons ->Four rotator cuff tendons encircle the shoulder joint.
Hip (coxal) Joint
Ball-and-socket Joint. Head of the femur articulates with the acetabulum. Good range of motion, but limited by the deep socket. 4 Reinforcing Ligaments-> Ilofemoral ligament, pubofemoral ligament, Ischiofemoral ligament, Ligamentum Teres.
Temporomandibular Joint (TMJ)
Mandibular condyle articulates with temporal bone. Two types of movement (hing and gliding). Most easily dislocated joint in the body.
Common Joint Injuries
cartilage tears, sprains and dislocations (luxations)
Bending your head back until it hurts is an example of _______
hyperextension
Fibrous joints are classifed as ________
sutures, Syndesmoses, Gomphoses
This type of synovial joint is used when you bend your fingers to hang onto a cliff
hinge
The two main types of joint classification are
structure and function
a unique feature of synovial joints is
a joint cavity
what movement has occurred when you bend your fingers to make a fist?
flexion
what is moving a limb away from the median plane of the body along hte frontal plane called?
abduction
the site where 2 or more bones meets is called an
articulation site
what are the three structural types of joints?
fibrous, cartilaginous, gomphoses
the viscous egg white consistency of synovial fluid is due to
hyaluronic acid
