Joint Structure and Function Flashcards
Describe what is meant by ‘structural classification of joints’
Based on the presence or absence of a synovial joint cavity and the type of connecting tissue that is present e.g. fibrous, cartilaginous or synovial
Define ‘synarthroses’
Immovable joint
Define ‘amphiarthroses’
Partially movable joint
Define ‘diarthroses’
Freely movable joint
What are ‘fibrous joints’?
No synovial cavity, articulating bones held by fibrous connective tissue (little movement)
Give 3 examples of fibrous joints.
Teeth, interosseous membrane between radius and ulna (and tibia and fibula), and skull sutures
Define ‘synostosis’
Ossified immovable structure (i.e. sutures of skull)
Define ‘syndesmosis’
Sheet of fibrous tissue between bones (i.e. interosseous membrane)
Define ‘gomphosis’
Cone shaped peg that fits into socket (i.e. teeth)
What are ‘cartilaginous joints’?
No synovial cavity, articulating bones connected by fibrocartilage or hyaline cartilage (little movement)
Give 3 examples of cartilaginous joints.
Pubic symphysis, intervertebral discs and epiphyseal growth plate
Define ‘synchrondosis’
Two bones connected by hyaline cartilage (e.g. epiphyseal growth plate)
Define ‘symphysis’
Two bones connected by disc of fibrocartilage (e.g. intervertebral discs and pubic symphysis)
What are ‘synovial joints’?
A synovial joint cavity exists between articulating bones (freely movable)
What is an ‘arthrogram’?
Iodine injected into joint cavity and illustrates the cavity and interconnected bursae so it can be seen on x-ray
Describe the articulating cartilage at synovial joints.
Hyaline cartilage covers the bone ends and is an elastic, resilient structure which acts as a shock absorber to protect the underlying bone
Why is hyaline cartilage a good cover for articulating bone surfaces?
Has smooth, slippery and low friction surface and a level of elasticity and shock absorption.
Describe the structure of the articulating capsule in synovial joints.
Articulating capsule surrounds joint and encloses synovial cavity (uniting two bones). There is the outer fibrous capsule (may contain ligaments) and the inner synovial membrane (secretes synovial fluid - nourishing and lubricating)
What is meant by osteoarthritis?
The degeneration of the articulating cartilage (hyaline or fibrocartilage depending on joint)
Name the 6 types of synovial joint
Hinge, pivot, plantar, ellipsoidal (condylar), ball and socket and saddle
Describe a plantar joint - including the movements possible.
Can move side to side, back and forth to facilitate sliding movements.
Give examples of plantar joints.
Intercarpals and intertarsals
Describe a hinge joint - including the movements possible.
The convex surface of one bone fits into concave of other to facilitate flexion and extension (single plane).
Give examples of hinge joints.
Elbow and knee
Describe a pivot joint - including the movements possible.
Round/pointed surface of one bone fits into ring formed by another (in addition to presence of ligament) and the movement facilitated is rotational.
Give examples of pivot joints.
Atlas rotating on the axis (in the neck, C1 and C2) OR the radius and the annular ligament of the ulna (radius moves over ulna in supination and pronation movements)
Describe a condylar (ellipsoidal) joint - including the movements possible.
Oval shaped condyle of one bone fits into elliptical cavity of the other bone and all movements are possible at this joint
Give examples of condylar joints
Joint between carpals and radius (articulation between the scaphoid and the radius and the lunate and the radius)
Describe a saddle joint - including the movements possible
One bone is ‘saddle-shaped’ and other is ‘rider’ all movements possible at these joints
Give an examples of a saddle joint
Carpometacarpal joint of thumb (CMC)
Describe a ball-and-socket joint - including the movements possible
Ball-shaped surface of one bone fits into cup-like depression of other, all movements possible at these joints
Give examples of ball-and-socket joints
Hip and shoulder joints
Rank the 6 synovial joint types from the least to most movable
plantar, hinge, pivot, condylar, saddle, ball-and-socket
