Joints TEST Flashcards
What is a joint?
A joint is a functional junction between bones
What is arthrology?
Arthrology is the study of joints
What are the three major types of joints (classified by the type of tissue binding the joint)?
- Fibrous (fibrous connective tissues)
- Cartilaginous (fibrocartilage connective tissue)
- Synovial (synovial membrane, and epithelial tissue)
Describe the characteristics of fibrous joints and give an example of this type of joint
Fibrous joints are immovable. They have a tiny bit of fibrous connective tissue between the bones they join. Examples of fibrous joints are the sutures of cranial bones.
Describe the characteristics of cartilaginous joints and give an example of this type of joint
Cartilaginous joints have tough fibrocartilage connective tissue between the bones they join. They are able to move slightly. Examples of cartilaginous joints include the (1) intervertebral disc and (2) pubic symphysis
Describe the characteristics of synovial joints and give an example of this type of joint.
Synovial joints are the most common type of joint in the body and have synovial membranes (an epithelial tissue) lining the joint and secreting synovial fluid. Synovial joints allow free movement. Examples of synovial are the (1) humerus articulating with the glenoid cavity of the scapula, an d(2) the femur articulating with the acetabulum of the hipbone or coxa.
What is the basic structure of a typical synovial joint?
- Have articular cartilage (hyaline cartilage) at the ends of the two articulating bones
- Have synovial membranes that surround the joint and produce synovial fluid which fills the synovial cavity
- Have a joint capsule made of heavy connective tissue which surrounds the entire joint to protect and stabilize it
- Have bursae (outpockets of membranes) to help cushion the joint
What are the functions of the synovial joint structures?
- Articular cartilage is very smooth and reduces friction between the two articulating bones
- Synovial membranes secrete synovial fluid to fill the synovial cavity and further reduce friction
- Synovial fluid reduces friction, moistens the cartilage, and nourishes the cartilage (necessary because cartilage has no blood vessels). Normal synovial fluid has the consistency of raw egg white
- Joint capsule provides stability and protection for the joint
- Bursae help to cushion the joint
What are two characteristics are used to classify synovial joints?
Shape and movement
What are the four major types of synovial joints?
- Hinge joint
- Ball and socket joint
- Pivot joint
- Saddle joint
Describe the characteristics and functions of hinge joints and give an example of this type of joint
- Hinge Joint Characteristics: the convex surface of one bone fits into the concave surface of another bone; can move in only one phase
- Functions: increases or decreases the angle formed by the joint
- Examples: elbow and knee
Describe the characteristics and functions of ball and socket joints and give an example of this type of joint.
- Ball and Socket Joint
- Characteristics: head of one bone fits into depression of another bone; provides the most movement of any joint
- Functions: provides movement in all planes and provides rotational movement around a central axis
- Examples: hip (femur in acetabulum of coxa); shoulder (humerus in glenoid cavity of scapula)
Describe the characteristics and functions of pivot joints and give an examples of this type of joint.
Pivot Joints
Characteristics: one bone pivots on or around another bones
Functions: provides rotation around a central axis
Examples: head of radius rotating around ulna; atlas
rotating (pivoting) around the dens of the axis)
Describe the characteristics and functions of saddle joints and give an example of this type of joint.
Saddle Joint
Characteristics: both bones have concave and convex surfaces (saddle-shaped); concave surface of one bone articulates with concave surface of another bone
Functions: provides movement in two planes
Examples: first metacarpal articulating with the trapezium (a carpal bone)
What are the five types of joint movement? (If given an examples, be able to tell which of the types of joint movement is involved.)
Flexion
Extension
Adduction
Abduction
Circumduction