Anatomy of a Joint
Anatomy of a Joint
Joints are the areas where 2 or more
bones meet. Most joints are mobile, allowing the bones to move. Joints consist of the
Cartilage. This is a type of tissue that covers the surface of a bone at a
joint. Cartilage helps reduce the friction of movement within a joint.
Synovial membrane. A tissue called the synovial membrane lines the joint and
seals it into a joint capsule. The synovial membrane secretes a clear, sticky
fluid (synovial fluid) around the joint to lubricate it.
Ligaments. Strong ligaments (tough, elastic bands of connective tissue)
surround the joint to give support and limit the joint's movement. Ligaments connect
Tendons. Tendons (another type of tough connective tissue) on each side of a
joint attach to muscles that control movement of the joint. Tendons connect muscles
Bursas. Fluid-filled sacs, called bursas, between bones, ligaments, or other
nearby structures. They help cushion the friction in a joint.
Synovial fluid. A clear, sticky fluid secreted by the synovial membrane.
Meniscus. This is a curved part of cartilage in the knees and other
What are the different types of joints?
There are many types of joints, including joints that don’t move in adults, such as the suture joints in the skull. Joints that don’t move are called fixed. Other joints may move a little, such as the vertebrae. Examples of mobile joints include the following:
Ball-and-socket joints. Ball-and-socket joints, such as the shoulder and
hip joints, allow backward, forward, sideways, and rotating movements.
Hinge joints. Hinge joints, such as in the fingers, knees, elbows, and
toes, allow only bending and straightening movements.
Pivot joints. Pivot joints, such as the neck joints, allow limited
Ellipsoidal joints. Ellipsoidal joints, such as the wrist joint, allow all
types of movement except pivotal movements.
Online Medical Reviewer: Diane Horowitz MD
Online Medical Reviewer: Marianne Fraser MSN RN
Online Medical Reviewer: Raymond Kent Turley BSN MSN RN
Date Last Reviewed:
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