- Written By Manisha Minni
- Last Modified 25-01-2023
Did you know that an adult human has \(206\) bones in the body? How are these bones attached to each other? Have we ever thought about how we can walk? What helps us in lifting objects? Joints make all these movements possible. We cannot imagine our daily life without Joints.
In the absence of joints, our body will become stiff, and we will not be able to do any activity. Joints produce flexibility to the skeleton by connecting the bones. All joints have a different way of functioning, and they are involved in other forms of movement.In this article, we will discuss in detail about Joints, Definition, Classification, Functions, etc. Continue reading to know more.
Definition of Joints
A Joint or Articulation is the point where two or more bones or a bone and a cartilage are attached to the body.
Joints are involved for the purpose of allowing body parts to move. Joints hold our bones together and help the skeletal system to complete its functions. The three main joints in the body are fibrous, cartilaginous, and synovial.
Classification of Joints Based on Structure
Joints are classified in two ways based on the structure. First, as per structure, joints are classified into three categories: Fibrous, Cartilaginous, and Synovial.
Fibrous Joints
- Fibrous Joints do not allow movements; therefore, they are Immovable joints or Fixed joints or Synarthrosis.
- These joints connect by dense connective tissue consisting of primary collagen fibres and do not have a joint cavity.
- They protect internal organs, strength to the body and stability to our body structure.
- Syndesmosis, Gomphosis, and Sutures are different types of fibrous joints.
(a) Sutures are found in our skull bones with dentate margins. - Other examples of a fibrous joint are the rib cage, pelvic girdle, backbone, and upper jaw.
Cartilaginous Joints
- This is also known as Amphiarthrosis, which allows limited movement.
- In this type of joints, the bones involved are joined together with the help of cartilages.
- The joint between the adjacent vertebrae in our vertebral column is of this pattern.
- Synchondroses and Symphyses are two types of cartilaginous joints.
- The sternocostal joint is an example of the cartilaginous joint.
- The pubic symphysis of the pelvis is a cartilaginous joint.
(a) This is found in the pubic regions of the right and left hip bones are strongly anchored to each other by fibrocartilage.
Synovial Joint
- Synovial joints or Diarthrosis have a fluid-filled synovial cavity and irregular dense tissues that form the articular capsule.
- This is a perfectly movable joint and allows movements in one or more planes.
- This joint helps in locomotion and many other movements.
- A synovial capsule covers a synovial joint; the synovial fluid secreted by the synovial capsule lubricates and nourishes the joint.
- There are six types of synovial joints mentioned in the table below.
| Types of Synovial Joints | Structure | Function | Location |
| Ball and Socket Joint | It is formed by fixing bones into the cavity of other bones. | Ball and socket joints provide movement in multiple planes. | Shoulder and hip joints are examples of this type of joint. |
| Saddle Joint | This joint is formed between whose articulating surfaces have both concave and convex regions. | The saddle joint shows movement in two planes. | The saddle joint is located between the carpal and metacarpal of the thumb. |
| Hinge Joint | This joint is formed by the articulation of two or more bones. | Hinge joints provide movement in one plane. | Hinge joints are found in the knee and elbow joints. |
| Condyloid Joint | This joint is the modified form of the hinge joint. | Condyloid joints allow movement in two planes. | Condyloid joints are found in wrist bones. Joints between metacarpals and phalanges are of this type. |
| Pivot Joint | It consists of the rounded end of one bone that fits into the ring of another bone. | The pivot joint helps in rotation around the axis. | Pivot joints are present between the atlas and axis and wrist bones. |
| Gliding Joint | This joint between two bones where the surface of the bones is almost flat enables the bones to slide over each other. | The gliding joint allows sliding movements. | Gliding joints are found between the carpals. |
Types of Joints Based on Functions
Joints can be classified into three categories based on functions: immovable or Synarthrosis joints, partly movable or Amphiarthrosis joints, and movable or Diarthrosis joints.
| Types of Joints | Movement |
| Immovable | This type of joint does not allow any movement.Example: skull sutures, articulation of bony sockets and teeth. |
| Partially Movable | This type of joint allows limited movement.Example: distal joint between tibia and fibula and the vertebrae of the spine. |
| Movable | This type of joint allows movements in one or more axes. Example: elbow, shoulder, and ankle. |
Joints and Their Movement
These are the few common joints and their movements.
| Joint | Type | Movement |
| Elbow | Hinge | Flexion and Extension |
| Knee | Hinge | Flexion and Extension |
| Hip | Ball and Socket | Flexion, Extension, Abduction, Adduction, rotation, and Circumduction |
| Shoulder | Ball and Socket | Flexion, Extension, Abduction, Adduction, rotation, and Circumduction |
Additional Information: Lever System
A lever system is a rigid bar where movement takes place along the joint on a fixed point called the fulcrum of the lever. Joints in the human body also function as levers. Let us have a look at how the joints can be classified as levers. The three types of levers are:
| Type of Lever | Example |
| First-Class Lever (fulcrum between effort and load). | Found between the atlas vertebra and occipital bone of the skull. When the head moves up, the common is the fulcrum, contraction of the back muscle is the effort and the facial portion of the skull acts as load or resistance. |
| Second Class Lever (load is between fulcrum and effort) | Found in the ankle joint. When the human body is moved upwards on toes, the ball of the foot is the fulcrum, the contraction of calf muscles to pull the heel upward is the effort, and the body is the load or resistance. |
| Third Class Lever (effort is between fulcrum and load) | Found in the elbow of the forearm. At the time of biceps curl, the elbow joint is the fulcrum, the contraction of the biceps brachii muscles is the effort, and the weight of the forearm is the load or resistance. |
Function of Joints
These are the main functions of joints:
- It permits stability to the skeletal system.
- It helps in walking, running, lifting things, grasping, and gripping an object.
- It protects vital organs of our body by providing a protective enclosure.
- It helps in multiple movements of our organs.
Disorder of Joints
Common disorders of the Joints are:
- Arthritis: Inflammation of joints. It results in pain, swelling, and stiffness of the joint, and over a period, it can damage the joint. This can be of many types like Rheumatoid arthritis, Osteoarthritis, etc.
- Gout: Inflammation of joints due to accumulation of uric acid crystals. This is also called gouty arthritis.
- Bursitis: Inflammation of fluid-filled sac (Bursa) that cushions the joints.
Do You Know?
Summary
A Joint or Arthrosis is a part where two or more bones meet. In general, a human body has around 300 joints altogether, which works in a specific way to complete different functions of the human body. Fibrous, cartilaginous, and synovial are the three types of joints in our body. The basic function of joints is to provide structural stability and to allow movement.
Frequently Asked Questions
Q.1. How to make bones and joints strong?
Ans: Bones and joints can be made stronger by eating an anti-inflammatory diet and maintaining body weight.
Q.2. How many joints are there in the human body?
Ans: There are around 250 to 350 joints in the human body.
Q.3. Why do bone joints make a sound?
Ans: The sound comes from the air bubble in the synovial fluid that gets trapped and then released during movements.
Q.4. How to lubricate joints?
Ans: We can lubricate joints by consuming a lot of water and food containing omega-3 fatty acids.
Q.5. What is arthritis?
Ans: Inflammation of joints. It causes swelling, stiffness, and pain in the joint and over a period it can damage the joint.
Q.6. What is the strongest joint in the body?
Ans: The strongest joint in the body is the Hip.
Q.7. What is the study of joints called?
Ans: Study of joints is called Arthrology (Greek Arthros = joints; Logos = study).
Q.8. What is the anatomy of a joint?
Ans: Synovial joints have a fluid-filled synovial cavity and irregular dense tissues that form the articular capsule. A synovial capsule covers a synovial joint; the synovial fluid secreted by the synovial capsule lubricates and nourishes the joint.
Q.9. What is Kinesiology?
Ans: Kinesiology is the scientific study of human or non-human body movement. Kinesiology addresses physiological, biomechanical, and psychological dynamic principles and mechanisms of movement.
Q.10. What is a joint function?
Ans: These are the main functions of joints:
1. It permits stability to the skeletal system.
2. It helps in walking, running, lifting things, grasping, and gripping an object.
3. It protects vital organs of our body by providing a protective enclosure.
4. It helps in multiple movements of our organs.
Now that you are provided with all the necessary information on Joints in Human and we hope this detailed article is helpful to you. If you have any questions about this article, ping us through the comment box below and we will get back to you as soon as possible.
FAQs
Joints: Definition, Classification and Functions? ›
Joints, also known as articulations, are a form of connection between bones. They provide stability to the skeletal system as well as allowing for specialized movement. Joints can be classified: Histologically, on the dominant type of connective tissue. ie fibrous, cartilaginous, and synovial.
What are the classification of joints and their functions? ›Joints are thus functionally classified as a synarthrosis or immobile joint, an amphiarthrosis or slightly moveable joint, or as a diarthrosis, which is a freely moveable joint (arthroun = “to fasten by a joint”).
What is the definition and function of joints? ›A joint is the part of the body where two or more bones meet to allow movement. Every bone in the body – except for the hyoid bone in the throat – meets up with at least one other bone at a joint. The shape of a joint depends on its function. A joint is also known as an articulation.
What is the classification of a joint? ›The structural classification divides joints into fibrous, cartilaginous, and synovial joints depending on the material composing the joint and the presence or absence of a cavity in the joint. The functional classification divides joints into three categories: synarthroses, amphiarthroses, and diarthroses.
What are the 3 classifications of joints? ›Histologically the three joints in the body are fibrous, cartilaginous, and synovial. Functionally the three types of joints are synarthrosis (immovable), amphiarthrosis (slightly moveable), and diarthrosis (freely moveable).
What is the function of the synovial joint? ›1 – Synovial Joints: Synovial joints allow for smooth movements between the adjacent bones. The joint is surrounded by an articular capsule that defines a joint cavity filled with synovial fluid. The articulating surfaces of the bones are covered by a thin layer of articular cartilage.
Why are joints important in the human body? ›Joints connect bones. They provide stability to the skeleton, and allow movement. There are different types of joints.
What are 5 functions of joints? ›Ball and socket joints are capable of producing movements across multiple axes, including flexion, extension, abduction, adduction, and rotation. The shoulder and hip joints are two examples of ball and socket joints.
What are the 3 joints and their functions? ›- A pivot joint allows one bone to rotate around another. ...
- A hinge joint allows back and forth movement like the hinge of a door. ...
- A saddle joint allows two different types of movement. ...
- A plane joint also called a gliding joint, allows two bones that glide over one another.
The joints help us to rotate our shoulder, bend our knees and elbows, swivel our neck and more. By definition, a joint is a point where two bones meet to provide a framework that permits movement. Bones are attached to one another by tissues called ligaments.
What is the most common joint classification? ›
The most common type of joint is the diarthrosis, which is a freely moveable joint. All synovial joints are functionally classified as diarthroses.
What is the classification of joints based on quizlet? ›Functional classification of joints is based on: the amount of movement allowed by the joint.
What is a joint in anatomy? ›A joint is a point where two bones make contact. Joints can be classified either histologically or functionally. Histological classification is based on the dominant type of connective tissue, and functional classification is based on the amount of movement permitted.
How many structural classifications of joints are there? ›Structural classification of joints categorizes them based on the type of tissue involved in formation. There are three structural classifications of joints: fibrous, cartilaginous, and synovial.
How many joints are there in the body? ›The joints connect bone to bone, and there are 360 joints in our bodies. Bone mass reaches maximum density in our late 20's and early 30's. As we age, our bones may weaken causing them to be more prone to fractures, so taking care of our bone and joint health is vital.
What is an example of a fibrous joint? ›The fibrous joints unite bones with the help of collagen-rich fibrous tissues. Some of the examples where these joints are present include skull bones, the bones of the ankle, between teeth roots, and socket.
What do cartilaginous joints do? ›Cartilaginous joints are a type of joint where the bones are entirely joined by cartilage, either hyaline cartilage or fibrocartilage. These joints generally allow more movement than fibrous joints but less movement than synovial joints.
What is an example of a hinge joint? ›- elbow.
- knee.
- finger joints (interphalangeal joints)
- toe joints (interphalangeal joints)
- ankles (tibiotalar joint)
Some of the typically most important joints in body are considered to be the knee, hip, and shoulder. They're all constructed differently to balance the relationship between mobility and stability.
What are joints made of? ›Joints are movable connections between two bones. Each joint is made up of the surfaces of the bones involved, a joint cavity and a joint capsule. The joint surfaces (articular surfaces) of the bones are covered with a layer of cartilage. This layer is between 0.2 and 0.5 mm thick, and up to 6 mm thick on the kneecap.
What are the most used joints in the human body? ›
The TMJ joint is the most used joint in the body. It has – like the knee – an articular disc within it!
Why are joints called joints? ›The noun joint came into English through the French word joindre, meaning “to join.” Use joint to describe the point where two things connect, or join. A joint on your body allows for movement — you can look at your finger to see how that works.
Where are all the joints in your body? ›| Common Joint Name | Bones of the Joint |
|---|---|
| Wrist | Radius, ulna and carpals |
| Sacroiliac | Sacrum and ilium |
| Hip | Femur and pelvis |
| Knee | Femur, patella, tibia and fibula |
Answer and Explanation: The following is not a functional classification of joints D. Arthrofibrosis.
What is the function of the ball and socket joint? ›What are Ball and Socket Joints? The smooth joint, with a hemispherical head that fits within a cuplike depression, is called the ball and socket joint. This type of joint helps in rotational or circular movements, as one bone is captivated into the hollow space of another bone. This is the most freely moving joint.
What are the three classifications of joints based on movement quizlet? ›The functional classification joint is based on the degree of movement that they allow. The three functional classes are: 1) synarthroses, which are totally immovable, 2) amphiarthroses, which have slight movement, and 3) diarthroses, which are freely moveable joints.
What is the functional classification of joints the intervertebral joint? ›The structural classification of the intervertebral disc joint is a fused, fibrocartilaginous symphysis. However, functionally, it is considered an amphiarthrosis which permits a limited amount of movement.
What is the difference between fibrous cartilaginous and synovial joints? ›There are three types of joints in the human body: fibrous, cartilaginous, and synovial. Fibrous joints are held together by dense connective tissue, cartilaginous joints are held together by cartilage, and synovial joints are free-moving and enclosed in a capsule.