What are the functions of joints? The basic structure and function of joints

The main function of the joint is movement. They have a variety of forms of movement, and there are great differences in their range of motion. The normal range of motion of each joint is affected by age, gender, fat and thinness, and exercise, and the general rule is that young, female, thin, and regular exercisers have a larger range of motion for their joints; Elderly, male, obese, and inactive people have a smaller range of motion for their joints.

The movement forms of joints are basically divided into 3 groups: flexion and extension, adduction (the joint is close to the midline of the body) and abduction (the joint is away from the midline of the body), internal rotation and external rotation. For example, the elbow joint of the upper limb can act and stretch a group of movements, and the wrist joint can do two sets of actions of flexion and extension, adduction and abduction; The shoulder joint can perform three sets of movements: flexion and extension, adduction and abduction, internal rotation and external rotation.

The place where bones are connected is the joint, which can move is called "movable joint", and immovable is called "immovable joint". Generally speaking, joints refer to "moving joints". Although there are many kinds of joints in the human body, their basic structure is nothing more than joint surfaces, joint cavities, and joint cavities.

There are many joints in the human body, such as the knuckles, elbows, and knees that can do flexion and extension exercises, the radial-ulnar joints that can do rotational movements, and the shoulder joints and hip joints that can do both flexion and extension exercises.

It can be seen that the joints play the role of fulcrum in movement, which can not only help us move, but also make our hands and feet stretch freely! At the same time, when we jump from a height, the joints act as cushions.

Joints exist for movement, and there are many forms that allow us to achieve movement. In daily life, we should pay attention to protecting our joints, usually pay attention to the joints to avoid cold and keep warm, and we can eat something like Jianli polyaminic chondroitin to supplement joint nutrition.

2. Intensive lecture on the basics of arthritology in the open course of medical examination - the auxiliary structure of joints.

1. Leverage: In the movement of the human body, the bone is the lever, the joint is the fulcrum, when the skeletal muscle contractions, the force acts on the lever, and a variety of actions can be completed through the fulcrum to achieve the desired purpose. In the process of accomplishing these feelings, the joints become the hub or fulcrum of the movement.

2. Cushioning effect: when people are walking, running or being stamped by external forces, joints can play a cushioning role. For example, when running, the weight of the body is cushioned to reduce the burden on the bones; When subjected to external force, after buffering, the damage suffered by the person can be greatly reduced and reduced, so as to protect the body and make it less damaged.

1. Articular surface.

The articular surface is generally one concave and one convex, because the uneven and convex structure is conducive to the stability of the joint and can reduce the chance of joint dislocation (dislocation). The surface of the joint is cartilage tissue, which has a certain elasticity and toughness, and can withstand greater pressure and impact. On the surface of the articular cartilage, there is a thin layer of fluid called synovial fluid.

The function of synovial fluid is mainly to reduce the friction on the surface of the articular cartilage, and play the role of lubrication and cushioning. At the same time, synovial fluid is the main nutrient of articular cartilage** and plays an important role in maintaining the integrity of articular cartilage.

2. Joint capsule.

The joint capsule is a closed structure, and its function is to wrap the joint, connect the city as a whole, and maintain the stability of the joint during movement.

3. Joint cavity.

The space within the joint capsule is the joint cavity, and one of the most important structures is the articular disc (cartilage plate). The disc sits like a cushion washer between two bones, reducing shock and vibration between the bones of the joint. The disc in the knee joint is called the meniscus, which makes the knee joint more stable and flexible.

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Joint cavity: a closed and potential cavity surrounded by the synovial layer of articular cartilage and joint capsule, with a small amount of synovial fluid, which can lubricate the joint and reduce friction, and the cavity is negative pressure, which is conducive to the stability of the joint.

Answer: The place where the bones are connected is called the joint, the movable joint is called the "movable joint", and the immovable joint is called the "immovable joint". The joints mentioned here refer to the moving joints, such as the shoulders, elbows, fingers, hips, knees and other joints of the limbs.

From a functional point of view, the mobility of joints with good stability is limited to a certain extent; The stability of joints with high mobility is affected to a certain extent.

There are many joints in the human body, and the joints in different positions play different functions, of course, most of them play a role in helping the human body bend and walk.

Joints act as fulcrums in movement.

Flexion and extension, adduction, and abduction.