Jointin anatomy, a structure that separates two or more adjacent elements of the skeletal system. Depending on the type of joint, such separated elements may or may not move on one another. This article discusses the joints of the human body—particularly their structure but also their ligaments, nerve and blood supply, and nutrition.
Although the discussion focuses on human joints, its content is applicable to joints of vertebrates in general and mammals in particular. For information about the disorders and injuries that commonly affect human joints, see joint disease. In order to describe the main types of joint structures, it is helpful first to summarize the motions made possible by joints. These motions include spinning, swinging, gliding, rolling, and approximation. Spin is a movement of a bone around its own long axis; it is denoted by the anatomical term rotation.
An important example of spin is provided by the radius outer bone of the forearm ; this bone can spin upon the lower end of the humerus upper arm in all positions of the elbow.
When an individual presses the back of the hand against the mouth, the forearm is pronated, or twisted; when the palm of the hand is pressed against the mouth, the forearm is supinated, or untwisted. Pronation is caused by medial inward rotation of the radius and supination by lateral outward rotation. Swing, or angular movement, brings about a change in the angle between the long axis of the moving bone and some reference line in the fixed bone.
Flexion bending and extension straightening of the elbow are examples of swing. A swing to the right or left of one bone away from another is called abduction; the reverse, adduction.
Joint Diagram Templates
Approximation denotes the movement caused by pressing or pulling one bone directly toward another—i. The reverse of approximation is separation. Gliding and rolling movements occur only within synovial joints and cause a moving bone to swing. Joints can be classified in two ways: temporally and structurally. Each classification is associated with joint function. Considered temporally, joints are either transient or permanent.
The bones of a transient joint fuse together sooner or later, but always after birth. All the joints of the skullfor example, are transient except those of the middle ear and those between the lower jaw and the braincase. The bones of a permanent joint do not fuse except as the result of disease or surgery.
Ball And Socket Joint Diagram
Such fusion is called arthrodesis. All permanent and some transient joints permit movement.A joint is where two bones meet. Synovial joints are one of three types of joints in the body. Synovial joints are unique because they contain a fibrous joint capsule with synovial fluid. Hinge and ball-and-socket joints are both types of synovial joints.
Saddle joints are another type of synovial joint.
Types of Joints Diagram
The saddle joint gets its name because the bone forming one part of the joint is concave turned inward at one end and looks like a saddle. Saddle joints are also known as sellar joints. These highly flexible joints are found in various places in the body, including the thumb, shoulder, and inner ear. Unlike hinge joints, such as those between the bones in your fingers, saddle joints have a much greater range of motion than a simple backward-and-forward movement.
Saddle joints have two basic types of movement, known as flexion-extension and abduction-adduction. When you bend your elbow, you decrease the angle between your upper arm and your forearm. This is an example of flexion. This is an example of extension. Abduction and adduction are movements related to the midline of a structure.
For example, spreading your fingers wide moves them away from the midline down the center of your hand.How to replace Driver's side CV axle shaft 06 - 11 Honda Civic
Adduction is a return toward the midline. Some saddle joints are also capable of combining flexion-extension and abduction-adduction movements. The prime example of a saddle joint is the trapeziometacarpal joint at the base of your thumb.
It connects the trapezium and the metacarpal bone of your thumb. The flexion-extension and abduction-adduction characteristics of this joint allow your thumb to spread out wide to help grasp large objects, while also allowing it to move inward, to tightly touch each of your other fingers.
This is also a fairly common site for osteoarthritiswhich can cause pain, weakness, and stiffness in your thumb and inner wrist. This joint is where your clavicle collarbone meets your manubrium, which is the upper part of your sternum breastbone.
It allows you to raise your arm over your head, among other movements, and also supports your shoulder. The ligaments that surround this joint are some of the strongest in your body, which make the sternoclavicular joint hard to injure. However, high-impact collisions, falls, or car accidents can all damage your sternoclavicular joint.
This joint is located in your inner ear, where it connects two small bones called the malleus and incus. Head injurieslong-term ear infectionsand inserting foreign objects too far into your ear can all cause damage to this joint and affect your hearing. However, the ones you do have are crucial to many daily activities, from listening to music to grasping things in your hand.
Cartilage cushions joints and helps them work smoothly. But degeneration of cartilage from a lifetime of moving can lead to osteoarthritis OA. As you get older, the cartilage in your joints can start to become worn, especially in your knees, hips, and hands. Losing this cartilage leads to…. Did you know that your skeleton is made up of over bones?
Learn more fun facts about the skeletal system. Did you know that your body contains more than muscles? Learn more fun facts about the muscular system. Not getting enough calcium in your diet can lead to fragile, brittle bones that are more prone to fractures and disease. Find out which foods can help…. Drinking enough water can help you burn fat and increase your energy levels.You may return an unused and uninstalled part in its original packaging.
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When extra point offers are combined, total points earned will be less than the combined point totals for each individual offer. Drag link ball joint A is part of the steering mechanism that connects the pitman arm and the drag link.
Hover to Zoom. In Stock. Add to cart. For zip codes near: Edit. Member Exclusive Not a member? Part Information. This drag link ball joint part number A is for lawn tractors. Wear work gloves to protect your hands when installing this part. Part Number. Will this part fit my model? What's a model number and where do I find it? Other Information. Top Brands. Top Categories. Television Parts Seiki.Flowcharts outlining the standard anatomical classification of joints.
There are two major schools of classification: structural and functional. Although different, there is significant overlap between their descriptions and these diagrams aim to demonstrate this.
Understanding the classification of joints is important in understanding the related pathology. In general, the more stable a joint is the less mobile it will be, and conversely the more mobile a joint is the more easily it can be dislocated. The classification of joints has two schools: the structural and functional systems. This is a common question in anatomical examinations where a candidate will be expected to give both the structural and functional classification of a given joint.
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About Blog Go ad-free. Classification of joints - diagram Case contributed by Dr Jeffrey Cheng. Diagnosis not applicable.
From the case: Classification of joints - diagram. Loading images Loading Stack - 0 images remaining.The neck is the start of the spinal column and spinal cord. The spinal column contains about two dozen inter-connected, oddly shaped, bony segments, called vertebrae. The neck contains seven of these, known as the cervical vertebrae. They are the smallest and uppermost vertebrae in the body.
The spinal column extends from the base of the skull to the pelvis. It protects and houses the spinal cord — the long bundle of nervous tissue that transmits neural signals to the brain and rest of body. It runs from the back of the head to the small of the back. It is more prominent in men than in women. The thyroid cartilage that makes up the body of the larynx, or voice box, creates this prominence, and it develops during puberty.
Speech is made possible by critical structures within the neck. The larynx houses the vocal cords, or vocal folds. Sound is generated when these folds come together to produce vibrations. Its movement also manipulates pitch and volume. The larynx is located where the pharynx, the back of the mouth and nasal cavity, divides into the trachea the tube that carries air to the lungs and the esophagus the tube that carries food to the stomach.
That branch occurs near the base of the neck near the collarbones. The distal phalanges are one of three types of finger bones. The human hand and wrist are comprised of three different bone groups. The carpals are…. The heel is the portion of the human body that lies at the bottom-rear part of each foot. Its exterior shape is formed by the calcaneus, also known as…. The elbow is one of the largest joints in the body. In conjunction with the shoulder joint and wrist, the elbow gives the arm much of its versatility….Joints can be classified by the type of the tissue present fibrous, cartilaginous or synovialor by the degree of movement permitted synarthrosis, amphiarthrosis or diarthrosis.
In this article, we shall look at the classification of joints in the human body. A fibrous joint is where the bones are bound by a tough, fibrous tissue. These are typically joints that require strength.
Sutures are immovable joints synarthrosisand are only found between the flat, plate-like bones of the skull. There is limited movement until about 20 years of age, after which they become fixed and immobile. They are most important in birth, as at that stage the joints are not fused, allowing deformation of the skull as it passes through the birth canal.
Gomphoses are also immovable joints. They are found where the teeth articulate with their sockets in the maxilla upper teeth or the mandible lower teeth. They are comprised of bones held together by an interosseous membrane. The middle radioulnar joint and middle tibiofibular joint are examples of a syndesmosis joint. In a cartilaginous jointthe bones are united by fibrocartilage or hyaline cartilage.
There are two main types: synchondroses primary cartilaginous and symphyses secondary cartilaginous. In a synchondrosis, the bones are connected by hyaline cartilage. These joints are immovable synarthrosis. An example of a synchondrosis is the joint between the diaphysis and epiphysis of a growing long bone. Symphysial joints are where the bones are united by a layer of fibrocartilage.
They are slightly movable amphiarthrosis. Fig 2 — Adjacent vertebral bodies are connected by fibrocartilage: an example of a symphysis. A synovial joint is defined by the presence of a fluid-filled joint cavity contained within a fibrous capsule.
Synovial joints can be sub-classified into several different types, depending on the shape of their articular surfaces and the movements permitted:. Once you've finished editing, click 'Submit for Review', and your changes will be reviewed by our team before publishing on the site. Cookies help us deliver the best experience to all our users. The find out more about our cookies, click here.
Fibrous Joints A fibrous joint is where the bones are bound by a tough, fibrous tissue. Fibrous joints can be further sub-classified into sutures, gomphoses and syndesmoses.Many patients want to use the right technical terms when talking with their physician, and this can certainly improve the efficiency of your office visit. The CMC joint of the thumb is located at the junction point of the thumb and the wrist. Break down the words in the name, carpometacarpal, and you get carpo- wrist and metacarpal hand bone.
This joint is commonly affected by arthritis. The MP joint of the thumb is the middle joint of the thumb, located between the CMC joint and the tip of the thumb. Break down the words in the name, metacarpophalangeal, and you get metacarpo- hand bone and phalangeal finger bone. This joint moves a lot in some people and just a little in other people. Compare MP thumb joints around your family and you may find some big differences.
Sometimes this joint is injured when you jam it in a skiing or sports injury. This causes the joint to pop out of place and tear a ligament. The IP joint of the thumb is at the tip of the thumb. Important tendons attach on the bottom and top of this joint and move the tip of your thumb back and forth. Tendons move joints — when a tendon is ripped off the bone, the joint no longer moves normally. Familiarity with the language of the joints of the thumb will help streamline your visit with a hand specialist or other health care provider.
These splints also called braces can be ordered online or purchased locally. If you splint your thumb, be sure not to wear it for more than weeks straight. You also want to come out of the splint 3 times a day and do some gentle range of motion exercises to avoid stiffness for about two minutes or so. A mallet finger is the name for a ruptured torn tendon at the tip of the finger. A tendon rupture is where a tendon […]. This is abnormal — in a normal thumb, the majority of the motion is through the CMC carpometacarpal joint, at the base of the thumb.
Lawn Tractor Drag Link Ball Joint 923-0448A
When the CMC joint […]. Bones in children are different from bones in adults. They break differently and they respond differently to injury. Some fractures occur both in adults and kids — some fractures occur only in children. Forearm fractures occur in both, with some important differences. This article will cover some of the basics of forearm fractures in kids. The most common tumor in the finger is a ganglion cyst.
A ganglion cyst is simply a fluid-filled sac. It can be visible from the outside or buried deep underneath the skin. What is a mucous cyst? Ganglion cysts […]. My thumb hurts in the joint! Categories anatomy announcements arthritis bone health carpal tunnel syndrome common problems current events Famous Hands and Arms FAQ fractures hand surgery injections media appearances news nonsurgical treatment nutrition philosophy of medicine prevention sports surgery tests thumb Uncategorized video wrist surgery.