Tag: joints in the human body

The hinge joint is a joint in which a convex part of one bone fits into a concave part of another, allowing motion in only one plane. In hinge joint, the two bones open and close in one direction only (along one plane) like a door, such as a knee joint.

Pivot joint is a synovial joint, which permits uniaxial movement of bone about one axis of rotation. In pivot joint central bony pivot is surrounded by collar of bone and ligament. The movements possible are supination, pronation and rotation. Examples of pivot joints are proximal radioulnar joint and atlanto-axial joint.

The humerus and the radioulna together form the elbow which is the hinge joint. The distal end of the humerus articulates the proximal end of the radius and ulna. The humeroulnar joint is also a part of the elbow and is a hinge joint whereas the proximal radioulnar and the distal radioulnar is a pivot joint. Thus, the correct answer is option D.

The type of joint found at the shoulder is called a ball and socket which also found in the hip

The ball and socket joint is the type of synovial joint present between the bones having structures like ball and socket. This joint is found in the shoulder joint. Head of the humur acts as the ball and the glenoid cavity of scapula acts as the socket.

• Joints are points of contact between bones, or between bones and cartilages.
  
• Synovial joints are characterized by the presence of a fluid-filled synovial cavity between the articulating surfaces of the two bones. These joints help in locomotion and many other movements. 
• A hinge joint (ginglymus) is a joint in which the articular surfaces are molded to each other in such a manner as to permit motion only in one plane.
• The knee joint and elbow is a hinge joint/ ginglymoid i.e a type of synovial joint. 
• So, the correct answer is 'Elbow and Knee'.

A synovial joint is a connection between two bones which consists of a cartilage lined cavity filled with fluid. The knee joint is the biggest synovial joint in the human body. At the junction of the knee, the large femur bone of the thigh connects to both the tibia and fibula of the leg, as well as to the patella or knee cap. So, the correct answer is 'Knee joint'.

• Joints are points of contact between bones, or between bones and cartilages.
  
• Synovial joints are characterized by the presence of a fluid-filled synovial cavity between the articulating surfaces of the two bones. These joints help in locomotion and many other movements.
• Synovial joints are freely movable joint. Hence synovial fluid is present in freely movable joint.
• So,the correct answer is 'Freely movable joints'.

Synovial fluid is the pale yellow fluid that is present in every joint of the human body. It helps the bone able to slide past each other without causing damage to the ends of the bone. It means that synovial fluid lessens the friction in ball and socket joint. So, the correct answer is 'Synovial fluid'.