Understanding Human Body Joints: Structure and Function

Diarthrotic joints can be classified into specific categories based on their range of motion and structure. These incorrect answers do not accurately represent the six groups that diarthrotic joints can be divided into, as described in the correct answer.

Diarthrotic joints permit considerable movement in various directions, unlike fixed or limited movement joints.

A hinge/ginglymus joint allows movement in only one plane, similar to a door hinge. The elbow is an example of this type of joint as it allows movement in only one direction.

A pivot/trochoid joint is a type of joint that allows rotation around a single axis. The atlas/axis joint in the neck is a classic example of a pivot joint, as it allows the head to rotate from side to side or to nod up and down.

Gliding/plane joints allow for limited side-to-side and back-and-forth movements. The articular processes between vertebrae are an example of this type of joint, allowing for smooth gliding motions.

An ellipsoid/condyloid joint allows movement in two planes, flexion/extension, abduction/adduction, and circumduction. The wrist joint is an example of this type of joint as it allows for a wide range of movements.

The joint capsule is made up of various components such as fibrous connective tissue, ligaments, articular cartilage, tendons, synovial membrane, and bursa, not muscles, nerves, blood vessels, skin.

Fibrous connective tissue functions to line with synovial membrane, fit over ends of 2 bones like a sleeve, hold bones together, but permit movement, unlike the functions described in the incorrect answers.

Ligaments are specialized connective tissue structures that connect bones together and provide stability to joints.

Articular cartilage is the layer of connective tissue that serves as a cushion between bones at a joint, providing smooth movement and protecting the bones from rubbing against each other.

Tendons are made of connective tissue and primarily function to connect muscles to bones, allowing for movement.

The synovial membrane is responsible for secreting synovial fluid to reduce friction and enable smooth movement within joints.

A bursa is a small fluid-filled sac in the body that helps reduce friction between tissues such as tendons and bones. They are not related to trees, knee surgeries, or ancient Greek philosophers.

Synarthrotic joints are joints that are immovable or have limited movement, such as the joints found in the skull and teeth sockets.

A synchondrosis is a specific type of joint in the human body that is characterized by its fibrocartilaginous nature and limited movement capabilities.

Synarthrotic joints are immovable or allow very limited movement between bones, providing stability and support rather than motion.

Synarthrotic joints are immovable joints found in the body. The sutures of the cranial bones are an example of a synarthrotic joint as they are fibrous joints that fuse the bones of the skull together. The knee joint, shoulder joint, and elbow joint are examples of diarthrotic or freely movable joints.

Syndesmosis is characterized by minimal movement between bones due to strong ligamentous structures holding them together.

Amphiarthrotic joints are also known as cartilaginous joints because they are connected by cartilage and allow for limited movement.

Ball and socket joints allow for a wide range of motion in multiple directions. The shoulder and hip joints are prime examples of this type of joint, enabling circular motion and rotation.

A saddle joint, also known as a reciprocal-reception joint, is a type of synovial joint in which two bones can move in such a way as to allow movement in all directions. The example provided in the correct answer showcases this unique joint between the metacarpal bone of the thumb and the carpal bone of the wrist, allowing for a wide range of motion.

Joints can be classified based on their degrees of movement and the type of connective tissue involved. The correct classifications are synarthrotic (immovable), amphiarthrotic (slightly movable), and diarthrotic (freely movable) joints.

A synarthrotic joint is characterized by limited to no movement due to the presence of fibrous connective tissue that tightly binds the articulating bones together. The incorrect answers describe different types of joints that do not align with the characteristics of a synarthrotic joint.

A syndesmosis joint is defined as a type of fibrous joint where two parallel bones are joined by connective tissue. The correct answer, the inferior tibiofibular articulation, is an example where the tibia and fibula are connected by interosseous membrane.

A joint capsule is a thin, fibrous sac that contains fluid and encloses a synovial joint to provide structure and stability to the joint.

An amphiarthrotic joint is characterized by the presence of cartilage connecting the articulating bones, allowing for limited movement.

Diarthrotic joints are also known as synovial joints because they are characterized by the presence of synovial fluid within the joint cavity, allowing for a wide range of motion.

Synarthrotic joints are also known as fibrous joints because they are held together by fibrous connective tissue. Cartilaginous joints have cartilage between the bones, ball-and-socket joints allow for a wide range of motion, and hinge joints allow movement in one direction only.

Amphiarthrotic joints allow for limited movement, not as much as freely movable synovial joints but more than immovable fibrous joints.