Untitled Flashcards Set

Joints

Where bones connect, also called articulations.

Functions of joints

Enable movement and provide stability.

Synarthroses

Immovable joints.

Amphiarthrosis

Slightly movable joints.

Diarthroses

Freely movable joints.

Fibrous joints

Joints where bones are joined by dense fibrous connective tissue, lacking a joint cavity.

Sutures

Rigid, interlocking joints of the skull that permit growth in early life.

Gomphoses

Peg-in-socket joints, such as teeth in alveolar sockets, held by the periodontal ligament.

Synchondroses

Bar or plate of hyaline cartilage connects bones, typically immovable.

Symphyses

Joints where fibrocartilage connects bones, allowing slight movement.

Synovial joints

Joints where bones are separated by a fluid-filled joint cavity, and all are freely movable.

Articular cartilage

Covers the ends of bones in synovial joints, made of hyaline cartilage.

Synovial fluid

A slippery fluid made from plasma and hyaluronic acid that lubricates and nourishes cartilage.

Articular capsule

Two-layered structure surrounding a synovial joint.

Reinforcing ligaments

Stabilize the joint and can be capsular, extracapsular, or intracapsular.

Nerves and blood vessels in joints

Nerves detect pain and joint position, while capillaries supply fluid components.

Joints

Also called articulations, where bones connect.

Functions of Joints

Enable movement and provide stability.

Structural Classifications of Joints

Classified based on connective material and whether a cavity is present.

Functional Classifications of Joints

Classified based on movement the joint allows.

Synarthroses

Immovable joints.

Amphiarthrosis

Slightly movable joints.

Diarthroses

Freely movable joints.

Fibrous Joints

Bones joined by dense fibrous connective tissue, with no joint cavity; most are immovable.

Sutures

Rigid, interlocking joints of the skull that permit growth in early life.

Syndesmosis

Two parallel bones connected by ligaments, allowing for varying movement.

Gomphoses

Peg-in-socket joints, with the only examples being teeth in alveolar sockets.

Cartilaginous Joints

Joints where bones are united by cartilage, allowing little to no movement.

Synchondroses

Bar or plate of hyaline cartilage connecting bones, almost all are immovable.

Symphyses

Fibrocartilage connects bones in symphysis joint, slightly movable.

Synovial Joints

Joints with bones separated by a fluid-filled cavity, all are freely movable.

Articular Cartilage

Covers bone ends, made of hyaline cartilage to prevent bones from crashing against each other.

Synovial Fluid

A slippery fluid that lubricates and nourishes cartilage.

Articular Capsule

Two-layered structure that surrounds the joint.

Reinforcing Ligaments

Stabilizes the joint; can be capsular, extracapsular, or intracapsular.

Bursae

Flattened sacs that reduce friction between tissues.

Tendon Sheaths

Elongated bursae that wrap around tendons, common in wrist and ankle tendons.

Meniscus

Wedge-shaped pads of fibrocartilage that improve the fit between bone ends.

Joint Stability

How well a joint stays together during movement, influenced by bone shape, ligaments, and muscle tone.

Articular Surface Shape

Shallow or poorly fitting surfaces lead to less stability, while deep sockets (e.g., hip) provide more stability.

Joint Stability Factors

The main factors influencing joint stability include the shape of bone surfaces and the presence of ligaments.

Role of Ligaments

More ligaments contribute to joint stability, but they may stretch and aren't the primary stabilizers.

Articular Cartilage

Covers bone ends in synovial joints, reducing friction.

Joint Cavity

Space filled with synovial fluid in synovial joints, allowing for movement.

Articular Capsule

Two-layered enclosure surrounding a synovial joint.

Diarthroses

All synovial joints are classified as diarthroses, meaning they are freely movable.

Bursae

Flattened sacs filled with synovial fluid that reduce friction between tissues.

Tendon Sheaths

Elongated bursae that wrap around tendons, common in areas with high friction.

Meniscus

Fibrocartilage pads that improve joint fit, distribute weight, and enhance stability.

Types of Joint Movement

Joint movements include gliding, angular (flexion, extension, etc.), and rotation.

Nonaxial Movement

Movement does not occur around an axis, primarily involves slipping or gliding.

Uniaxial Joints

Joints that allow movement in one plane around one axis.

Biaxial Joints

Joints allowing movement in two planes around two axes.

Multiaxial Joints

Joints that permit movement in or around all three planes.

Circumduction

A movement that involves flexion, abduction, extension, and adduction, describing a cone in space.

Examples of synarthrosis

Sutures synchondroses, gomphosis

Syndesmosis parts

Distal tibia and fibula joint

Symphysis

Pubic symphysis and intervertebral discs