articular system and joints Flashcards
Name the 3 types of cartilage found in the body and give an example of where each type of cartilage can be found
The three types of cartilage are:
1. Hyaline cartilage - costal cartilage of ribs, articular cartilage in joints
2. Elastic cartilage - external ear
3. Fibrocartilage - intervertebral discs
Describe the structure and function of fibrous and cartilaginous joints
Fibrous Joints:
- Structure: Bones are united by dense connective tissue with no joint cavity.
- Function: Generally immovable or allow limited movement.
Cartilaginous Joints:
- Structure: Bones are united by hyaline or fibrocartilage, with no joint cavity.
- Function: Allow limited movement and provide strength and shock absorption.
Describe the general features of a synovial joint
- Articular cartilage: Hyaline cartilage covering the ends of bones, reducing friction.
- Joint cavity: A fluid-filled space between the bones, allowing movement.
- Synovial membrane: Lines the joint cavity and secretes synovial fluid for lubrication.
- Joint capsule: A fibrous capsule enclosing the joint, reinforced by ligaments.
- Ligaments: Connect bones and provide stability to the joint.
- Accessory structures: Include bursae, menisci, and fat pads, which help reduce friction and improve joint stability.
Describe the factors that affect joint mobility and stability
- Bone Structure/Shape: The shape of bones determines movement type and range. For example, ball-and-socket joints allow more mobility than hinge joints.
- Ligament Strength and Tension: Ligaments stabilize joints; more or tighter ligaments increase stability, though excessive tension can limit movement.
- Muscle Arrangement and Tension: Surrounding muscles control movement and support joints. Well-developed muscles improve stability, while imbalances affect motion.
- Soft Tissue Contact: Soft tissues (like muscles and fat pads) can restrict or enable movement by filling or expanding joint space.
- Hormones: Hormones like relaxin can increase joint flexibility, affecting mobility and stability, especially during pregnancy.
- Disuse: Lack of activity weakens muscles and ligaments, reducing both stability and mobility.
What components make up the articular system?
The articular system consists of joints, associated ligaments, and accessory structures.
What is a joint or articulation?
A joint or articulation is a point of contact between two bones, bones and cartilage, or bones and teeth.
How are joints classified structurally?
Joints are classified based on:
(1) The presence or absence of a synovial cavity (space between articulating bones).
(2) The type of connective tissue that binds the bones together (e.g., cartilage).
What type of tissue is cartilage, and where is it located?
Cartilage is a resilient, semirigid connective tissue found in parts of the skeleton
How is cartilage nourished, and why?
Cartilage is nourished via diffusion because it lacks blood vessels, lymphatic vessels, and nerves.
Why do younger people have more cartilage?
Younger people have more cartilage due to the process of endochondral ossification during bone development.
What is the role of articular cartilage?
Articular cartilage provides smooth surfaces for joints, facilitating movement.
What is the most common type of cartilage, and where is it found?
Hyaline cartilage is the most common type and covers bony articular surfaces.
What role does hyaline cartilage play in fetal development?
Hyaline cartilage serves as the model for the early fetal skeleton.
What is the primary structural component of hyaline cartilage?
Hyaline cartilage contains moderate amounts of collagen.
Which type of cartilage is highly flexible, and where is it found?
Elastic cartilage is highly flexible and is found in the external ear, auditory tube, and parts of the larynx.
What structural feature characterizes elastic cartilage?
Elastic cartilage contains bundles of elastic fibers.
Where is fibrocartilage found in the body?
Fibrocartilage is found in specialized joints such as discs, menisci, and labra, contributing to articular surfaces.
What structural component gives fibrocartilage its strength?
Fibrocartilage contains substantial amounts of collagen.
What is fibrocartilage composed of?
Fibrocartilage is a mix of fibrous tissue and hyaline cartilage.
What are the three main types of joints or articulations?
Synovial, fibrous, and cartilaginous joints.
What characterizes synovial joints?
Synovial joints are moveable, with bones united by a joint or articular cavity and often supported by associated structures.
How are bones united in fibrous joints, and how does this affect movement?
Bones in fibrous joints are united by fibrous tissue, and the degree of movement depends on the length of the fibers.
What is the main function of cartilaginous joints?
Cartilaginous joints provide strength and shock absorption.
What type of tissue unites bones in cartilaginous joints?
Bones in cartilaginous joints are united by hyaline cartilage or fibrocartilage.