Chapter 8 Flashcards
What are synarthrotic joints?
Synarthrotic joints are immovable joints.
What connecting material is usually found in fibrous joints?
Fibrous joints are typically connected by collagen fibers.
Which classification of joints are all classified as diarthrotic?
Synovial joints are all classified as diarthrotic, meaning freely movable.
What is the difference between abduction and adduction?
Abduction is movement away from the midline of the body.
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Adduction is movement towards the midline of the body.
What is the special term for extension of the ankle joint?
Extension of the ankle joint is called plantar flexion. This is when you point your toes.
What are the two main types of cartilaginous joints?
Synchondrosis: joined by hyaline cartilage
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Symphysis: joined by fibrocartilage
What is the source of synovial fluid?
The synovial membrane, which consists mostly of cells called synoviocytes, produces synovial fluid.
How does synovial fluid provide nutrients and remove waste products from the articular cartilage?
Synovial fluid is forced in and out of the cartilage as the joint moves, acting as a pumping mechanism to replenish nutrients and remove waste products.
What is a bursa (plural bursae)?
A bursa is a small, fluid-filled sac that acts as a cushion between structures that might rub against each other.
Where is the acetabular labrum located and what is its function?
The acetabular labrum is a fibrocartilage ring that surrounds the acetabulum (socket) of the hip joint. It helps to deepen the socket and improve stability
What is sciatica?
Sciatica is pain that radiates down the leg, caused by irritation of the sciatic nerve. This can occur due to a variety of factors, including a herniated disc or a tight piriformis muscle.
What is hip dysplasia?
Hip dysplasia is an abnormal development of the hip joint where there is inadequate coverage of the femoral head by the acetabulum. This can lead to an increased risk of dislocation.
What is the glenoid labrum?
he glenoid labrum is a ring of fibrocartilage that surrounds the glenoid fossa (socket) of the shoulder joint. It helps to deepen the socket and provide stability.
In which direction does the shoulder most commonly dislocate?
The shoulder most commonly dislocates inferiorly (downward). This is because there is less muscular and ligamentous support on the inferior aspect of the joint.
What is prepatellar bursitis?
Prepatellar bursitis is an inflammation of the bursa located between the skin and the patella (kneecap). It is commonly known as “housemaid’s knee” because it can be caused by repeated kneeling.
What can happen if there is a tear in one of the collateral ligaments of the knee?
: A tear in a collateral ligament can lead to instability in the knee joint. The knee may displace either medially or laterally, depending on which ligament is torn.
What are osteophytes and how can they affect joint movement?
Osteophytes, also known as bone spurs, are bony projections that can develop on the edges of bones. They can develop due to osteoarthritis and can interfere with normal joint movement.
What is one potential cause of patellar dislocation?
One potential cause of patellar dislocation is a shallow patellar surface on the femur, which provides inadequate support for the kneecap.
How can joints be categorized structurally?
Joints can be categorized structurally based on the type of material that holds the bones together:
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Fibrous: Dense connective tissue
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Cartilaginous: Hyaline cartilage or fibrocartilage
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Bony: Bone has replaced other material
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Synovial: Joint capsule
How can joints be categorized functionally?
Joints can be categorized functionally based on their degree of mobility:
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Synarthrotic: Immovable
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Amphiarthrotic: Slightly movable
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Diarthrotic: Freely movable
What is the trade-off between joint strength and flexibility?
There is an inverse relationship between joint strength and flexibility.
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Increased strength (resistance to dislocation) comes at the cost of decreased flexibility (ease and range of movement)
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Increased flexibility comes at the cost of decreased strength.
What are the parts of a synovial joint?
Articular cartilage: Covers the bone surfaces
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Joint capsule: A fibrous connective tissue structure that encloses the joint cavity
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Synovial membrane: Lines the joint capsule and produces synovial fluid
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Synovial fluid: Lubricates the joint and nourishes the articular cartilage
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Ligaments: Connect bone to bone and reinforce the joint capsule
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Menisci (singular: meniscus): Fibrocartilage pads that provide cushioning and stability (knee joint)
How do the parts of a synovial joint enhance movement?
Articular cartilage: Provides a smooth, low-friction surface for movement
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Synovial fluid: Lubricates the joint surfaces, allowing for smooth gliding
How do the parts of a synovial joint enhance stability?
Joint capsule: Encloses the joint cavity and provides support
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Ligaments: Connect bone to bone, restrict excessive movement, and reinforce the joint capsule
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Menisci: Provide cushioning and stability, deepen the articulation, and help guide movement (knee joint)
Why can diarthrotic (synovial) joints produce varying degrees of movement?
Diarthrotic joints can produce varying degrees of movement in one or more planes because of the shape of the articulating bone surfaces (joint surfaces).
Pivot
Allows rotation around a single axis (Example: atlantoaxial joint - rotation of the head
Hinge:
Allows flexion and extension in one plane (Example: elbow joint
Condyloid (Ellipsoid):
Allows movement in two planes (biaxial) (Example: atlanto-occipital joint - nodding the head
Saddle:
Allows movement in two planes and a slight rotational movement (biaxial) (Example: carpometacarpal joint of the thumb - opposition
Plane (Gliding):
Allows gliding or sliding movements (Example: intercarpal joints
Ball-and-Socket:
llows a wide range of motion in all three planes (multiaxial) (Example: hip joint
How is the hip joint structurally organized?
Ball-and-socket joint between the head of the femur and the acetabulum of the pelvic bone
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Deep socket and strong ligaments contribute to stability
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Acetabular labrum (fibrocartilage ring) deepens the socket
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Reinforced by strong ligaments (iliofemoral, pubofemoral, ischiofemoral) that twist and tighten in a standing position
How does the structure of the hip joint influence its flexibility?
The ball-and-socket structure allows for a wide range of motion, including flexion, extension, abduction, adduction, and rotation.
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However, the deep socket and strong ligaments limit flexibility compared to the shoulder joint
What are the roles of ligaments and tendons in reinforcing the hip joint?
Ligaments (iliofemoral, pubofemoral, ischiofemoral) connect the femur to the pelvic bone, preventing excessive movement and reinforcing the joint capsule.
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Tendons of muscles surrounding the hip joint also contribute to stability by holding the joint in place.
How is the shoulder joint structurally organized?
Ball-and-socket joint between the head of the humerus and the glenoid fossa of the scapula
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Shallow socket and less bony coverage compared to the hip joint
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Glenoid labrum (fibrocartilage ring) deepens the socket
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Reinforced by the rotator cuff muscles and their tendons
How does the structure of the shoulder joint influence its flexibility?
The shallow socket and minimal bony restrictions allow for a wide range of motion, making it the most flexible joint in the body.
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However, this flexibility comes at the cost of stability, making the shoulder joint prone to dislocation.
What are the roles of ligaments and tendons in reinforcing the shoulder joint?
Ligaments surround the joint capsule and provide some support.
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Tendons of the rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis) play a crucial role in stabilizing the shoulder joint, holding the humeral head in the glenoid fossa
How is the knee joint structurally organized?
Modified hinge joint between the femur, tibia, and patella
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Condyles of the femur articulate with the relatively flat tibial plateaus
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Medial and lateral menisci (fibrocartilage pads) deepen the articulation and provide cushioning and stability
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Reinforced by multiple ligaments, including the cruciate ligaments (anterior and posterior) and collateral ligaments (medial and lateral)
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Patellar ligament connects the patella to the tibia
How does the structure of the knee joint influence its flexibility?
Primarily allows flexion and extension (hinge-like motion)
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Some degree of rotation is possible when the knee is flexed
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Ligaments and menisci provide stability and guide movement, limiting flexibility compared to the hip or shoulder.
What are the roles of ligaments and tendons in reinforcing the knee joint?
Ligaments:
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Cruciate ligaments (anterior and posterior) prevent anterior-posterior displacement of the tibia relative to the femur.
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Collateral ligaments (medial and lateral) prevent excessive side-to-side motion.
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Tendons:
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Quadriceps tendon inserts on the patella and helps extend the knee.
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Patellar ligament connects the patella to the tibia and also contributes to knee extension.
What are some common types of injuries and disorders that can affect the hip joint?
Arthritis: Degeneration of articular cartilage, leading to pain and reduced mobility
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Hip dysplasia: Abnormal development of the hip joint, leading to increased risk of dislocation
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Sacroiliitis: Inflammation of the sacroiliac joint, causing lower back pain
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Sciatica: Pain radiating down the leg due to irritation of the sciatic nerve, potentially caused by a tight piriformis muscle
What are some common types of injuries and disorders that can affect the shoulder joint?
Dislocation: Humeral head dislocates from the glenoid fossa, often inferiorly
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Rotator cuff tears: Tears in the tendons of the rotator cuff muscles, causing pain and weakness
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Impingement syndrome: Compression of tendons or bursa in the subacromial space, leading to pain and limited movement
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Bursitis: Inflammation of the bursae surrounding the shoulder joint, causing pain and swelling.
What are some common types of injuries and disorders that can affect the knee joint?
Ligament tears: Tears in the ACL, PCL, MCL, or LCL, causing instability and pain
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Meniscus tears: Tears in the medial or lateral meniscus, leading to pain, clicking, and limited movement
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Bursitis: Inflammation of the bursae, especially the prepatellar bursa (“housemaid’s knee”)
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Arthritis: Degeneration of articular cartilage, leading to pain, stiffness, and reduced mobility
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Patellar dislocation: Displacement of the patella from its normal position
