Chapter 8 - Articulations Flashcards
Synarthroses
Immovable joints
Amphiarthroses
Slightly movable joints
Diarthroses
Freely movable joints
Fibrous Joints
Held together by tough fibrous non-elastic tissue. Lock a joint cavity and provide little or no movement. 3 types: sutures, syndesmoses, and gomphoses.
Sutures
Found only in between membranous bones of the skull. Bones have irregular edges that interlock, leaving a small space which is filled by dense fibrous connective tissue. Allow for growth in youth.
Syndesmoses
Bones are connected by a ligament with much longer fibers. The amount of movement varies with type and length of fiber.
Gomphoses
A fibrous joint that connects the tooth to the bony alveolar sockets of the skull, and immovable joint.
Cartilagenous Joints
Bones are connected by cartilage, no joint cavity, little mobility.
Synchondroses
Bones are connected by hyaline cartilage. Almost always synarthrotic or amphiarthrotic. Ex: epiphyseal plate.
Symphysis
Bones are joined by a pad of fibrocartilage. The articular surfaces are covered by articular (hyaline) cartilage. Joints are reinforced by ligaments which give them strength. Are slightly moveable, give cushioning from impact.
Synovial Joints
Most widely distributed and most complex. Bones usually meet inside a fluid filled capsule
Articular Capsule
Dense fibrous connective tissue continuous with the periosteum of bones. Reinforced by ligaments, it contains fluid, and physically holds the bones together.
Articular Cartilage
A thin layer of hyaline or fibrocartilage. It covers the articular ends of the bone, it makes the ends very smooth which greatly reduces friction.
Synovial Membrane
Lines the articular capsule, produces synovial fluid.
Synovial Fluid
Slippery, viscous fluid. Consists of plasma and hyaluronic acid. If functions to protect, lubricate, and deliver nutrients.
Synovial Bursae
Connective tissue flat sacs, lined by the synovial membrane. Usually found between muscles and tendons and bones that rub against each other. Main function is to reduce friction.
Tendon Sheaths
Resemble a tubular, elongated synovial bursa. Wrap around large tendons that must move a long distance or that are under a large amount of pressure. They reduce friction.
Capsular Ligaments
Intrinsic, found within a capusle
Extracapsular Ligaments
Found outside of the capsule
Intracapsular Ligaments
Deep, deep inside the capsule. Covered by synovial membrane.
Factors Influencing Stability:
Articular Surfaces
Plays a minimal role, unless in a large socked.
Factors Influencing Stability:
Ligaments
Help direct movement and prevent undesirable movement. Play a minimal role, but the more ligaments present, the more stabilizing.
Factors Influencing Stability:
Muscle Tone
The major stabilizing factor. Very important in knee, shoulder, and arches of feet.
Uniaxial Synovial Joint
Permit movement in one plane only. 2 basic types hinge and pivot joints
Hinge Joints
Single transverse axis, like a door. Ex: elbow, knee, interphalangeal.
Pivot Joints
Single axis, the long axis of the bones. Ed: Radioulnar joint.
Biaxial Joints
Permit movement in two planes. 2 types condyloid and saddle
Condyloid Joints
The articular surface of one bones is convex and the other is concave. Allow for angular movement. Ex: Metacarpophalangeal joints.
Saddle Joints
Unique joint. Found in the carpal metacarpal joints of the thumb. The articular surface is saddle-shaped. Allows for opposable thumb.
Multiaxial Joints
Universal joints, they permit movement in many planes. Only one type, ball and socket
Ball & Socket Joints
One bone has a ball that fits into a cup shaped depression on the other bone. Ex: Hips and shoulders.
Nonaxial Joints
One flat, or nearly flat, bone slipping over another. Permits a light sliding movement in several different directions.
Angular Joints
Between two bones, it either increases or decreases the angle between the bones.
Flexion
Decreasing the angle between two bones.
Rotation
A turning movement
Dorsiflexion
Flexion of the ankle
Extension
Increasing the angle between two bones
Supination
Rotation of the hand so that the palm is face up
Pronation
Rotation of the hand so that the palm is face down
Abduction
Movement away from the midline
Adduction
Movement toward the midline
Circumduction
Rotation of a limb so that a cone is circumscribed
Inversion
Medial movement of the food
Protraction
Thrusting the mandible forward
Retraction
Moving the mandible backwards
Elevation
Lifting a body part as the the jaw in chewing
Depression
Lowering a body part as the jaw in chewing
Opposition
Movement of the thumb to oppose the fingers
Tempro-mandibular Joint
Has two joint cavities. Allows for typical hinge movement, opening and closing, and for protraction-retraction, and lateral movement.
Elbow Joint
Joint forms a hinge with the humerus through the trochlea of the ulna. The radius pivots with the ulna. The radius isn’t involved in the extension/flexion of the elbow, but rotates with a ligament to provide pronation/supination of the forearm.
Hip Joint
The socket has an extremely deep socket and is reinforced by internal ligaments that connect the head of the femur to the os coxae. The joint is extremely strong, the strongest of the synovial joints.
Knee Joint
Hinge joint with relatively flat articulating cartilages. Because of the flatness of the joining bones, the joint depends entirely upon ligaments to prevent lateral movement. It is the most vulnerable joint in the body as for as damage is concerned. The most complex joint in the body.
Dislocation
Displacement of the articular surfaces. More common where the articular surfaces don’t lock. Causes damage to the surrounding tissue.
Sprain
Involved damaged ligaments. Either torn or stretched. Results from twisting. Because ligaments are poorly vascularized, they heal slowly. They may repair themselves, if not surgery is necessary.
Cartilage Injuries
Most involve the knee menisci (semilunar cartilage) which are avascular and only rarely can repair themselves
Rheumatoid Arthritis
Degenarition of joints resulting in the fusion of bones. Created a complete loss of mobility, usually affects people over 40. Inflammation of the synovial membrane forms a pannus that clings and destroys the cartilage, ossifiying fibrous tissue and causing crippling.
Osteoarthritis
Most common, also degenerative, wear and tear on overworked joints. Related to aging. Treated by activity, pain medication, and glucosamine. More prominent in women than men.
Arthritis
Degenerative disease which includes a number of different diseases all involving the inflammation of the joints, swelling, and painful movement of joint. More than 100 types.
Gouty Arthritis
Uric acid builds up in the joints. Most common in men, typically the big toe.
Lyme Disease
Bacteria transmitted by ticks that live on deer and mice. Flu-like symptoms, disorientation, joint pain, arthritis. Early on can be treated with antibiotics.
Tendonitis
Inflammation of the tendon sheaths. Caused by overuse.
Bursitis
Bursae become inflamed, swell and cause pain. Caused by excessive stress of friction.
