Articulations

What is an articulation?

A point where two bones meet

How are joints classified structurally?

By the connective tissue binding bones and presence or absence of a joint cavity

What are the three structural joint types?

Fibrous, Cartilaginous, Synovial

How are joints classified functionally?

By the amount of movement allowed

What are the three functional joint types?

Synarthroses, Amphiarthroses, Diarthroses

What is a fibrous joint?

Bones joined by dense connective tissue; no joint cavity

Examples of fibrous joints?

Sutures, Gomphosis, Syndesmosis

What functional type are most fibrous joints?

Synarthroses

What is a suture?

Immovable fibrous joint between flat skull bones

What is a syndesmosis?

Fibrous joint uniting two bones

Example of a syndesmosis?

Interosseous Membrane between radius and ulna

What is a gomphosis?

Fibrous joint anchoring a tooth to its socket

What is a cartilaginous joint?

Bones joined by cartilage; no joint cavity

What are the two types of cartilaginous joints?

Synchondroses and symphyses

What is a synchondrosis?

Joint joined by hyaline cartilage

Example of a synchondrosis?

Epiphyseal plate and Costochondral Joints

What functional type is a synchondrosis?

Synarthrosis

What is a symphysis?

Joint joined by fibrocartilage

Examples of symphyses?

Intervertebral discs and pubic symphysis

What functional type is a symphysis?

Amphiarthrosis

What is a synovial joint?

Joint with synovial cavity

What functional type are all synovial joints?

Diarthroses

What characterizes diarthroses?

Freely movable joints

Explain stability vs mobility relationship in synovial joints?

Increased mobility results in decreased stability and vice versa

What is a subluxation?

Partial dislocation of a joint

What is a dislocation?

Complete displacement of bones at a joint

Why is the shoulder more easily dislocated than the hip?

There is a ligament in the hip joint

What is the acetabulum?

Deep socket of the hip joint

What is the glenoid cavity?

Shallow socket of the shoulder joint

What unique ligament stabilizes the hip joint?

Iliofemoral ligament

Where does the iliofemoral ligament attach?

Ilium to femur

What ligaments stabilize the knee?

Patellar tendon, LCL, MCL, ACL, PCL, ALL, and medial/lateral menisci

What is the function of the ACL?

Prevents anterior movement of tibia relative to femur

What is the function of the PCL?

Prevents posterior movement of tibia relative to femur

What is the function of the MCL?

Prevents lateral movement of the tibia

What is the function of the LCL?

Prevents medial movement of the tibia

What is the function of the meniscus?

Shock absorption

What type of cartilage is the meniscus?

Fibrocartilage

How long do artificial joints typically last?

15–25 years

What are bursae?

Fluid-filled sacs that reduce friction between tissues

What are tendon sheaths?

Elongated bursae that reduce friction around tendons

What are the six types of synovial joints?

Plane, Hinge, Pivot, Condylar, Saddle, Ball & Socket

What is a plane joint?

Flat surfaces that glide past each other

Example of a plane joint?

Intercarpal joints (wrist)

What is a hinge joint?

Movement in one plane only (flexion and extension)

Example of a hinge joint?

Elbow

What is a pivot joint?

A joint allowing rotation around a single axis

Example of a pivot joint?

Median Atlantoaxial joint (C1 and C2 joint)

What is a condylar joint?

Oval surfaces allowing biaxial movement

Example of a condylar joint?

Knuckles

What is a saddle joint?

Concave and convex surfaces allowing biaxial movement

Example of a saddle joint?

Thumb joint

What is a ball-and-socket joint?

Spherical head fitting into a socket allowing for multiaxial movement

Examples of ball-and-socket joints?

Hip

What term describes the amount of movement in synovial joints?

Diarthrotic