Lecture 2: Joint Ventures Flashcards
Function of Joints
1) allow skeletal movement; 2) provide mechanical support; 3) hold skeleton together
Other Names for Joint
arthroses; articulations
Joint (Arthrosis)
site where two or more bones meet (may or may not permit movement)
Two bones may be in direct contact with each other or separated by:
cartilage; fluid; fibrous tissue
Joints are classified by..
function (range of motion) and structure
Functional Joint Types
1) synarthrosis; 2) amphiarthrosis; 3) diarthrosis
Synarthrosis
an immovable joint
Types of Synarthroses
1) suture; 2) gomphosis; 3) synchondrosis; 4) synostosis
Gomphosis
a synarthrotic joint between teeth and the jaw bone at which a periodontal ligament holds the teeth (peg joint)
Synchondrosis
a synarthrotic cartilaginous joint within the epiphysis of a bone that binds the diaphysis to the epiphysis
Synostosis
a synarthrotic joint between two fused bones and/or the fusion of three coxal bones
Squamous suture
most lateral suture on a parasagittal plane
Coronal suture
suture across the top of the forehead
Lambdoid suture
most posterior suture on the back of the skull (along the coronal plane)
Aveolar process
thickened ridge of bone that holds teeth in mouth
Amphiarthosis
slightly movable joint
Types of Amphiarthosis
1) syndesmosis; 2) symphysis
Syndesmosis
1) joint in which ligaments connect two bones but limit their motion (between radius and ulna; tibia and fibula); 2) may range from synarthrotic to amphiarthrotic, depending on fiber length
Interosseous Membrane
syndesmosis between the radius and ulna
Pubic Symphysis
symphysis between the coxal bones of the pelvis
Diarthrosis
freely movable joint
Synovial Joint
diarthrotic joint
Location of Synovial Joints
at the end of long bones
Structural Types of Joints
1) bony fusion; 2) fibrous joint; 3) cartilaginous joint; 4) synovial joint
Bony Fusion
more than one bone that fuses together during development; synarthrotic immovable joints (synostoses)
Fibrous Joint
bones joined by dense fibrous connective tissue; skull sutures
Cartilaginous Joint
1) bones united by cartilage; 2) not highly movable; 3) no fluid-filled joint cavity
Synovial Joint
1) bones separated by fluid-filled joint cavity; 2) all diarthrotic; 3) includes all limb joints and most body joints; 4) have six basic characteristics
Frontal Suture
bony fusion at the midline on the skull, between the orbitals
Types of Fibrous Joints
1) Sutures; 2) Gomphoses; 3) Syndesmoses
Sutures
1) rigid interlocking bone edge joints only in the skull; 2) immovable (synarthrotic) for brain protection; 3) contain short connective tissue fibers that allow for growth during youth; 4) ossify and fuse, forming synostoses in middle age
Joint Type: Suture
fibrous synarthrotic joint
Joint Type: Gomphoses
fibrous synarthrotic joint
Joint Type: Syndesmoses
fibrous synarthrotic OR fibrous amphiarthrotic joint, depending on fiber length
Types of Cartilaginous Joints
1) Symphyses; 2) Synchondroses
Symphyses
1) joint at which fibrocartilage unites bone; 2) hyaline cartilage is additionally present to cushion ends of bones; 3) becomes and strong, flexible amphiarthroses
Fibrocartilage
a cartilage type composed of a mix of white fibrous tissue (for strength) and cartilaginous tissue (for flexibility)
Hyaline cartilage
transparent, firm cartilage made partly of collagen and found on many joint surfaces
Joint Type: Pubic Symphysis
cartilaginous amphiarthrotic joint
Coastal Cartilage
bars of hyaline cartilage that are meant to prolong the ribs foreward and contribute to elasticity in the walls of the thorax
Joint Type: Growth Plate Joints
cartilaginous synarthrotic synchodroses
Joint Type: Costal Cartilage
cartilaginous synarthrotic synchodrosis
Six Characteristics of Synovial Joints
1) has a joint capsule
2) presence of articular cartilages
3) a joint cavity
4) synovial fluid
5) accessory structures (cartilage, ligaments, tendons, etc.)
6) sensory nerves and blood vessels
Synovial Features: 1) Joint Capsule
made of two layers: fibrous layer (dense irregular connective tissue) and inner synovial membrane (loose connective tissue that makes synovial fluid)
Synovial Features: 2) Articular Cartilage
hyaline cartilage that prevents crushing of bone ends
Synovial Features: 3) Joint (Synovial) Cavity
small fluid filled space in joint
Synovial Features: 4) Synovial Fluid
1) viscous, slippery filtrate of plasma and hyaluronic acid; 2) lubricates and nourishes articular cartilage; 3) contains phagocytic cells to remove microbes and dibris
Synovial Features: 5) Reinforcing Ligaments
different types of ligaments that are either 1) capsular (thickened part of fibrous layer); 2) extracapsular (outside the capsule); or 3) intracapsular (deep to capsule, covered by synovial membrane)
Synovial Features: 6) Nerves and Blood Vessels
nerves detect pain, monitor position and stretch while capillary beds supply filtrate for synovial fluid
Accessory Synovial Joint Structures: Bursae
sacs lined with synovial membrane and fluid that roll and lessen friction during movement of bones, ligaments, muscles, skin, etc.
Accessory Synovial Joint Structures: Tendon Sheaths
elongated bursa wrapped completely around tendons that are subjected to friction
Accessory Synovial Joint Structures: Menisci (Articular Discs)
fibrocartilage that separates articular surfaces to improve fit of bone ends, stabilize joints and reduce wear and tear
