jAnatomy Lecture Notes Chapter 9

I. classification

A. by function -

1. synarthrosis - immovable

2. amphiarthrosis - slightly movable

3. diarthrosis - freely movable

B. by structure - material attaching bones together

1. fibrous -.dense c.t., no joint cavity

a. suture - very thin, short fibers synostosis - ossification of fibrous c.t. in a suture joint

b. syndesmosis - ligament (the longer the fibers the more movement is possible)

c. gomphosis - periodontal ligament holds teeth in alveoli

2. cartilaginous - cartilage, no joint cavity

a. synchondrosis - hyaline cartilage

b. symphysis - fibrocartilage

3. synovial - joint capsule and ligaments

II. structure of a synovial joint

A. bone and articular cartilage (hyaline) • articular cartilage cushions bone ends by absorbing compression stress

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B. articular capsule

1. fibrous capsule - dense irregular c.t.; holds bones together

2. synovial membrane - areolar c.t. with some simple squamous e.; makes synovial fluid

C. joint cavity and synovial fluid

1. synovial fluid consists of: • fluid that is filtered from capillaries in the synovial membrane • glycoprotein molecules that are made by fibroblasts in the synovial membrane 2. fluid lubricates surface of bones inside joint capsule

D. ligaments - made of dense fibrous c.t.; strengthen joint • capsular • extracapsular • intracapsular

E. articular disc / meniscus - made of fibrocartilage; improves fit between articulating bones

F. bursae - membrane sac enclosing synovial fluid found around some joints; cushion ligaments, muscles, tendons, skin, bones

G. tendon sheath - elongated bursa that wraps around a tendon

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III. movements at joints

flexion

extension

abduction

adduction

circumduction

rotation

inversion

eversion

protraction

retraction

supination

pronation

elevation

depression

opposition

dorsiflexion

plantar flexion

gliding

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IV. types of synovial joints

plane

hinge

pivot

condyloid

saddle

ball and

socket

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V. tibiofemoral joint

A. bones

• femur

• tibia

• patella

B. ligaments – prevent hyperextension

fibular collateral

tibial collateral

oblique popliteal

arcuate popliteal

anterior cruciate

posterior cruciate

C. menisci • C-shaped discs of fibrocartilage • attached to tibial condyles • thicker on outside edges • medial and lateral • guide femoral condyles, help prevent side to side motion

D. principal bursae

1. suprapatellar

2. prepatellar

3. infrapatellar

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