Types of Joints

3 main types of joints :

A)Fibrous joint
B)Cartilaginous joint
C)Synovial joint

A) Fibrous joint

• Skull sutures
• Syndesmosis - inferior tibio fibular joint
• Gomphosis - Teeth in gum sockets

B) Cartilaginous joint

2 types - 

a) Primary / synchondrosis / hyaline cartilaginous jt

• Ephyphiseo-diaphyseal jt
• Costochondral jt
• 1st chondrosternal jt
• Sphenoccipital jt

b) Secondary / symphyseal / fibroarticular jt

• Intervertebral jt
• Manubriosternal jt
• Pubic symphysis

C) Synovial jt

7 types -

a) Ball and socket jt

• Hip jt
• Shoulder jt
• Incudo stapedial jt
• Talocalcaneonavicular jt

b) condylar jt

• Knee jt
• Atlantoccipital jt
• TMJ

c) ellipsoid jt

• Wrist jt
• Metacarpophalyngeal jts

d) saddle jt

• 1st metacarpocarpal jt
• Sternoclavicular jt
• Incudomalleal jt
• Calcaneocuboidal jt

e) pivot jt

• Superior and inferior radioulnar jt
• Atlanto axial jt

f) hinge jt

• Interphalyngeal jt
• Elbow jt
• Ankle jt

g ) plain jt

• Intercarpal
• Intertarsal
• Interarticular

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Fontanelle of skull,special bones,ossification centres

Anterior Fontanelle of skull

• Also known as foramen bregma
• Between coronal and sagittal suture
• Closes by 18 months post birth

Posterior fontanelle of skull

• Between sagittal and lambdoid suture
• Closes by 4-5 months post birth

Overall there are 6 fontanelles in skull

Sesamoid bones

• Patella
• Fabella
• Pisiform

Pneumatic bones

• It is to reduce weight of bone
• Seen in most skull bones like 

Ethmoid,

Maxilla,

Sphenoid,

Frontal,

Mastoid

Dermal/membranous bones

• Facial bones
• Skull vault

Mandible has 6 ossification centres

Appearance of ossification centers :

• 7th week - femur
• 8th week - tibia,humerus,radius
• 2,3,4 months - illium , ischium , pubis

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Types of Cartilage

3 Main Types of Cartilage

1) Articular cartilage

>> Seen in -
● arytenoid cartilage
● most synovial joints
● cricoid,costal
● throid ,tracheobronchial
● nasal septum and lateral wall
● ephiphyseal plate

>> has no nerves,no vessels,no perichondrium,no ossification

>> provides smooth articular surface

>> degenerated surface cells are replaced by underlying growing cells

2) Elastic cartilage :

>> present in structures reveiving or producing sounds

>> seen in
● auricle and acoustic meatus
● corniculate and cuneiform laryngeal cartilage
● epiglottis

3) Fibroelastic cartilage :

>> seen in
● intervertebral disc
● symphysis
● glenoid labrum and acetabular labrum

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