Joints

Diarthrosis (freely movable)

Amphiarthrosis (slightly movable)

Synarthrosis (little or no movement)

Fibrous

Cartilaginous

Synovial

Collagen Fibers

immovable fibrous joints that bind skull bones together

• serrate – interlocking linesl
• coronal, sagittal, and lambdoid sutures

lap – overlapping beveled edges

• plane – straight, non-overlapping edgesl
• palatine process of the maxillae

attaches tooth to its socket

-held in place by fibrous periodontal ligament

-collagen fibers attach to cementum of tooth and jawbone

-somewhat movable while chewing

bones

joined by collagen fibers (ligament)

-interosseous membrane

-most movable fibrous joint

-ulna/radius and tibia/fibula

-Joint in which two bones are separated by a film ofslippery synovial fluid encased by a joint capsule

-Most are freely movable

-Most structurally complex of all joints

• -Young synovial joints vs. elderly synovial joints
• -quality of life

• Articular capsule encloses joint
• (articular) cavity

• Outer
• fibrous layer continuous with periosteum

• Inner synovial
• layer formed by synovial membrane

Makes synovial fluid

= slippery fluid; feeds cartilages

fills joint (articular) cavity to provide lubrication

hyaline cartilage covering the joint surfaces

law, wrist, sternoclavicular and knee joints

• labsorbs shock, guides bone movements and distributes
• forces

Strengthened by tendons, which attach muscle to bone

Ligament attaches bone to bone

fibrous sacs filled with synovial fluid

between nearby structures so slide more easily past each other

cushions muscles and allows tendons to slide more easily

elongated cylindrical bursae wrapped around a tendon

-especially in the hands and feet

• -when synovial fluid is warmed it becomes less viscous and
• more easily absorbed by articular cartilage

-cartilage swells and becomes a more effective cushion

• -warm-up period helps protect articular cartilage from undue wear
• and tear

-repetitive compression is important to articular cartilage’s nutrition

-compression squeezes out fluid and metabolic waste

• -when compression stops, the cartilage absorbs new synovial
• fluid carrying oxygen and nutrients….like a sponge

• -without exercise, articular
• cartilage deteriorates more rapidly due to lack of oxygen, nutrients, and waste
• removal

-degrees through which a joint can move

a measure of joint flexibility

olecranon process and olecranon fossa

TMJ

-stretching of ligaments increases range of motion

-double-jointed people have long or slack ligaments

-use-it-or-lose-it

nervous system monitors (proprioceptors) joint position and muscle tone-maintaining a state of tension to stabilize joints and body position

Monoaxial joint – one degree of freedom

Biaxial joint – two degrees of freedom

• Multiaxial joint - shoulder joint has 3 degrees of
• freedom

-Some joints cannot be easily classified into any one of the 6 categories of synovial joints – TMJ has aspects of condyloid, hinge, and gliding movements

• 1. Ball-and-Socket Joint
• -multiaxial, head of humerous

• 2. Condyloid Joint
• -biaxial, oval convex, metacarpophalangeal joint

• 3. Saddle Joint
• -biaxial, sternoclavicular joint

• 4.Gliding Joint
• -usually biaxial, bones are flat, amphiarthrosis, ankle bones

• 5. Hinge Joint
• -monoaxial, elbow or knee

• 6. Pivot Joint
• -monoaxial, spins on longitudinal axis, radioulnar joint

decrease the angle of a joint

increases the angle of a joint straightens and returns to the anatomical position

extension beyond 180 degrees or beyond anatomical position

• movement of a part in the
• frontal plane away from the midline of the body

hyperabduction- raise arm over back or front of head

movement towards the midline

hyperadduction-crossing fingers

movement that raises a body part vertically in the frontal plane

• -mandibles are elevated during biting and clavicles during
• a shrug

lowering the body part in the same direction

-lowering the mandible or the shoulders

movement of a body part anteriorly in the transverse (horizontal) plane

-thrusting the jaw forward, shoulders or pelvis forward

movement of a body part posteriorly in the transverse (horizontal) plane

• movement with one end of an
• appendage remains stationary while the other end makes a circular motion

-Sequence of flexion, abduction, extension and adduction movements

-baseball player winding up for a pitch

movement in which a bone spins on its longitudinal axis

-rotation of trunk, thigh, head or arm

• -medial (internal) rotation turns the bone inwards
• -lateral (external) rotation turns the bone outwards

rotation of forearm so that the palm faces anteriorly or upward

inversion and abduction of foot (raising the medial edge of the foot)

rotation of forearm so the palm faces posteriorly or downward

eversion and abduction of foot (raising the lateral edge of the foot)

produces forward-bending movements

straightens trunk or neck

looking up in the sky or bending over backwards

tilting the head or trunk to the right or left of the midline

twisting of the waist or turning of the head

movement in which the toes are elevated - heel strike when walking

movement of the foot so that the toes point downward as in standing on tiptoe

-Supraspinatus tendon

-Infraspinatus tendon

-Teres minor tendon

-Subscapularis tendon

humeroulnar and humeroradial joints + radioulnar joint

trochlea of humerus joins trochlear notch of ulna

supported by collateral ligaments – restrict side-to-side motions

radial (lateral) collateral ligament

ulnar (medial) collateral ligament (Tommy John Surgery)

capitulum of humerus joins the head of the radius

the edge of the head of the radius fits into the radial notch of the ulna

-head of radius held in place by the anular ligament encircling the head

on posterior side of elbow

Largest and most complex

Joint capsule encloses only the lateral and posterior aspects of the knee joint

• Joint cavity contains 2 fibrocartilage “C”-shaped menisci joined by a
• transverse ligament- absorb shock

• Popliteal (posterior knee region) supporting ligaments
• -extracaspular ligaments – external to joint capsule

• 2 collateral ligaments that prevent knee rotation
• -fibular (lateral) collateral ligament
• -tibial (medial) collateral ligament

• 2 intracapsular ligaments –
• -anterior cruciate ligament (ACL) – prevents knee hyperextension ‘locks’ knee during extension
• -posterior curicate ligament (PCL) – stabilized femur

13 Bursa

is a broad term for pain and inflammation of a joint

results from years of joint wear…’wear-and-tear’ arthritis

• - most common form
• - articular cartilage softens and degenerates
• - accompanied by crackling sounds called crepitus
• - bone spurs develop on exposed bone tissue causing pain

is autoimmune attack on joint

replacement of diseased joint with artificial device called prosthesis