chapter 8 - joints

Question 1

what are the 3 functional classes of joints?

Answer 1

synarthroses - no movement
ampphiarhtroses - slight movement
diaarthroses - free movement

Question 2

what are the 3 structural classes of joints?

Answer 2

fibrous - joined by fibrous CT
cartilaginous - joined by cartilage
synovial - inside fluid filled cavity

Question 3

What are the three types of fibrous joints?

Answer 3

SUTURES - bones joined by short fibers (cranial bones). Allows for growth during youth.

SYNDESMOSES - bones joined by ligaments. Allows none to slight movement (distal tibiofibular joint)

GOMPHOSES:
-peg in socket (no movement). teeth anchored in sockets

Question 4

What are the two types of cartilaginous joints?

Answer 4

SYNCHONDROSES:
-bones joined together by a pad of hyaline cartilage
-are synarthrotic
ex sternum with first ribs

SYMPHYSES:
-bones joined together by pad of fibrocartilage
-strong/flexible amphiarthroses
ex pubic symphysis

Question 5

List and briefly describe the 6 major structures of synovial joints.

Answer 5

ARTICULAR CARTILAGE: covers ends of bones

JOINT (SYNOVIAL) CAVITY: contains lubricating fluid

ARTICULAR (JOINT) CAPSULE: encloses joint articulation
-2 layers, outer is dense-irregular CT and inner is synovial membrane

SYNOVIAL FLUID: produced by synovial membrane. Lubricates and nourishes joint cavity

LIGAMENTS: reinforce outside of capsule

RICH NERVE/VESSEL SUPPLY:

• nerves to detect pain
• capillary beds produce filtrate for synovial fluid

Question 6

List and describe the other 3 structures that may be found in synovial joints

Answer 6

BURSAE and TENDON SHEATHS:
fibrous sacs lined with synovial membrane and filled with synovial fluid. Ease movement by reducing friction

FATTY PADS: between fibrous capsule and bone

MENISCI: cartilage wedges or discs that stabilize the joint

Question 7

What affects the stability of synovial joints?

Answer 7

Shape
Number and location of ligaments
Muscle tone - determines tautness of tendons across joint

Question 8

What is inversion/eversion?

Answer 8

inversion: turning the sole medially
eversion: turning the sole laterally

Question 9

What is protraction/retraction?

Answer 9

protraction: anterior movement of the jaw
retraction: posterior movement of the jaw

Question 10

What is elevation/depression?

Answer 10

elevation: movement up
depression: movement down

ex jaw

Question 11

What is opposition?

Answer 11

pushing tip of fingers against tip of thumb

Question 12

What are the 4 classes of movement?

Answer 12

non axial - movement along no plane
uniaxial - along one plane
biaxial - along two planes
multiaxial - along all planes

Question 13

List the 6 types of synovial joints and describe them as uni, bi, or multiaxial.

Answer 13

PLANE: Non axial
flat articular surfaces slide over each other
ex intercarpals

HINGE: uniaxial
ex elbow

PIVOT: uniaxial
rounded end of one bone into a sleeve/ring of another
ex proximalradioulnar

CONDYLOID: biaxial
both articular surfaces are oval
ex metacarpal/phalangeal joints

SADDLE: biaxial
greater freedom of movement than condyloid
ex thumb carpal/metacarpal

BALL-AND-SOCKET: multiaxial
most freely moving of all
ex shoulder and hip joints

Question 14

What is the easiest joint to dislocate in the body?

Answer 14

temporomandibular

Question 15

What are the 3 common joint injuries?

Answer 15

SPRAINS: stretched/torn ligaments
partial tears will heal themselves slowly
complete tears require surgical repair

CARTILAGE TEARS:
cartilage has poor healing qualities so will require surgical repair (rarely heals itself)
fragments can cause locking/binding

DISLOCATIONS (luxations):
bones are forced out of alignment
accompanied by sprains, inflammation, and joint immobilization

Subluxation: partial dislocation of joint

Question 16

List the three inflammatory and degenerative conditions.

Answer 16

BURSITIS: inflammation of bursa usually by blow/friction. Treated with rest, ice, and if severe anti-inflammatory drugs

TENDONITIS: inflammation of tendon sheaths typically by overuse. Treat same as bursitis

ARTHRITIS: damage to joints. many types
most common crippling disease
acute: bacteria (antibiotics)
chronic: osteo, rheumatoid, and gouty

Question 17

Describe osteoarthritis. (OA)

Answer 17

Wear and tear arthritis (85% of all ppl develop this)

more common in men below 50 and woman over 50

• more cartilage is destroyed than is replaced.
• exposed bone ends thicken, enlarge, form bone spurs, and restrict movement

treatment: moderate activity, mild pain relievers, capsaicin cream

Question 18

Describe rheumatoid arthritis (RA)

Answer 18

autoimmune disease of unknown cause
affects 3x more woman than men

• Inflammatory blood cells migrate to the joint and release inflammatory chemicals.
• inflamed synovial membrane thickens into a pannus which erodes cartilage forming scar tissue until bone ends connect

Treatment:

conservative: aspirin, long term use of antibiotics, and physical therapy
progressive: anti-inflammatory drugs or immunosuppressants

response modifier drugs neutralize inflammatory chemicals

Question 19

Describe gouty arthritis

Answer 19

deposition of uric acid crystals in joints/soft tissue followed by inflammation
typically affects the joint at the base of great toe and it goes untreated ends will gradually fuse

treatment: drugs, plenty of water, avoid alcohol

Question 20

Lyme disease

Answer 20

caused by bacteria from tick bite
symptoms: skin rash, flu like symptoms and foggy thinking, may lead to joint swelling, pain and arthritis

treatment: antibiotics