Synovial joints Test 2

Question 0

understand how bones act as levers. what r the classes and wat r there adv’s and disadv’s

Answer 0

STRENGTH OR SPEED NOT BOTH
1st class lever
• Fulcrum is in between resistance and effort
○ E_____F______R
2nd class lever
• Fulcrum will b on one of the ends resistance is in middle and effort is on the other end
○ E_______R_______F
§ Effort arm > Resistance arm = high mechanical adv. = strength
§ Advantage for strength or 2nd class lever would b for starting a race
§ Disadvantage for not built for speed
3rd class lever most in body
• Fulcrum on a end resistance on the other end and effort in the middle
○ R____E_____F
§ Effort arm < rest. Arm = low mechanical adv. = speed
§ Speed - quicker faster distance . Effort applied = a quicker result

Question 1

describe the anatomy of synovial joints

Answer 1

• Synovial joints hav the following
		○ Articular cartilage
			§ Hyaline cartilage 
		○ Joint cavity 
			§ Synovial fluid
		○ Articular capsule 
			§ Synovial membrane
				□ Lines the inside of the joint cavity (in between cavity and fibrous layer)
			§ Fibrous layer 
				□ Composed of dense irregular 
		○ Reinforcing ligaments  

	○ How r they stabilized 
		§ Muscles tht cross the joint 

• Excessories 
	○ Bursae - flattened fibrous sac lined w/ synovial membranes and containing synovial fluid 
	○ Tendon sheath - elongated bursa tht wraps completely around a tendon

Question 2

describe the types of synovial joints and their movements

Answer 2

• Plane joints non-axial joints
○ Articular surfaces
○ Allows slipping and slidding
○ Carpals and tarsals
• Hinge joint Uni-axial
○ Cylinder projection
§ Flex and extend
□ Elbow knee and interphalangeal joints
• Pivot joints Uni-axial
○ Joint between the axis and the dens and the proximal radioulnar joint
• Condylar (ellipsoid) joints Bi-axial joints
○ Wrist joints , metacarpophalangeal (knuckle) joints
• Saddle joints Bi-axial
○ Joint of thumb
• Ball and socket joints Multi-axial joints
○ Shoulder / hip

Question 3

understand the following movements? gliding rotation dorsiflexion plantar flexsion circumduction elevation depression protraction retraction

Answer 3

Gliding - ulnar / radial deviation
Rotation - turning of a joint of a bone around a long axis . Hip and shoulder joints
Dorsiflexion of the foot - point foot up
Plantar flexion of foot - point foot down
Circumduction - combination of movements to complete a circle. Rotator cuff muscles
Elevation - mandible up
Depression - mandible down
Protraction -pushing out. towards the front of body
Retraction - pushing toward the back of body

Question 4

understand these disorders Osteoarthritis and Rheumatoid arthritis (RA)

Answer 4

○ Osteoarthritis - metabolic disorder of the articular cartilage and subchondral bone
§ Causes wear and tear ana tomic inflammatory and metabolic
§ Imbalance between stress aplied to a joint and joints ability to withstand the stress
§ Either the load is exeessive or the articular cartilage bone is defective
○ Rheumatoid arthritis(RA) - systemic autoimmune disease of unknown cause
§ Immune cells attracted to synovial membrane and fluid
§ Genetic predisposition?