Joint and Muscle Structure

Question 1

Wolff law

Answer 1

-Bones will adapt based on stress or demands placed on them
-Tissue properties and joint shapes will change as a result of the demands on them

Question 2

Structure types of joints

Answer 2

-Fibrous
-Cartilaginous
-Synovial

Question 3

Joint movement types

Answer 3

• synarthrosis
  -amphiarthrosis
• Diarthrosis

Question 4

Fibrous joint

Answer 4

-join together by fibrous interosseous connective tissue with little to no movement (synarthrosis)

Suture joint: bone edges interlock, one another. Example: frontal and parietal bones.

Gomphosis: Peg in hole joint, tooth in mandible

Syndesmosis: joined by interosseous ligament; radius and ulna

Question 5

Cartilaginous joints

Answer 5

• Connected by fibrocartilage, or Highline cartilage; allows for some movement (amphiarthrosis)

Symphysis: directly joined by fibrocartilage and covered with hyaline ; intervertebral joints and pubic symphysis

Synchondrosis: connected by Highline cartilage; growth, plates, and ribs

Question 6

Synovial joints

Answer 6

• no connective tissue; free to move (diarthrosis)
  -Stabilization provided by capsule, ligaments, muscles
  -Inner layer: provides lubrication and nutrition
  -outer layer, dense a regular connective tissue, good innovation, proprioception

Question 7

Type one joint receptor

Answer 7

Ruffini: senses stretch
-Located in fibrous layer of joint capsules

Question 8

Type two joint receptors

Answer 8

Pacini: compression or changes in hydrostatic pressure of a joint
-Located throughout joint capsule and in deep layer of fat pads

Question 9

Type Three joint receptors

Answer 9

Golgi pressure and forceful joint motion into extremes
-Inner layer of joint capsules, ligaments and tendons

Question 10

Type four unmyelinated, free nerve endings

Answer 10

-Mechanical stress or biomechanical stress
-located around blood vessels, fat pads, collateral ligaments

Question 11

Synovial fluid

Answer 11

-made up of hyaluronate (viscosity to fluid essential for lubrication within the synovial folds.)
-lubricin (cartilage on cartilage lubrication)
-Clear or pale yellow fluid

Question 12

Uniaxial axial joints

Answer 12

Hinge joint: humeroulnar
Pivot joint: proximal radioulnar joint

Question 13

Biaxial joints

Answer 13

Condyloid: radiocarpal joint
Saddle joint: 1st carpometacarpal joint

Question 14

Triaxial joints

Answer 14

Plane joint: intercarpal joint
Ball-and-socket: hip joint

Question 15

Osteokinematics

Answer 15

Movement of bones for physiological joint motion
-Described by plain of movement , axis of motion, and direction

Question 16

Arthrokinematics

Answer 16

Movement of the joint surfaces
Roll: role of one joint surface on another (often occurs with slide)
Slide : linear translation on one or another (often occurs with role)
Spin: rotation

Question 17

Concave moving on convex rule

Answer 17

Roll and glide occur in the same direction

Ex: Tibia moves on femur by rolling, anteriorly and sliding interiorly

Question 18

Convex moving on concave rule

Answer 18

Roll and glide occur in opposite directions
-femur moving on tibia rolls posteriorly while sliding anteriorly

Question 19

Close – packed joint play

Answer 19

• full congruence on surfaces
  -Usually extreme range of motion
  – Joint is compressed, while capsule and ligaments are taught
  No distraction, no further movement available
  – Tightest position

Question 20

Loose – packed joint play

Answer 20

– Incongruent surface
– Usually mid position
– Ligaments and capsule laxity: distraction available
– Rest position

Question 21

Soft end feel

Answer 21

Limited by soft tissues

Elbow flexion

Question 22

Firm end feel

Answer 22

Limited by capsule/ligament structures

Knee extension

Question 23

Hard end feel

Answer 23

Limited by bone

Elbow extension

Question 24

Type one collagen

Answer 24

– Most tension
– Majority of collagen in body

Question 25

Type two collagen

Answer 25

Compression

Question 26

Hyaline cartilage

Answer 26

• type two cartilage
  – Resist compressive forces from joint surfaces
  – Avascular

Question 27

Fibrocartilage

Answer 27

– Mostly type one
– Resist, compressive and tensile forces (meniscus and intervertebral discs
-Limited vascularity

Question 28

Isotropic materials

Answer 28

Display same mechanical behaviors, no matter the direction of the force applied

-Glass cup

Question 29

Anisotropic material

Answer 29

Behave differently, depending on the size and direction of the force

Example: iPad

Question 30

Mechanical behaviors: toe region

Answer 30

Laxity in tissue begins to straighten

Question 31

Mechanical behaviors: elastic region

Answer 31

Can return to original shape and size after being deformed

Question 32

Mechanical behaviors: yield point

Answer 32

Following elastic region, the yield point signals, the point of no return for the tissue

Question 33

Mechanical behaviors: plastic region

Answer 33

Residual deformations of the tissues will be permanent

Question 34

Mechanical behaviors: failure point

Answer 34

Tear or break of tissues

Question 35

Strain

Answer 35

Deformation in response to an externally applied load

(Final length – original length)/original length

Question 36

Brittle

Answer 36

Little deformation required before failure

Question 37

Ductile

Answer 37

Great deformation required before failure

Question 38

Titin

Answer 38

Structural protein within the cycle that maintains position of myosin during muscle contraction

Question 39

Pennation

Answer 39

Orientation of muscle fibers to tendon

Question 40

Length tension relationship

Answer 40

Optimal circle length is 1.2x resting length

Active insufficiency: decreased force capability due to shorten state of agonist, and Lincoln state of antagonist

Question 41

Reverse action

Answer 41

Proximal segment of body moves while the distal segment remains stationary
– Closed chain

Question 42

Pathokinesiology of muscle: Immobilization in short position

Answer 42

– Decrease number of sarcomeres
– Increase sarcomere length, atrophy, and connective tissue

Question 43

Pathokinesiology of muscle: immobilization in long position

Answer 43

– Long cast in knee extension
– increased number of sarcomeres
– Decreased sarcomere length
– Hypertrophy