Exam #1 Flashcards
1
Q
Fibroblast
A
- basic cell of most CT: found in tendon, ligament, skin, and bone
- mostly type I collagen
- resist tensile forces
- produces extracellular matrix
- can differentiate into difference cells depending on different loads, functions, etc.
2
Q
Chondroblast
A
- differentiated fibroblast found in cartilage
- mostly type II collagen
- resist compressive forces
3
Q
Osteoblast
A
- differentiated fibroblast found in bone
- produces type I collagen and hydroxyapatite (inorganic material, “crystals”- gives bones its compressive strength; however, may also lead to tendon degeneration (RTC)
- osteoblast–osteocyte–osteoclast: all cycle back and forth depending on stimulus applied
- osteoclast> osteoblast= osteoporosis
4
Q
Osteoclast
A
- monocyte-derived, found in bone
- responsible for bone reabsorption
5
Q
Mast cells
A
- found in various connective tissues
- inflammatory mediators
6
Q
Adipose cells
A
- found in adipose tissues
- produce and store fat
- can be detrimental if too much development–> inflammation. Can pinch and cause pain; ex: fat pads in knees
7
Q
Mesenchyme cells
A
- undifferentiated cells primarily in embryos and in bone marrow
- can differentiate into any connective tissue cell
8
Q
Lymphocytes
A
-white blood cells that have a surface protein specific for antigens
9
Q
Neutrophils
A
-white blood cells involved in fighting infections
10
Q
Macrophages
A
- derived from monocytes; move into specific tissues
- involved in immune response
11
Q
Plasma cells
A
-B lymphocytes producing antibodies
12
Q
Aggrecan
A
- Proteoglycans
- found in numerous chains of Keratan sulfate and chondroitin sulfate
- binds to hyaluronan
- creates osmotic swelling pressures in cartilage by attracting water
13
Q
Chondroitin Sulfate
A
- Localization: cartilage, bone, heart valves, tendons, ligaments
- most abundant GAG, increases with compression
14
Q
Keratan Sulfate
A
- Localization: cornea, bone, cartilage
- forms part of large PG aggregates in cartilage
15
Q
Hyaluronan
A
- Localization: synovial fluid, vitreous humor, loose CT, healing CT, cartilage
- forms large PG aggregates
16
Q
Heparan Sulfate
A
- Localization: basement membranes, cell surfaces
- interacts with numerous proteins
17
Q
Dermatan Sulfate
A
- Localization: skin, blood vessels, tendons, ligaments
- increases with tensile stress
18
Q
Fibrillar collagen type I
A
- tensile strength
- tendons, bones, ligaments, skin, annulus fibrosis, menisci, fibrocartilage, joint capsules, cornea
- accounts for 90% of body collagen
19
Q
Fibrillar collagen type II
A
- hyaline articular cartilage, nucleus pulposis, vitreous humor
- weight bearing, water within, cartilage
20
Q
Fibrillar collagen type III
A
- skin, blood vessels, tendons, ligaments
- healing type of tissues
- make up endotendon which encloses groups of fibers along with the nerves, lymph vessels, and blood vessels
21
Q
Composition of bone
A
- water content: 25%
- 25-30% collagen- mainly type I
- mainly chondroitin sulfate
22
Q
Composition of cartilage
A
- water content: 60-85%
- 10-30% collagen, more than 90%= type II
- 8-10% aggregating PGs
23
Q
Composition of tendon
A
- water content: 60-75%
- 80% collagen: 95%= type I, less than 5%= type III
24
Q
Composition of ligament
A
- water content: 70%
- 75% collagen, 90%= type I, 10%= type III
- dermatin sulfate- resist tensile forces
- large amount of extracellular matrix, small amounts of PG (dry weight)
25
Type I Joint Receptors: Ruffini
- stretch-- usually at extremes of extension
| - fibrous layer of joint capsules on flexion side of joints, periosteum, ligaments, and tendons
26
Type II Joint Receptors: Pacini or Pacini-form
- compression or changes in hydrostatic pressure and joint movement
- located throughout joint capsule, particularly in deep layers and in fat pads
27
Type III Joint Receptors: Golgi, Golgi-Mazzoni
- pressure and forceful joint motion into extremes of motion
| - inner layer (synovium) of joint capsules, ligaments, and tendons
28
Type IV Joint Receptors: unmylelinated free nerve endings
- non-noxious and noxious mechanical stress or biomechanical stress
- located around blood vessels in synovial layer of capsule and in adjacent fat pads and collateral ligaments, tendons, periosteum
- nocioreceptors
29
Effects of load: tendon and ligament
- Decreased load: decreased collagen concentration, cross-linking, tensile strength
- Increased load: increased cross-sectional area, collagen concentration, cross-linking, tensile strength, stiffness
30
Effects of load: cartilage
- Decreased load: thinning of cartilage, advancing of subchondral bone, decreased PG synthesis, fewer PG aggregates
- Increased load: increases PG synthesis, increased volume
31
Effects of load: bone
- Decreased load: decreased collagen synthesis, bone formation, increased bone reabsorption
- Increased load: denser bone, increased synthesis of collagen and bone
32
Structure of a typical Diarthodial (synovial) joint
1. JOINT CAPSULE that is composed of two layers
2. JOINT CAVITY that is enclosed by capsule
3. SYNOVIAL TISSUE that lines the inner surface of capsule
4. SYNOVIAL FLUID that forms film over joint surfaces
5. HYALINE ARTICULAR CARTILage on surfaces on enclosed bones
also: intra/extra capsular ligaments, blood vessels, sensory nerves
33
Synarthroses Joints
1. FIBROUS:
- sutures (skull)
- gomphoses (teeth in maxilla/mandible)
- sydesmosis (tibia, fibula)
- synostoses (mature synchondrosis joints)
2. CARTILAGINOUS
- symphysis (IV, pubis bone)
- synchondrosis (hyaline cartilage connections-permits bone growth)
34
Effects of Immobilization on tendons and ligaments:
- decrease collagen content, decrease cross-linking between collagen fibers, decrease in the myotendon interdigitation structure
- overall size may remain the same
35
Things to do to minimize consequences of immobilization:
1. CPM (continuous passive motion) devices
2. decrease duration of casting periods
3. dynamic splinting devices to allow joint movement while preventing unwanted motion of healing structures
4. slowly grade loading after immobilization
5. extend recovery period from days/weeks -->months
36
Kinematic type of motions/displacements:
1. translatory/linear/gliding
2. rotary
3. curvilinear (combination of both)
37
Kinematic variables that describe motion:
1. TYPE of displacement (motion)
2. LOCATION of displacement in sapce
3. DIRECTION of displacement of the segment
4. MAGNITUDE of displacement
5. rate of change in displacement (velocity) or rate of change of velocity (acceleration)
38
Characteristics of Force and Gravity Vectors:
Force vectors: magnitude of force (length), direction, point of application
Gravity vectors: magnitude of force (proportional to mass of object), direction (perpendicular to ground, through COM, falls within BOS for stable object)
39
Newton's First Law
Law of Inertia: body remains at rest or in uniform motion until acted upon by an unbalanced or outside set of forces
40
Newton's Second Law
Law of acceleration: acceleration of an particle in proportional to the unbalanced force acting upon it and inversely proportional to the mass of the particle. a=F/m
41
Newton's Third Law
Law of Reaction: for every action, there is an equal and opposite reaction.
- action-reaction forces
- ex: gravity and contact forces
- can never be part of the same force system: cannot be added or offset each other because they are applied to different objects
42
Osteokinematics
movements of bones in space
- rotatory movements
- described my axis, plane, and direction
43
Arthrokinematics
movement of joint surfaces relative to one another. -Moving surface is described in relation to nonmoving surface. Ex: Convex joint surfaces generally roll and glide in opposite directions; concave joint surfaces generally roll and glide in the same direction
44
2 layers of the joint capsule:
1. stratum fibrosum (dense fibrous tissue, poor vascularization, rich innervation, type I collagen, attached to periosteum and reinforced by ligamentous and musculotendinous structures
2. stratus synovium (rich vascularization, poor innervation, synoviocytes synthesizes hyaluronate, serves as entry for cartilage and exit for waste)
45
Fibrillar type XI collagen
- regulates fibril size
| - found in cartilage
46
Fibrillar type IX collagen
- facilitates fibril interactions with PG molecules
| - found in cartilage
47
Chondronectin
glycoprotein that plays an important role in adhesion of chondoblasts to type II fibers in the presence of chondroitin sulfate
48
Zones of articular (hyaline) cartilage
Zone 1: outermost- type II collagen arranged parallel to surface- reduce friction
Zone 2: transitional stratum & Zone 3: radiate stratum: both form intermeshwork of type 2 collagen fibers- keeps PGs and water contained; can absorb compressive forces
Zone 3: collagen fibers start to run perpendicular and transition between uncalcified and calcified cartilage (tidemark)
49
hyaluronate
- reduces friction between joint surfaces and folds of the capsule
- responsible for viscosity and essential for lubrication
50
lubricin
glycoprotein- responsible for cartilage on cartilage lubrication, ability to dissipate energy
51
thixotropic
- synovial fluid
- when bony components of a joint are moving rapidly, viscosity of fluid decreases and provides less resistance to motion (speed and heat concept of movement and viscosity)
52
Young's modulus
-measure of a material's stiffness (resistance to external loads)
=change of stress/change of strain
