Fundamentals Exam 1 Flashcards
Major CT in body includes…
Tendons, ligaments, cartilage, bone, muscle
What are the major components of CT?
(1) FIBERS: Collagen and elastin
(2) Ground substance with associated fluid
(3) Cellular substances: fibroblast, cells specific to each CT type
What is ground substance?
Non collaginous components of the extracellular matrix Ground substance is important in overall tensile strength of the tissue
Fibroblasts are called ___ in bone and ___ in artilage
Fibroblasts = osteoblasts in bone, chondrocytes in cartilage
Describe Type I collagen
Type I: Resistance to tension (tensile strength), found in ligaments, bone, dermis, fibrous cartilage, epimysium, perimysium, endomysium, fascia, joint capsule, meniscus, and mature scars
Describe Type III collagen
Type III: Structured maintenance for organs - loosely packed, thin fibrils such as smooth muscle in CV and GI systems
Describe Type IV collagen
Type IV: Support and filtration. Thin amorphous such as basement membrane
Describe Type II Collagen
Type II: Resistance to intermittent pressure; loosely packed, no fibers, very thin fibrils such as hyaline and elastic cartilage, menisci
____ molecules combine to form collagen ___, which is the smallest unit visible on electron microscope. These then combine to form collagen ____.
TROPOCOLLAGEN molecules combine –> collagen FIBRILS –> collagen FIBERS
Describe collagen arrangement in tendons, ligaments, and joint capsule.
Tendon: closely packed, roughly parallel
Ligament: not as parallel as tendon, but more organized than a capsule
Joint capsule: loose weave of interlaced fibers
Collagen aligns purposefully according to ____. [Early/late] movement allows for better alignment and motion of collagen.
Collagen aligns purposefully according to THE DIRECTION OF FORCE OR STRESS. If no activity and no stress is put on collagen, it does not align well and aligns in a disorganized fashion. EARLY movement –> better alignment
Functions of CT
Support (the tissue itself and underlying tissue)
Strength
Repair
Mechanical connector between cells and other structures
Connective tissue provides ___ strength. What does this mean?
CT provides TENSILE strength = amount of stress a tissue can take before it will fail. This is different in different tissues and depends on the organization of collagen, intermolecular bonds, and ground substance
CT is weaker vs. stronger at what part of the tissue?
Weaker at tissue intersurface, strongest in the middle
CT vascularity is generally [good/poor]. What’s the exception?
Vascularity of CT is POOR with the exception of BONE
Neural innervations to CT are [lacking/abundant]. What’s an example? What’s the exception?
Neural innervations in CT are ABUNDANT! E.g. muscle spindle, GTO. Exception: cartilage is not highly innervated
Describe elastin’s role in CT.
Elastin provides elastic properties by their unique cross linking. Allows for stretch and return to resting level. Gives degree of flexibility to CT
Inflammatory Phase... # days? Is it good or bad? Cardinal signs?
INFLAMMATORY PHASE
- 1-6 days
- Good thing! It’s protective and kicks off healing process
- Redness, swelling, pain, loss of function, heat
Inflammatory phase has 4 main parts. Describe each, the goal of each, and duration.
(1) Vasoconstriction: decrease blood loss to area. Short duration
(2) Vasodilation: increase capillary permeability. Lasts up to an hour
(3) Clot formation: platelets are first cells at site of injury. Plts bind to exposed collagen and release fibrin to stimulate clotting and prevent further blood loss.
(4) Phagocytosis: monocytes convert to macrophages when they migrate from capillaries to tissues in wound. Macrophages considered MOST important role in inflammatory phase. Macrophages produce an enzyme called collagenase which removes some of necrotic tissue
Systemic effects of inflammatory phase may include…
Fever, increased WBC count, Tachycardia, increased overall metabolic rate
List the 3 phases of healing.
Inflammatory phase, proliferation phase, maturation phase
List the 4 processes that take place during the Proliferation Phase. What’s the goal of this phase?
GOAL: Achieve coalescence and closure of injured area
- Epithelialization
- Collagen production
- Wound Contraction
- Neovascularization
Epithelialization:
When does it begin? How long?
Purpose?
What happens?
- Begins within a few hours of injury (deeper wounds may take longer to initiate)
- Wound can be clinically resurfaced in 48 hrs
- Purpose: produce a barrier to prevent fluid loss & keep contaminants out
- How? Epithelial cells are normally in contact with each other. When interrupted, they begin to migrate and eventually form a barrier across the wound
Collagen Production. Describe how we get from fibroblasts to collagen fibers.
Fibroblasts generate procollagen which converts into TROPOCOLLAGEN which makes up COLLAGEN FIBRILS which make up COLLAGEN FILAMENTS which make up COLLAGEN FIBERS