4. Introduction To Microanatomy: Connective Tissue Flashcards Preview

FMS: Pathology > 4. Introduction To Microanatomy: Connective Tissue > Flashcards

Flashcards in 4. Introduction To Microanatomy: Connective Tissue Deck (27):

1. Identify and describe the main components of connective tissue (objective)

Answer later


2. Identify and describe the main types of connective tissue proper (objective)

Answer later


Connective Tissue: Overview 1/5

Provides a matrix that serves as structural support and physically connects tissues and cells together to form organs


Connective Tissue: Overview 2/5

Provides metabolic support to cells/serves as medium for diffusion of nutrients and waste products
-Important site for storage of water, electrolytes and lipids


Connective Tissue: Overview 3/5

Plays a role in defense against foreign objects (gel-like consistency of matrix provides physical barrier, also home to inflammatory and immune cells)


Connective Tissue: Overview 4/5

Helps regulate cell-cell signaling by binding signaling molecules (regulates growth and depth of tissues)


Connective Tissue: Overview 5/5

Differs from other tissue types in structure: composed mostly of extracellular material with relatively few cells


Cells of Connective Tissue: Mesenchymal Cells

Undifferentiated cells that produce all types of proper and specialized connective tissue and contain stem cells for other tissue (blood, muscle)

Give rise to fibroblasts and lipoblasts


Cells of Connective Tissue: Fibroblasts

-Most common cells in connective tissue proper
-Produce and maintain collagen and elastin to form fibers
-Synthesize and secrete components of ground substance


Cells of Connective Tissue: Lipoblasts

-Give rise to adipocytes (fat cells) specialized for cytoplasmic storage of lipid
-Tissue with large population of adipocytes also serve to cushion and insulate (skin, kidney)


Cells of Connective Tissue: Macrophages

-Specialize in removal of dead cells and tissue debris, bacteria and other foreign material
-Can activate immune system and promote inflammatory response
-Secrete enzymes to break down dead tissue and growth factors to promote repair and healing
Ex. Removing E. Coli bacteria


Cells of Connective Tissue:
Mast Cells

-Type of immune cell which stores chemical mediators important in localized immune response and tissue repair
-Often located near blood vessels, in tissue lining digestive and respiratory treat (areas where threats can be detected)


Extracellular Matrix

-Contains structural proteins (collagen and elastin fibers) embedded in viscous gel made up of protein-polysaccharide complexes (proteoglycans), water, and adhesive glycoproteins that bind to matrix proteins and cell membrane proteins (laminin, fibronectin)


Fibers 1/3

Formed from proteins secreted by fibroblasts


Fibers 2/3

3 main types: 2 types made of collagen (collagen, reticular) and 1 type made of elastin (elastic)


Fibers 3/3

Types of fibers distributed unequally among different types of connective tissue- predominate fiber type confers tissue properties
-Collagen/reticular: impart tensile strength (shearing), provide supporting framework
-Elastic: imparts elasticity and resilience, allows for deformation and recoil


Collagens 1/2

-30% of body (dry weight), most common protein type
-Family of proteins which are extremely strong and resistant to shearing/tearing forces


Collagens 2/2

Categorized by formed structures:
-Fibrillar: Type I most abundant and widely distributed, forms collagen fibers of ECM), Type III forms reticular fibers
-Network/sheet-forming: Type IV major structural proteins of basement membranes
-Linking/anchoring: Type VII anchors layers of basement membrane to each other


Collagen Fibers

Abundant in dermis, organ capsules, tendons and ligaments

Largest, thick pink bands on A&E, collagen, wavy and do not branch (run in bundles), strength, tendon/ligament


Reticular Fibers

Forms delicate network of thin fibers that provide supportive stroma for bone marrow, lymph nodes, organs including liver and spleen
Can't see on A&E, need Silver Stain

Smallest, reticulin, not wavy and branch/intersect, support, spleen/lymph nodes/bone marrow/inside organs


Elastic Fibers

Form sparse networks interspersed with collagen bundles in tissue subject to stretching or bending (skin, vertebral ligaments, elastic arteries, vocal cords)
Elastic: medium, thinner pink bands on A&E, elastin, less wavy and branch (run singly), elasticity, lungs/aorta/blood vessels


Connective Tissue: Classification

By ratio of components
-Loose: composed of cells, fiber, ground substance in equal amounts (if see ground substance in between clue)
-Dense: densely packed collagen fibers with fewer cells
---Regular: fibers aligned in parallel
---Irregular: fibers randomly interwoven


Connective Tissue Proper: Loose (areolar)

Description: gel-like matrix with all three fiber types; cells: fibroblasts/macrophages/mast cells/some wbc's
Function: cushion organs, phagocytize bacteria, inflammation, hold/conveys tissue fluid
Location: widely under epithelia, makes up LAMINA PROPRIA


Connective Tissue Proper: Loose (adipose)

Description: matrix like areolar but very sparse; closely packed fat cells, have nuclei pushed to side of large fat droplets
Function: reserve food fuel; insulates against heat loss; supports/protects organs
Location: under skin; around kidneys and eyeballs; within abdomen; in breasts.


Connective Tissue Proper: Loose (reticular)

Description: network of reticular fibers in typical loose ground substance, reticular cells lie on network
Function: fibers form soft internal skeleton (stroma) that supports other cell types (including wbc's, mast cells, macrophages)
Location: lymphoid organs (lymph nodes, bone marrow, spleen)


Connective Tissue Proper: Dense (dense regular)

Description: primarily parallel collagen fibers; few elastin fibers; major cell type is fibroblast
Function: attaches muscles to bones or to muscles; attach bones to bones; withstand tensile stress when pulling force is applied one direction
Location: tendons/ligaments/aponeuroses


Connective Tissue Proper: Dense (dense irregular)

Description: primarily irregularly arranged collagen fibers; some elastic fibers; fibroblasts is major cell type
Function: withstand tension exerted in many directions; structural strength
Locations: fibrous capsules of organs and of joints; dermis of the skin; submucosa of digestive tract