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

Answer later

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

Answer later

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Connective Tissue: Overview 1/5

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

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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

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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)

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Connective Tissue: Overview 4/5

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

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Connective Tissue: Overview 5/5

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

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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

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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

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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)

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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

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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)

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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)

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Fibers 1/3

Formed from proteins secreted by fibroblasts

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Fibers 2/3

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

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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

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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

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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

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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

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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

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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

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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

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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

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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.

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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)

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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

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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