Connective Tissue Flashcards
Extracellular Matrix components
Ground substance and protein fibers (elastic fiber, collagen fiber, and reticular fiber)
Types of Connective tissue proper
Loose (areolar) connective tissue, Dense irregular connective tissue, Dense regular connective tissue
Types of Embryonic connective tissues
Mesenchyme and Mucoid (mucous) connective tissue
Types of specialized connective tissues
Reticular connective tissue, Adipose tissue, Cartilage, Bone, Blood
Loose (areolar) connective tissue organization
A type of connective tissue proper with more ground substance than collagen; randomly distributed
Loose (areolar) connective tissue function
Function: Supports microvasculature, nerves, and immune defense
Example: Lamina propria beneath epithelial lining of digestive tract
Dense irregular connective tissue organization
A type of connective tissue proper with little ground substance; few cells (mostly fibroblasts); much collagen in randomly arranged fibers, some elastic fibers
Dense irregular connective tissue function
Function: Protects and supports organs; resists tearing
Example: Dermis of skin, organ capsules, submucosa layer of digestive tract
Dense regular connective tissue organization
A type of connective tissue proper that is almost completely filled with parallel bundles of collagen; few fibroblasts, aligned with collagen
Dense regular connective tissue function
Function: Provide strong connections within musculoskeletal system, strong resistance to force
Example: Ligaments, tendons, aponeuroses, corneal stroma
Mesenchyme organization
A type of embryonic connective tissue that has sparse, undifferentiated cells, uniformly distributed in matrix with sparse collagen fibers
Consists largely of viscous ground substance with few collagen fibers
Mesenchyme function
Function: Contains stem/progenitor cells for all adult connective tissue cells
Example: Mesodermal layer of early embryo
Mucoid (mucous) connective tissue organization
A type of embryonic connective tissue with random fibroblasts and collagen fibers in viscous matrix
Mucoid (mucous) connective tissue function
Function: Supports and cushions large blood vessels
Example: Matrix of the fetal umbilical cord
Reticular connective tissue organization
A type of specialized connective tissue that has a delicate network of reticulin/collagen III with attached fibroblasts (reticular cells)
Reticular connective tissue function
Function: Supports blood-forming cells, many secretory cells, and lymphocytes in most lymphoid organs
Example: Bone marrow, liver, pancreas, adrenal glands, all lymphoid organs except the thymus
Glycosaminoglycan (GAG, also called mucopolysaccharide)
A complex polysaccharide composed of disaccharide groups (a “double-sugar”). GAG’s are highly polar and attract water
Two common examples of glycosaminoglycans are
chondroitin sulfate and
heparin.
The largest most ubiquitous GAG is hyaluronan (hyaluronic acid) which is important in diffusion through connective tissue and in lubricating various organs and joints.
Chondroitin Sulfate
A common GAG used as a supplement for joint health.
Functions in space filling, cushioning, and lubrication. Found in cartilage
Collagen fibers
The most important and abundant connective tissue fibers; a protein, with some 20 related types. One of the protein fibers associated with ECM
Collagen is produced by fibroblasts
Collagen forms about 30% of body weight
Reticular fibers
Delicate network of Type III collagen, found in reticular tissue, stain very dark with silver stains and are abundant in immune and lymphoid tissues. One of the protein fibers associated with ECM
Elastic fibers
Sheets called elastic lamellae, are composed of elastin and fibrillin in a stretchable conformation. One of the protein fibers associated with ECM
Type I Collagen
Location: Skin, tendon, bone, dentin
Function: Resistance to tension
Type II Collagen
Location: Cartilage, vitreous body
Function: Resistance to pressure
Cells of Connective Tissues
Fibroblasts, Adipocytes
Originate form hematopoietic stem cells in bone marrow: Macrophages, Mast cells, Plasma cells, other leukocytes (WBCs)
Fibroblasts (fibrocytes)
Major Product or Activity: Extracellular fibers and ground substance
Synthesize and secrete most components of the ECM, including fibers (collagen and elastin)
Key cells in connective tissue proper
Plasma cells
Major Product: Antibodies
Originate from hematopoietic stem cells in bone marrow, circulate in the blood, and then move into connective tissue where they function.
Macrophages
Major Product or Activity: Phagocytosis of ECM components and debris; antigen processing and presentation to immune cells; secretion of growth factors, cytokines, and other agents
Originate from hematopoietic stem cells in bone marrow, circulate in the blood, and then move into connective tissue where they function.
Mast cells and basophilic leukocytes
Major Products or Activity: A type of white blood cell (leucocyte) and are part of the immune system. Mast cells release vasoactive agents and other substances during inflammatory and allergic reactions, and tissue repair.
Pharmacologically active molecules (eg. histamine).
They originate
from blood cell precursors in bone marrow.
Adipocytes
Major Activity: Storage of neutral fats
Ground substance
Comprised of Glycosaminoglycans (GAGs) or mucopolysaccharides, Proteoglycans, and other multi-adhesive glycoproteins
Importance in water balance, especially in capillaries and surrounding tissues
Interstitial fluid
Water in the ground substance of connective tissue
Keloid
a local swelling caused by abnormally large amounts of collagen that form in scars of the skin
Primarily form in people of African descent
Skin repair process
Repair occurs in overlapping stages
- Blood clots at wound site, releasing growth factors and other substances.
- Macrophages and neutrophils enter the wound as inflammation begins, and epithelial cells from the cut edges of the epidermis begin to migrate beneath and through the blood clot.
- Under the influence of growth factors and hydrolytic enzymes released in part from macrophages, fibroblasts proliferate and produce new collagen to form “granulation tissue” containing new, growing capillaries.
- The epidermis gradually re-establishes continuity over the wound, but excessive collagen usually remains in the dermis as scar tissue.
Aponeuroses are composed of which type of connective tissue proper?
Dense regular connective tissue
One type of GAG is chondroitin sulfate, which functions in space-filling, cushioning, and lubrication. One tissue where this molecule is found is
Cartilage
What do these cell types have in common: Microglia, osteoclasts, and Kupffer cells?
They are part of the mononuclear phagocyte system.
What is the most abundant protein in the human body?
Collagen
The formation of scar tissue following surgery or wounding is largely due to
Fibroblasts
One major function of connective tissue proper is to physically support and connect other tissues. A second major function is to
Maintain water as interstitial fluid for nutrient and metabolite diffusion, using hydrostatic and osmotic pressure.
The dermis of the skin contains which type of connective tissue proper?
Dense irregular connective tissue
What is the function of mucoid connective tissue?
Protection of blood vessels in the umbilical cord.
The major component, in terms of volume, of connective tissue is
Extracellular Matrix (ECM)
What are the two main components of extracellular matrix?
Ground Substance and Protein Fibers
Antibodies are glycoproteins of the immunoglobulin family that interact with specific antigens. Which type of cells produce antibodies?
Plasma cells
Edema
The excessive accumulation of interstitial fluid in connective tissues
What cell type triggers allergic reactions by secretion of several types of substances?
Mast Cells
Edema is the excessive accumulation of interstitial fluid in connective tissue. Where does this fluid come from before it accumulates in the connective tissue?
Blood passing through the capillary walls that become more permeable during inflammation
Connective tissue forms the ________________of many organs.
Stroma
Elastic fibers are formed from two proteins:
Fibrillin and elastin
Which type of fibers are tendons composed of?
Collagen
Scar tissue is composed of what type of fibers?
Collagen
Fibroblasts are an important cell type in connective tissue. They synthesize collagen and elastin, as well as the three major macromolecules in ground substance. How do fibroblasts differ from macrophages and mast cells?
Fibroblasts originate from mesenchymal cells, whereas the others originate from stem cells in bone marrow.
Proteoglycans
A core protein with a variety of sulfated GAGs attached to it. A type of macromolecule in ground substance
Multi-adhesive glycoproteins
Small glycosylated proteins with many binding sites for other molecules. A type of macromolecule in ground substance.
How is immediate hypersensitivity (Type I hypersensitivity) reaction different from the normal infectious immune response of mast cells?
The immediate hypersensitivity reaction typically requires a previous sensitization to the allergen.
Reticular fibers are made of type III collagen. They function as a supportive stroma in which organs/glands?
Lymphoid organs, Endocrine glands, Hematopoietic organs
From which major embryonic tissue is mesenchyme derived?
Mesoderm
The two major types of protein fibers in the ECM are
Collagen and elastic
Reversed prompt
Ground substance and protein fibers (elastic fiber, collagen fiber, and reticular fiber)
Extracellular Matrix components
Reversed prompt
Loose (areolar) connective tissue, Dense irregular connective tissue, Dense regular connective tissue
Types of Connective tissue proper
Reversed prompt
Mesenchyme and Mucoid (mucous) connective tissue
Types of Embryonic connective tissues
Reversed prompt
Reticular connective tissue, Adipose tissue, Cartilage, Bone, Blood
Types of specialized connective tissues
Reversed prompt
A type of connective tissue proper with more ground substance than collagen; randomly distributed
Loose (areolar) connective tissue organization
Reversed prompt
Function: Supports microvasculature, nerves, and immune defense
Example: Lamina propria beneath epithelial lining of digestive tract
Loose (areolar) connective tissue function
Reversed prompt
A type of connective tissue proper with little ground substance; few cells (mostly fibroblasts); much collagen in randomly arranged fibers, some elastic fibers
Dense irregular connective tissue organization
Reversed prompt
Function: Protects and supports organs; resists tearing
Example: Dermis of skin, organ capsules, submucosa layer of digestive tract
Dense irregular connective tissue function
Reversed prompt
A type of connective tissue proper that is almost completely filled with parallel bundles of collagen; few fibroblasts, aligned with collagen
Dense regular connective tissue organization
Reversed prompt
Function: Provide strong connections within musculoskeletal system, strong resistance to force
Example: Ligaments, tendons, aponeuroses, corneal stroma
Dense regular connective tissue function
Reversed prompt
A type of embryonic connective tissue that has sparse, undifferentiated cells, uniformly distributed in matrix with sparse collagen fibers
Consists largely of viscous ground substance with few collagen fibers
Mesenchyme organization
Reversed prompt
Function: Contains stem/progenitor cells for all adult connective tissue cells
Example: Mesodermal layer of early embryo
Mesenchyme function
Reversed prompt
A type of embryonic connective tissue with random fibroblasts and collagen fibers in viscous matrix
Mucoid (mucous) connective tissue organization
Reversed prompt
Function: Supports and cushions large blood vessels
Example: Matrix of the fetal umbilical cord
Mucoid (mucous) connective tissue function
Reversed prompt
A type of specialized connective tissue that has a delicate network of reticulin/collagen III with attached fibroblasts (reticular cells)
Reticular connective tissue organization
Reversed prompt
Function: Supports blood-forming cells, many secretory cells, and lymphocytes in most lymphoid organs
Example: Bone marrow, liver, pancreas, adrenal glands, all lymphoid organs except the thymus
Reticular connective tissue function
Reversed prompt
A complex polysaccharide composed of disaccharide groups (a “double-sugar”). GAG’s are highly polar and attract water
Two common examples of glycosaminoglycans are
chondroitin sulfate and
heparin.
The largest most ubiquitous GAG is hyaluronan (hyaluronic acid) which is important in diffusion through connective tissue and in lubricating various organs and joints.
Glycosaminoglycan (GAG, also called mucopolysaccharide)
Reversed prompt
A common GAG used as a supplement for joint health.
Functions in space filling, cushioning, and lubrication. Found in cartilage
Chondroitin Sulfate
Reversed prompt
The most important and abundant connective tissue fibers; a protein, with some 20 related types. One of the protein fibers associated with ECM
Collagen is produced by fibroblasts
Collagen forms about 30% of body weight
Collagen fibers
Reversed prompt
Delicate network of Type III collagen, found in reticular tissue, stain very dark with silver stains and are abundant in immune and lymphoid tissues. One of the protein fibers associated with ECM
Reticular fibers
Reversed prompt
Sheets called elastic lamellae, are composed of elastin and fibrillin in a stretchable conformation. One of the protein fibers associated with ECM
Elastic fibers
Reversed prompt
Location: Skin, tendon, bone, dentin
Function: Resistance to tension
Type I Collagen
Reversed prompt
Location: Cartilage, vitreous body
Function: Resistance to pressure
Type II Collagen
Reversed prompt
Fibroblasts, Adipocytes
Originate form hematopoietic stem cells in bone marrow: Macrophages, Mast cells, Plasma cells, other leukocytes (WBCs)
Cells of Connective Tissues
Reversed prompt
Major Product or Activity: Extracellular fibers and ground substance
Synthesize and secrete most components of the ECM, including fibers (collagen and elastin)
Key cells in connective tissue proper
Fibroblasts (fibrocytes)
Reversed prompt
Major Product: Antibodies
Originate from hematopoietic stem cells in bone marrow, circulate in the blood, and then move into connective tissue where they function.
Plasma cells
Reversed prompt
Major Product or Activity: Phagocytosis of ECM components and debris; antigen processing and presentation to immune cells; secretion of growth factors, cytokines, and other agents
Originate from hematopoietic stem cells in bone marrow, circulate in the blood, and then move into connective tissue where they function.
Macrophages
Reversed prompt
Major Products or Activity: A type of white blood cell (leucocyte) and are part of the immune system. Mast cells release vasoactive agents and other substances during inflammatory and allergic reactions, and tissue repair.
Pharmacologically active molecules (eg. histamine).
They originate
from blood cell precursors in bone marrow.
Mast cells and basophilic leukocytes
Reversed prompt
Major Activity: Storage of neutral fats
Adipocytes
Reversed prompt
Comprised of Glycosaminoglycans (GAGs) or mucopolysaccharides, Proteoglycans, and other multi-adhesive glycoproteins
Importance in water balance, especially in capillaries and surrounding tissues
Ground substance
Reversed prompt
Water in the ground substance of connective tissue
Interstitial fluid
Reversed prompt
a local swelling caused by abnormally large amounts of collagen that form in scars of the skin
Primarily form in people of African descent
Keloid
Reversed prompt
The excessive accumulation of interstitial fluid in connective tissues
Edema
Reversed prompt
A core protein with a variety of sulfated GAGs attached to it. A type of macromolecule in ground substance
Proteoglycans
Reversed prompt
Small glycosylated proteins with many binding sites for other molecules. A type of macromolecule in ground substance.
Multi-adhesive glycoproteins