Connective Tissue Flashcards
What are the three major groups of CT?
embryonic, adult, and special
What are the categories of adult fibrous CT?
Loose, Dense regular and Dense irregular
What are the six functions of connective tissue?
structural framework
protection
supports and interconnects other tissues (binding tissue)
energy storage (adipose)
transports fluids, cells and dissolved chemicals
throughout the body
defense against invasion by microorganisms
What are the 6 cell types of connective tissue?
Fibroblasts
Mesenchymal Cells
Adipocytes
Chondrocytes
Osteoblasts
Hematopoietic Stem Cells
What are fibroblasts?
cells in CT that produce collagen, proteoglycans, and glycoproteins
What are mesenchymal cells?
Connective tissue stem cells (multipotent)
What are adipocytes?
cells in CT that store and release fats (remove lipids from blood, stores it and releases it into the bloodstream when needed)
What are chondrocytes?
cells in CT that produce and maintain cartilage components
What do osteoblasts do?
produce bone components
What do hematopoietic stem cells do?
produce red blood cells and immune cells (e.g., macrophages, mast cells, lymphocytes, plasma cells)
What are the three cell types found in ECM (fibrous)?
Collagen, Elastin, Reticular ribers
How does collagen affect the physical property of CT?
It resists tension. collagen fibrils are aligned and cross-linked to increase tensile strength
Which collagen type is the most common?
Type 1
How does Scurvy affect CT?
it weakens it; vitamin C deficiency; co-factor in cross-linking collagen fibers
How does Ehlers-Danlos affect CT?
Abnormal collagen synthesis leads to weak collagen fibers
How does Elastin affect the physical property of CT?
it allows for stretching; stretchable fiber. (assembly of tropoelastin, fibulin-1 and fibrillins 1/2)
What is Marfan’s syndrome?
an autosomal dominant disorder where elastin is weak (mutation in fibrillin-1 gene). patient’s tend to be tall with long arms/legs
What are the principle targets of Marfan’s syndrome?
ocular, skeletal and cardiovascular systems
How do Reticular fibers affect the physical property of CT?
they form the supportive meshwork
What is ground substance?
is an amorphous gel-like substance in the extracellular space that contains all components of the extracellular matrix except for fibrous materials such as collagen and elastin.
What are four things that make up the ground substance?
proteoglycans, hyaluronan, glycoproteins, extracellular proenzymes
What are three proteoglycans found in ground substance?
chondroitin sulfates, heparan sulfates, keratan sulfates
what are three glycoproteins found in ground substance?
cytokines, growth factors, structural proteins (fibronect, laminins, tenascins, link proteins)
What are three characteristics of embryonic connective tissue?
rich in ECM
rich in mesenchymal stem cells
some but not many collagen or reticular fibers
What are the 5 types of adult mesenchymal stem cells?
fibroblasts, muscle cells (skeletal and smooth), osteoblasts, chondroblasts and adipocytes
What are the three cell types in loose connective tissue?
areolar, adipose, reticular
What is areolar tissue?
low density tissue with both fixed and wandering cells; widespread
What is adipose tissue?
fat containing tissue?
What is reticular tissue?
tissue rich in reticular fibers; forms an open framework to create a supportive mesh for holding free cells
What are the three cell types of dense connective tissue?
Dense irregular connective tissue, dense regular connective tissue, and elastic connective tissue
What is dense irregular connective tissue?
fibers that are deposited in a random pattern (dermis of skin)
What is dense regular connective tissue?
fibers that are deposited in a highly regular pattern (tendons connecting skeletal muscle to bone)
What is elastic connective tissue?
tissue rich in elastin fibers
Which three cell types in loose areolar CT are fixed cells?
fibroblasts, adipocytes, and mesenchymal cells
Which four cell types in loose areolar CT are wandering cells?
macrophages, mast cells, leukocytes/lymphocytes, plasma cells
What are the three functions of loose connective tissue?
to support and bind other tissues; hold body fluids, defend against infection
what is lamina propria?
loose connective tissue that is found immediately beneath membraneous epithelia
What is adipose CT and what are the functions?
tissue that is characterized by abundant adipocytes and sparse ECM
it provides reserve energy source and insulates against heat loss, supports and protects organs, and it is found under skin, around organs, within abdomen, breasts and buttocks
What is white fat?
tissue that functions in energy storage, insulation, cushioning vital organs and hormone secretion
What is brown fat?
key thermogenic tissue, abundant in newborns, greatly reduced in adults
What is reticular connective tissue?
tissue rich in reticular fibers; form scaffolding for other cells
Where is reticular connective tissue found?
liver, bone marrow, lymph nodes and spleen where the meshwork houses blood cells and immune cells outside blood and lymphatic vessels
What is the principle cell type of dense irregular and regular connective tissue?
fibroblasts
where is dense irregular CT found in?
dermis of skin, capsules that surround internal organs, perichondrium and periosteum, fascia
where is dense regular CT found in?
tendons, ligaments, aponeuroses, dense fascia, joint capsules
Where is elastic CT found in and why?
blood vessel walls, bronchiole tubes, special ligaments; because they allow recoil of tissue following stretching
What do mast cells do?
secrete chemicals such as histamine that mediate the allergic response, and heparin, an anticoagulant of blood
What do plasma cells do?
produce antibodies that mediate immunity
