What are the properties of Connective Tissue?
What cells are considered Connective Tissue?
Properties: Separated by outside environment via epithelium and from other CT cells via ECM
1. Fibroblasts: collagen, proteoglycans, glycoproteins
2. Mesenchymal: CT stem cells
3. Adipocytes: fat cells
4. Chondrocytes: cartilage
5. Osteoblasts: bone
6. Hematopoietic: RBC and Immune Cells
What are the functions of Connective Tissue?
1. Structural framework
2. Protection and support
3. Energy storage
4. Transport fluids, cells, and dissolved chemicals
5. Immune System Defense
What organelles might a plasma cell have a disporportionate volume of?
Golgi Apparatus/Rough Endoplasmic Reticulum
(It produces and exports antibodies)
What are the fibrous components of the ECM of connective tissue?
1. Collagen: Resists tension
2. Elastin: Stretchable Fiber
3. Reticular Fibers: supportive meshwork
Besides the structural, what is the function of Extracellular Matrix?
Carries O2, CO2, Nutrients, and Wastes
What is the most common type of collagen?
What is Elastin assembled from?
Fibrillins 1 and 2
What can cause shallow breathing in COPD relating to connective tissue?
Elastin breakdown prevents the lungs from retracting fully to prepare for the next inhalation.
What makes the Extracellular Matrix in bone different from that in other tissues?
It is mineralized
What composes the ECM ground substance?
1. Proteoglycans (protein w/ sugar)
Ex: Chondroitin, Heparan, Keratan Sulfates
2. Hyaluronan: connects proteoglycans
Includes cytokines, GF, structural proteins
4. Extracellular proenzymes
What are Syndecans?
Strong coreceptors for growth factors on the cell membrane
What do integrin receptors do as a basic function?
Allow cell to extracellular matrix interaction
What is the name of umbillical embryonic connective tissue?
What are the three types of loose connective tissue?
What is the lamina propria?
Loose connective tissue beneath membranous epithelia
What are the fixed cells of areolar connective tissue?
What are the wandering cells of loose areolar connective tissue?
Leukocytes / Lymphocytes
Where can you find adipocytes?
Under skin and organs (e.g. kidneys, eyeballs)
Within abdomen, breats, and buttocks
What are the 4 functions of white fat?
Energy storage, insulation, cushioning, hormone secretion
What are the characteristics of brown fat?
Abundant in newborns
Greatly reduced in adults
Contains abundant mitochondria
What does reticular connective tissue do?
Forms a "chicken wire" cage to support and hold cells in place against gravity
What are the three types of dense connective tissue?
Where is dense irregular connective tissue found?
Dermis of the skin
Capsules of internal organs (eg kidney)
Perichondrium and pariosteum
Why might dense regular connective tissue heal slowly compared to other tissues?
It is poorly vascularized
Where can you find dense connective tissue?
What is the principal cell type of dense connective tissue?
Where might elastic connective tissue be found and what does it do?
Elastic CT: allows for recoil of tissue follwing streching
Location: Walls of large arteries
Walls of bronchiole tubes (lungs can expand collapse)
Special ligaments (eg Ligamentum Nuchae)
What is Ehlers-Danlos Syndrome?
A mutation in collagen synthesis and structure, leading to weak collagen fibers.
What does a deficiency of Vitamin C cause in connective tissue?
What is the basic mechanism?
Weakens Connective Tissue
Vitamin C is necessary for cross linking of collagen fibers
-Deficiency leads to less cross-linked collagen
What is mutated in Marfan's Syndrome?
Which organs are affected?
Autosomal disorder: Fibrilin-1 is mutated (weak elastin)
-affects ocular, skeletal, and cardiovascular systems