What is connective tissue proper?
Soft tissues; components in a fluid or gelatinous ground substance
What are examples of soft connective tissues?
Adipose
Blood
What are supportive connective tissues?
Hard tissues: components embedded in a solid ground substance
What are some examples of supportive connective tissues?
Bone
Cartilage
Classification of connective tissue is based on what two things?
Relative density of components
Characteristics of the extracellular matrix
What makes up extracellular matrix?
Ground substance + fibers
What are the 3 components of connective tissues?
Fibers
Ground substance
Cells
What are the 3 types of fibers found in connective tissue?
Collagen fibers
Elastic fibers
Reticular fibers
What do subtypes of connective tissue depend on?
Types and arrangements of fibers
What percent of total body protein is collagen fiber?
30-40%
Are collagen fibers capable of stretching or contracting?
No
Which type of fibers are heat labile?
Collagen fibers
What does heat labile mean?
With heat, collagen fibers become gelatinous and glue-like
Do collagen fibers have a high or low molecular weight?
High
Collagen fibers are composed primarily of which three amino acids?
Glycine
Proline
Hydroxyproline
What is the most abundant amino acid in collagen fibers?
Glycine
What is the monomer of collagen fiber called?
Tropocollagen
Are collagen fibers straight or wavy?
May be either
What determines whether collagen fibers are loosely or densely packed?
Location and function requirements
What is the most common type of collagen?
Type I
What is type II collagen?
Makes cartilage
Where is type III collagen found?
Smooth muscle Aorta Uterus Spleen Lungs
Where is type IV collagen found?
Basal lamina
In the basal lamina, what is the specific location where type IV collagen is found?
Between epithelial and connective tissues
Where is type V collagen found?
Placental membranes
What are the 2 main features of elastic fibers?
Stretch
Resistant to heat
In elastic fibers, what surrounds the elastin?
Microfibrils
Elastin proteins are rich in which amino acids?
Glycine
Proline
Also contains: Valine, desmosine and isodesmosine
Reticular fibers are usually found where ___ is found.
Collagen
Where is reticular fiber abundant?
Boundaries between connective tissue and other tissues
What fibers make up the majority of the stroma in bone marrow?
Reticular fibers
Besides bone marrow, what are 2 places where there are many reticular fibers?
Lymphoid tissues
Liver
Which type of fibers blacken with silver stains?
Reticular fibers
Do reticular fibers form bundles?
Nope
What type of collagen fibrils make up reticular fibers?
Type III (no bundles, thought)
What is the connective tissue ground substance made of?
Mixture of : Proteins Lipid Carbs Water
What is the consistency of ground substance?
Can be ciscous to solid
What are the 2 main protein components of ground substance?
Glycoproteins
GAGs
GAGs have many ___ groups.
Hydrophilic
GAGs may serve as a protective barrier to the diffusion of what?
Inorganic ions
Charged molecules
What are 3 examples of GAGs in connective tissue?
Hyaluronic acid
Chondroitin sulfate
Dermatan sulfate
Viscosity of ground substance is related to what?
Types of GAGs present
Is hyaluronic acid sulfated or non-sulfated?
Non-sulfated
Hyaluronic acid can bind large amounts of what?
Water
Where is chondroitin sulfate present?
Hard connective tissues
What are the 4 loose connective tissue subtypes?
Areolar
Adipose
Reticular
Hemopoietic
What is the function of areolar connective tissue?
To bind organs together
What is the structure of areolar connective tissue?
Loosely arranged collagen
What is the function of adipose tissue?
Fat storage
What type of cell predominates in adipose connective tissue?
Adipocytes
What are the 5 types of cells of loose connective tissue?
- Fibroblasts
- Mesenchymal cells
- Adipocytes
- Macrophages
- Mast cells
What shape are fibroblasts?
Fusiform or stellate
How many nucleoli are found in fibroblasts?
1-2
Fibroblasts arise from what cells?
Other fibroblasts
Mesenchymal cells
What is the most common cell in loose connective tissue?
Fibroblast
What is the function of the fibroblast?
Produces fibers and ground substance
Important in wound healing
What is the nucleus of fibroblasts made of?
Fine chromatin
What is the nucleus of mesenchymal cells made of?
Coarse chromatin
Mesenchymal cells are similar to what kind of cells?
Fibroblasts
What is the function of mesenchymal cells?
To give rise to other mesenchymal derived cells (they are stem cells)
What are adipocytes specialized for?
Synthesis and/or intake of lipids
The cytoplasm and nucleus are displaced in which direction in adipocytes?
Laterally
What do macrophages originate from?
Blood monocytes
Is the outline of macrophages irregular or regular
Irregular
What shape is a macrophage nucleus?
Ovoid
What is the function of macrophages
Phagocytosis of cell debris, microorganisms and foreign material
To “process” antigens
The cytoplasm of mast cells is full of what?
Secretory granules
Mast cells are usually associated with what?
Capillaries
Which type of cell has a small, dark-staining nucleus?
Mast cells
What is the function of the mast cells?
Contain heparin and histamine
What does heparin do?
Anticoagulant
What does histamine do?
Dilates blood vessels
What are the 2 types of agranulocyte cells in connective tissue?
- Lymphocytes
2. Plasma cells
What are the smallest cells in the connective tissue with large, dark staining nuclei?
Lymphocytes
