Connective Tissue Histology Flashcards
What are the two major groups of CT?
Embryonic (contains pluripotent stem cells)
Adult
These cells produce collagens, proteoglycans, and glycoproteins.
Fibroblasts
Theses cells are CT stem cells.
Mesenchymal cells
These cells store and release fats.
Adipocytes
These cells produce and maintain cartilage components.
Chondrocytes
These cells produce bone components.
Osteoblasts
These cells produce RBCs and immune cells (i.e., macrophages, mast cells, lymphocytes, plasma cells).
Hematopoietic stem cells
Collagens (several different types, type-I most common) – resists ________.
Tension
This is a stretchable fiber.
Elastin
These fibers form a supportive meshwork.
Reticular fibers
This type of collagen fibers are aligned and cross linked to increase tensile strength. In electron micrographs, banding of collagen fibers is observed due to fibril alignment.
Type-I collagen
This is due to a vitamin C deficiency, which is a co-factor in cross-linking collagen fibers. This weakens the CT.
Scurvy
This disease is due to an abnormal collagen synthesis leading to weak collagen fibers (multiple forms).
Ehlers-Danlos Syndrome
In the ECM of CT there is amorphous ground substances. These include…
Proteoglycans
Hyaluronan
Glycoproteins
Extracellular proenzymes
What proteoglycans are part of the amorphous ground substance?
Chondroitin sulfates
Heparan sulfates
Keratan sulfates
What glycoproteins are part of the amorphous ground substance?
Cytokines
Growth Factors
Structure Proteins (i.e., fibronectin, laminin, etc.)
_______ receptors bind specific ECM components and initiate intracellular signaling.
Integrin
This type of CT is rich in ECM and mesenchymal stem cells (multipotent).
Embryonic CT
Embryonic CT has some but not as many collagen or reticular fibers. In the umbilical cord, it’s sometimes referred to as…
Wharton’s Jelly
This type of stem cell differentiate into a variety of cell types including: fibroblasts, muscle cells, osteoblasts, chondroblasts, and adipocytes.
Adult Mesenchymal Stem Cells
What are the types of loose CT?
Areolar
Adipose
Reticular
What are the types of dense CT?
Dense irregular
Dense regular
Elastic
This type of CT is a low density tissue with both fixed and wandering cells; widespread.
Areolar CT
***Loose
This type of CT is fat-containing.
Adipose
***Loose
This type of CT is rich in reticular fibers and forms an open framework to create a supportive mesh for holding free cells.
Reticular CT
***Loose
This type of CT has fibers that are deposited in a random pattern (i.e., Dermis of the skin).
Dense irregular CT
This type of CT has fibers that are deposited in a highly regular pattern (i.e., Tendons connecting skeletal muscle to bone).
Dense regular CT
This type of CT is rich in elastin fibers.
Elastic CT
***Dense
What are the fixed cells in Loose Areolar CT?
Fibroblasts
Adipocytes
Mesenchymal cells
What are the wandering cells in the Loose Areolar CT?
Macrophages
Mast cells
Leukocytes/Lymphocytes
Plasma cells
Loose CT functions to support and bind other tissues, hold body fluids, and defend against infection. It is found immediately beneath membranous epithelia, where it is referred to as the ________ ________. It is also around blood vessels, muscles, and nerves.
Lamina propria
This type of CT provides reserve energy source and insulates against heat loss. It also supports and protects organs (by padding and cushioning organ or filling space).
Adipose CT
This type of fat functions in energy storage, insulation, cushioning vital organs, and hormone secretion.
White fat
This type of fat is a key thermogenic tissue, abundant in newborns and greatly reduced in adults.
Brown fat
Reticular CT is rich in reticular fibers and forms an open framework to create a labyrinth for holding free cells. Where is it found?
Liver
Bone marrow
LNs
Spleen
This CT is in the ECM of tightly packed, interwoven collagen fibers running in a random pattern. Fibroblasts are the principle cell type.
Dense Irregular CT
Where is Dense Irregular CT found?
Dermis of skin
Capsules that surround internal organs
Perichondrium and periosteum
Fascia
This CT is in the ECM of tightly packed, regularly arranged collagen fibers. Fibroblasts are the principle cell type. It resists pulling forces and is poorly vascularized. When it’s not under tension it has a wavy appearance.
Dense Regular CT
Where is Dense Regular CT found?
Tendons
Ligaments
Aponeuroses
Dense fascia, joint capsules
This CT has a high proportion of elastic fibers. It allows recoil of tissue following stretching. It’s found in blood vessel walls, bronchiole tubes, and special ligaments (i.e., ligamentum nuchae).
Elastic CT
This is an autosomal dominant disorder where elastin is weak (mutation in fibrillin-I gene – component of elastin fibers). Principle targets are the ocular, skeletal, and cardiovascular systems. Patients have life threatening cardiovascular anomalies (i.e., dissecting aneurysms, mitral prolapse). They tend to be tall with long arms/legs.
Marfan’s Syndrome
The function of this is to produce the collagen, elastin, reticular fibers, proteoglycans, and glycoproteins in the ECM.
Fibroblasts
Adipocytes are closely packed with their ________ pushed to the side by large fat droplets.
Nuclei
These differentiate from blood monocytes. They function in phagocytosis and destruction of bacteria, damage or sick cells, removal of cell debris, and antigen processing and presentation to lymphocytes.
Macrophages
These cells secrete chemicals such as histamine that mediate the allergic response and heparin (an anti-coagulant of blood).
Mast cells
These are differentiated from B-lymphocytes and function to produce Abs that mediate immunity.
Plasma cells
