Connective tissue Flashcards
Four types of Connective Tissue proper
- loose (lamina propria)
- dense
- elastic regular (ligaments, tendons)
- irregular (dermis)
Four types of Connective Tissue with special properties
- Adipose Tissue
- Elastic Tissue
- Hematopoietic (lymphatic and myeloid)
- Mucous Tissue
Two types of supporting connective tissue
- cartilage
2. bone
Cell type: Fibroblast, chondroblast, osteoblast, odontoblast
Production of fibers and ground substance; structural function
Cell Type: Plasma cell
production of antibodies; immunologic (defense) function
Cell type: Lymphocyte
Production of immunocompetent cells; immunologic (defense) function
Cell Type: Eosinophilic leukocyte
Participation in allergic and vasoactive reactions, modulation of mast cell activites and the inflammatory proces; immunologic (defense) function
Cell Type: Neutrophilic leukocyte
Phagocytosis of foreign substances, bacteria; defense function
Cell Type: Macrophage
Secretion of cytokines and other molecules, phagocytosis of foreign substances and bacteria, antigen processing and presentation to other cells; defense function
Cell Type: Mast Cell and basophilic leukocyte
liberation of pharmacologically active molecules (e.g. histamine) (Inflammatory Response); Defense (participated in allergic reactions) function
Cell Type: Adipose (fat) cell
Storage of neutral fats; energy reservoir and heat production function
Components of Connective Tissue
a) cellular
b) Extracellular Matrix
i. amorphous (ground substance)
ii. fibrous
Cellular component:
i. fibroblasts
ii. adipose cells
iii. macrophages
iv. mast cells
v. leukocytes
vi. plasma cells
Multilocular Adipocyte: Brown Fat
- Multiple lipid droplets
- Abundant mitochondria
- More readily able to generate heat in neonates
Plasma cells are characterized by:
- eccentric nucleus
- cartwheel arrangement of heterochromatin
- abundant rough endoplasmic reticulum to make immunoglobulins
Mast Cell secretion:
- IgE molecules are bound to the surface receptors
- After a second exposure to the antigen, IgE molecules bound to surface receptors are cross linked by the antigen. This activates adenylate cyclase and results in the phosphorylation of certain proteins.
- At the same time, Ca2+ enters the cell
- These events lead to intracellular fusion of specific granules and exocytosis of their contents
- In addition, phospholipases act on membrane phospholipids to produce leukotrienes. The process of extrusion does not damage the cell, which remains viable and synthesizes new granules.
Extracellular Matrix: amorphous
- glycosaminoglycans (sugars)
- proteoglycans (combination of proteins)(unbranched)
- glycoproteins (branched)
Hyaluronic Acid: GAGs
unbranced polymeric disaccharide containing amino sugars
Proteoglycans are extracellular protein complexes of?
glycosaminoglycans
Proteoglycans aggegates are formed by:
- An axial hyaluronan molecule
- Core proteins attached to the hyaluronan molecule by a linker protein
- Glycosaminoglycans
Several chains of glycosaminoglycans bound to the core protein form a ?
proteoglycan
The molecular mass of proteoglycan is about
10^8 Da
____ replace cadherins in hemidesmosomes
integrins
Extracellular Matrix: fibrous
a. collagen fibers
b. reticular fibers (type III collagen)
c. elastic fibers (fibrillin, elastin)
Functions of collagens (4)
- Adhesion - discrete and restricted to cells and tissues
- Skeletal - established in vertebrates
- Protective - dermis (leather)
- Messenger - acts on cell behavior
Which stain is the most common to visualize elastic fibers in tissue sections?
Orcein (brownish-red)
Characteristic of reticular fibers (3)
- type III collagen
- enriched in lymphoid organs and tissues
- stain black with silver based stains (argenophylic)
