Lecture 4 - Connective Tissue & ECM Flashcards
List the parts of the ECM.
Fibers, amorphous ground substance, & tissue fluid
List the functions of CT.
1) structural support 2) exchange medium between blood and tissues 3) defense and protection 4) fat storage
What type of cells do fibroblasts arise from?
Mesenchymal cells
What is the difference between a fibroblast and a fibrocyte?
Fibroblasts = active/high synthesis; Fibrocyte = inactive/low synthesis (slimmer in appearance as a result)
What type of cells do adipocytes arise from and what are they surrounded by?
Mesenchymal cells, basal lamina
What type of receptors do unilocular adipocytes possess?
Insulin, growth hormone, norepinephrine, glucocorticoid
What type of tissue and cell do macrophages arise from?
originate from bone marrow as monocytes
Macrophages migrate from blood into connective tissue & various organs and take on different phenotypes. What are 3 primary sites of migration and what are the names for the specialized macrophages at each site?
Liver - Kuppfer cells
Osteoclasts - bone
Microglia - CNS
Macrophages have two primary functions. What are they?
1) Phagocytic
2) Regulate immune system
What type of immune regulators to macrophages secrete?
Prostaglandins, interleukins, TNF-alpha
What type of cells do Mast cells arise from?
Myeloid stem cell
What specific type of hypersensitivity reaction do Mast cells mediate?
Type 1 hypersensitivity (asthma, hay fever, eczema)
What effect to Mast cell immune mediators have?
Increase inflammatory response (vasoactive)
What mediators do Mast cells release? (There are 7 listed in the notes)
Leukotriene C, heparin, histamine, eosinophil chemotactic factor, neutrophil chemotactic factor, aryl sulfatase, neutral protease
What tissues do Mast cells occur in?
Respiratory or GI (mucosal) and connective tissue
How to Mast cells interact with IgE?
Possess Fc receptor for Fc on IgE
From what type of cells do plasma cells arise? What is their function?
Activated B lymphocyte, antibody producing (humoral immunity)
What imaging characteristic is a hallmark of plasma cells?
Hemotoxylin (basophilic) stained cytoplasm (protein of rER) and negative staining golgi (adjacent to nucleus)
What cells do lymphocytes arise from and what cell types do they produce?
Arise from lymphoid stem cells. Produce T cells (cell mediated immunity), which differentiate in thymus, and B cells (humoral immune response).
What type of cell possesses a characteristic trilobed nucleus?
Neutrophil
What immune cell appears first at the site of inflammatory reaction?
Neutrophil
What immune cell type is biolobed?
Eosinophil
What specific enzymes do eosinophils contain and what is their job upon secretion?
Leukotriene C and histamine - moderate allergic reaction
What immune cell type is integrally involved in parasite immune response? Additionally, how do these immune cells associate/mitigate parasites?
Eosinophil, bind to antigen-Ab complex on parasite surface and release cytotoxins
Where are pericytes found?
Around capillaries
What cell types can pericytes differentiate into?
Fibroblasts & smooth muscle
List the types of embryonic connective tissue (2) and state where these types are found.
1) Mesenchymal CT - present in embryos
2) Mucous CT (aka Wharton’s jelly) - main component of umbilical cord
What makes up mesenchymal CT?
amorphous matrix with some reticular fibers and mesenchymal cells (a small sub-pop may be stem cells)
What makes up mucous CT?
collagen and fibroblasts (jelly like)
List the types of connective tissue proper.
1) Loose (areolar) CT
2) Dense CT - regular (only found in ligaments, tendons) and irregular
3) Reticular tissue
4) Adipose tissue
Lists type of specialized CT.
bone, cartilage, blood
What does ECM consist of (3 parts)?
1) ground substance 2) fibers 3) tissue fluid
What does ground substance consist of?
proteoglycans
What is a proteoglycan?
core protein with a covalently linked glycosaminoglycan