Connective Tissue Flashcards
What is the structure/function of connective tissue?
Tissue that supports, protects, and gives structure to other tissues and organs.
All share specialized cells and ECM
What are the functions of connective tissue?
Structural framework for the body Transport fluids/dissolved materials Protect/insulate organs Support/connect other tissues Store energy as triglycerides Immune response Compartmentalize structures
Where is connective tissue located?
Bone, cartilage, fat, blood, lymph
What is the extracellular matrix made of?
Ground substance, connective tissue fibers, and extracellular adhesion molecules
What is ground substance made of?
Extracellular fluid, proteoglycans and hyaluronic acid
What are extracellular adhesion molecules made of?
Fibronectin (connective tissue proper), osteonectin (bone), chondronectin (cartilage)
What are connective tissue fibers made of?
Collagen fibers, elastic fibers, reticular fibers
Describe collagen fibers
Long, straight, unbranched, strong fibers made of different types of collagen.
Most common fiber in connective tissue proper
Collagen
The most abundant protein in the body
Where are collagen fibers found?
Tendons and ligaments
Describe reticular fibers
Fine, branched fibers continuous with collagen fibers.
Forms stroma
Stroma
A network of interwoven fibers in reticular connective tissue
Where are reticular fibers found?
Spleen, liver, lymph nodes, red bone marrow
Describe elastic fibers
Small, strong, branched, flexible fibers made of elastin and fibrillin
Where are elastic fibers found?
Elastic ligaments of vertebrae, skin, lungs, walls of blood vessels
Fibroblasts
Most abundant cell type found in all connective tissue proper.
Large, flat cells with branching processes.
SECRETE protein fibers and some components of the ground substance
Fibrocytes
The second most abundant cell type found in all connective tissue proper.
MAINTAINS the fibers of connective tissue proper
Adipocytes
Fat cells, each storing a single fat droplet
Mesenchymal cells
Stem cells that respond to injury or infection
What do mesenchymal cells differentiate into?
Fibroblasts, chondoblasts, osteoblasts, hemocytoblasts, macrophages
Mast cells
Stimulate inflammation after injury or infection
Histamine
Inflammatory agent
Heparin
Anticoagulant agent (prevents blood clots)
Macrophages
Large, amoeba-like cells of the immune system that eat pathogens and damaged cells
What are the two subtypes of macrophages?
Fixed macrophages (stay in tissue) Free macrophages (migrate)
What are the three types of mature connective tissues?
Connective tissue proper, fluid connective tissue, supporting connective tissue
Characteristics of connective tissue proper
- Many types of cells and EC fibers
- Viscous ground substance
- Variety (loose & dense) based on number of cell types present, and proportions of connective tissue fibers to ground substance
Characteristics of supporting connective tissues
- Less diverse cell population
- Gelatinous or calcified ground substance with densely packed connective tissue fibers
- Provides structural strength and support
What are the two types of connective tissue proper?
Loose and dense
Characteristics of loose connective tissue
“Packing materials” of the body that fill spaces between organs.
More ground substance than connective tissue fibers.
What are the three types of loose connective tissue?
Areolar, adipose, and reticular tissues
What is the structure/characteristics of areolar tissue?
Open framework of collagen, elastic, and reticular fibers.
Least specialized; most diverse cell population.
Viscous ground substance absorbs shocks.