lesson 4: Connective tissue Flashcards
What are the four basic tissue types?
Connective, epithelial, muscle, nervous.
What are the general characteristics of connective tissue?
Very few cells, separated cells, abundant ECM, fibers, ground substance, derives from mesoderm.
What are the main functions of connective tissue?
- Connection between tissues - tendons and ligaments
- Support
- Energy storage (adipose tissue)
- Insulation and protection (adipose, cartilage)
- Transport (e.g., red blood cells)
- Protection against infections (e.g., white blood cells)
What is the ground substance in connective tissue?
Fills the space between cells and fibers, very hydrated gel.
What are glycosaminoglycans (GAGs)?
Sugars, e.g., hyaluronic acid.
What are glycoproteins in connective tissue?
Adhesion proteins, e.g., laminin.
What are the three types of fibers in connective tissue?
- Collagen fibers
- Reticular fibers
- Elastic fibers
What is the role of collagen fibers?
Provide resistance and are made of collagen, very resistant.
What is the significance of Vitamin C in collagen synthesis?
Critical for collagen synthesis by fibroblasts; deficiency can cause poor healing.
What are reticular fibers made from?
Collagen type III.
What are elastic fibers made from?
Elastin.
What are resident cells in connective tissue?
Formed by mesenchymal cells, stay permanently in tissue.
What are mesenchymal cells?
Stem cells with the ability to develop into different cell types.
What is the function of fibroblasts?
Synthesize the ECM (GAGs and collagen).
What happens to fibroblasts after they synthesize ECM?
They differentiate into fibrocytes.
What is the function of fibrocytes?
Maintain the ECM.
What do fibroclasts do?
Degrade the ECM.
What do adipocytes store?
Lipids, specifically triglycerides.
What is the function of macrophages?
Phagocytosis of malfunctioning cells, microorganisms, and debris.
What are transient cells?
Formed in bone marrow, circulate in bloodstream, temporary visitors in connective tissue.
What triggers mast cells to activate?
Allergic substances.
What do mast cells release?
- Histamine (triggers vasodilation and inflammation)
- Heparin (anticoagulant)
What is the role of lymphocytes?
Mediators of the immune response, protection against pathogens.
What are the two types of immunity mediated by lymphocytes?
- Humoral immunity (antibodies)
- Cell-mediated immunity (cells)
