Lesson 4: Connective Tissue Flashcards
What are the main components of connective tissue?
Cells, fibers, and extracellular matrix (ECM).
composed by different cell types but all deriving from mesenchyme cells of mesoderm origin
What are the primary functions of connective tissue?
Support, protection, transport, insulation, and storage of energy.
The composition of the ECM determines the charachteristics and function of each connective tissue
How is connective tissue classified?
Into connective tissue proper (non-specialized),
supportive connective tissue, and fluid connective tissue (specialized).
What is the embryonic origin of connective tissue?
Mesoderm.
What are the two types of embryonic connective tissue?
Mesenchyme and mucous connective tissue.
What is mesenchyme composed of?
Star-shaped mesenchymal cells, ground substance, and reticular fibers.
Where is mucous connective tissue found?
In the umbilical cord as Wharton’s jelly.
What are the two subtypes of connective tissue proper?
Loose connective tissue and dense connective tissue.
Where is loose connective tissue commonly found?
Beneath epithelia and around blood vessels and nerves.
What are the two types of dense connective tissue?
Dense regular and dense irregular connective tissue.
What is the primary function of dense regular connective tissue?
To provide tensile strength in one direction (e.g., tendons, ligaments).
How does dense irregular connective tissue function?
Provides strength in multiple directions (e.g., dermis of the skin).
What are the resident cells of connective tissue?
Fibroblasts, macrophages, mast cells, and adipocytes.
What are the transient cells in connective tissue?
White blood cells (lymphocytes, neutrophils, eosinophils, and monocytes), plasma cells, macrophages.
What is the primary role of fibroblasts?
To synthesize collagen, elastic and reticular fibers, and ECM carbohydrates.
How do macrophages contribute to immunity?
They phagocytose pathogens and present antigens to lymphocytes.
What do mast cells release during inflammation?
Histamine, heparin, and cytokines.
What is the function of adipocytes in connective tissue?
Energy storage, insulation, and cushioning.
What are the main components of ECM?
Protein fibers (collagen, elastic, reticular) and ground substance.
What is the role of ground substance?
To provide a medium for diffusion and resist compression.
Made of : water, electrolytes, Specialized molecules: glycoproteins, glycosaminoglycans, proteoglycans, enzymes
What are glycosaminoglycans (GAGs)?
Long unbranched polysaccharides that attract water and resist compression.
What is the function of proteoglycans in ECM?
To provide structural support and facilitate cell signaling.
Connection, anchoring and support of the body and its organs
Transport of metabolites between capillaries and tissues
Repair of injury (via cell proliferation and fibers formation)
Cell differentiation, activation, localization
Name examples of adhesive glycoproteins in ECM.
Fibronectin and laminin.
What is the most abundant protein in the human body?
Collagen.
What are the main types of collagen and their locations?
Type I (skin, tendons, bone, cornea)-most common type, Type II (cartilage), Type III (reticular fibers, loose c.t., blood vessel walls, dermis), Type IV (basal lamina of epithelium and kidney glomeruli).
What is the role of collagen fibers?
To provide tensile strength and structural integrity and resist mechanical stress.
What is the function of elastic fibers?
To allow tissues to stretch and recoil.
Where are elastic fibers commonly found?
Skin, large arteries, and elastic cartilage.
What are reticular fibers made of?
Type III collagen.
What is the role of reticular fibers?
To form supportive frameworks for organs such as lymph nodes and bone marrow.
What are the two types of adipose tissue?
White adipose tissue and brown adipose tissue.
What is the primary function of white adipose tissue?
Energy storage and cushioning.
What is the function of brown adipose tissue?
Heat production through thermogenesis.
Where is brown adipose tissue predominantly found?
In newborns and around the neck and thorax in adults.
What are examples of specialized connective tissue?
Cartilage, bone, blood, and lymph.
What is unique about cartilage ECM?
It contains chondroitin sulfate and aggrecan for resilience.
What are the three types of cartilage?
Hyaline cartilage, elastic cartilage, and fibrocartilage.
What distinguishes fibrocartilage from other types?
It has abundant collagen fibers for tensile strength and lacks a perichondrium.
Where is elastic cartilage found?
In the external ear, epiglottis, and Eustachian tube.
What are the two types of bone tissue?
Compact bone and spongy bone.
What cells are involved in bone resorption?
Osteoclasts.
What cells maintain bone matrix?
Osteocytes.
What is the basic structural unit of compact bone?
The osteon or Haversian system.
What are the phases of wound healing?
Inflammatory phase, proliferative phase, and remodeling phase.
What is the role of fibroblasts during wound healing?
To produce new collagen and ECM components.
What type of collagen predominates in scar tissue?
Type I collagen.