6-CONNECTIVE TISSUE Flashcards
CONNECTIVE TISSUE GENERAL TYPES
EMBRYONIC
ADULT
EMBRYONIC CONNECTIVE TISSUE types
Mesenchyme
Mucous tissue
ADULT CONNECTIVE TISSUE types
Ordinary/ Connective Tissue Proper
Specialized Connective Tissue
Ordinary/ Connective Tissue Proper types
Loose Connective Tissue
Dense Connective tissue (regular/ irregular)
Specialized Connective Tissue types
Cartilage
Bone
Blood
hematopoietic tissue`
COMPONENTS OF THE CONNECTIVE TISSUE
cells
fibers
ground substance
Major constituent of connective tissue is the
extracellular matrix (ECM)
made of: Protein fibers Ground substances
EXTRACELLULAR MATRIX (ECM) protein fibers
collagen, reticular, and elastic fibers
ECM Ground substance is a highly hydrophilic, viscous complex of
anionic macromolecules
Multiadhesive glycoproteins
anionic macromolecules in ecm
(glycosaminoglycans and proteoglycans)
Multiadhesive glycoproteins in ecm
(laminin, fibronectin, and others)
FUNCTIONS if connective tissue
SUPPORT AND PACKAGING
STORAGE
TRANSPORT
DEFENSE
REPAIR
connective tissue SUPPORT AND PACKAGING example
Tendons, ligaments, areolar tissue
Bone and cartilage
connective tissue STORAGE tissue examples
Lipids are stored in ADIPOSE TISSUE
LOOSE CONNECTIVE TISSUE stores water and electrolytes
serves as the medium through which nutrients and metabolic wastes are exchanged between cells and their nourishing blood supply
connective tissue matrix
DEFENSE EXAMPLE OF CONNECTIVE TISSUE
▪ Related to its content of phagocytic (macrophage) and antibody producing cells (plasma cells).
CELL TYPES in connective tissue
WANDERING OR MOBILE CELLS
FIXED CELLS
Permanent resident population
▪ Responsible for production and maintenance of extracellular components
▪ Storage for reserve fuel (fibroblasts, fat cells, undifferentiated mesenchymal cells, reticular cells)
FIXED CELLS
Transient emigrants from the bloodstream
▪ Concerned with the short term tissue reaction in injury
WANDERING OR MOBILE CELLS
WANDERING OR MOBILE CELLS EXAMPLES
(neutrophils, monocytes, lymphocytes, mast cells, plasma cells, macrophages)
Embryonic tissue where all types of connective tissues originate
MESENCHYME
Formed by elongated undifferentiated cells that are characterized by oval nuclei with prominent nucleoli and fine chromatin
MESENCHYME
______________ develops mainly from the middle layer of the embryo, the ________
MESENCHYME; mesoderm
Develops into other types of structures, such as blood cells, endothelial cells, and muscle cells.
MESENCHYME
CELLS OF CONNECTIVE TISSUE
Fibroblast
▪ Adipocytes
▪ Macrophages and the Mononuclear Phagocyte System
▪ Mast Cells
▪ Plasma Cells
▪ Leukocytes
Originate locally from undifferentiated mesenchymal cells and spend all their life in connective tissue
FIBROBLASTS
Synthesize collagen, elastin, glycosaminoglycans, proteoglycans and multiadhesive glycoproteins
FIBROBLASTS
are the most common cells in connective tissue
FIBROBLASTS
typically show large active nuclei and eosinophilic cytoplasm tapering off in both directions along the axis of the nucleus, a morphology usually called “spindle-shaped
FIBROBLASTS
Two stages of activity of fibroblasts
Active (fibroblast)
Quiescent (fibrocyte)
are large cells with large, euchromatic nuclei and basophilic cytoplasm (fibroblasts)
ACTIVE FIBROBLASTS
are smaller with less prominent, heterochromatic nuclei
INACTIVE FIBROBLAST or fibrocytes
Also known as fat cells
ADIPOCYTES
Connective tissue cells that have become specialized for storage of neutral fats or for the production of heat.
ADIPOCYTES
Connective tissue cells Incapable of mitotic division
ADIPOCYTES
ADIPOCYTES Can be stained with
osmic acid
ADIPOCYTES FUNCTIONS:
Storage of neutral fats or for the production of heat
key regulators of the body’s energy metabolism
Shock absorbers
As insulators
For protecting organs in the form of soft, elastic pad
For aesthetic purposes
TWO TYPES OF ADIPOSE TISSUE
White adipose tissue
Brown adipose tissue
the more common type
▪ composed of cells that, when completely developed, contain one large central droplet of whitish- yellow fat in their cytoplasm
White adipose tissue
▪ Contains cells with multiple lipid droplets interspersed among abundant mitochondria, which give these cells the darker appearance.
▪ has a much more limited distribution
Brown adipose tissue
o originate from hematopoietic stem cells in bone marrow
o are transient cells of most connective tissues
o also originate in the bone marrow and move to the connective tissue where they reside for a few days
o usually die by apoptosis
MAST CELLS, MACROPHAGES, AND PLASMA CELLS
were discovered and initially characterized by their phagocytic ability
Macrophages
Macrophages in EM are characterized by
an irregular surface with pleats, protrusions, and indentations
Generally have a well-developed Golgi apparatus, many lysosomes, and rough ER
MACROPHAGES AND THE MONONUCLEAR PHAGOCYTE SYSTEM FUNCTIONS:
o Important agents of defense
o Act as scavengers because of their mobility and phagocytic activity, engulfing extravasated blood cells, bacteria, foreign bodies and dead cells.
o Play a fundamental role in the development of immunity
Macrophages are Referred to as ________ once the phagocytosed particle, enclosed within the invaginated cell membrane.
phagosome
o macrophages that are stimulated
o change their morphological characteristics and metabolism
ACTIVATED MACROPHAGES
o has an increase in capacity for phagocytosis and intracellular digestion
o exhibit enhanced metabolic and lysosomal enzyme activity
ACTIVATED MACROPHAGES
Kupffer cells location and main function
Liver
Same as macrophages
Microglia cells cells location and main function
Nerve Tissue of the CNS
same as macrophages
Langerhans Cell cells location and main function
Skin
Antigen processing and presentation
Dentritic cells location and main function
Lymph nodes
Antigen processing and presentation
Osteoclast cells location and main function
Bone (fusion of several macrophages)
Digestion of bone
Multinuclear giant cells location and main function
Connective tissue (fusion of several macrophages)
Segregation and digestion of foreign bodies
Placenta macrophages
Hofbauer Cells
Adipose tissue macrophages
Adipose Macrophages
Are large, oval or round connective tissue cells, 20-30 m in diameter
Cytoplasm is filled with basophilic secretory granules.
Spherical nucleus is centrally situated and may be obscured by the cytoplasmic granules
MAST CELLS
displayed by mast cells because of high content of acidic radicals in their sulfated glycosaminoglycans
METACHROMASIA
which means that they can change the color of some basic dyes (eg, toluidine blue) from blue to purple or red.
METACHROMASIA
A PARTIAL LIST OF IMPORTANT MOLECULES RELEASED FROM TE GRANULES INCLUDES
Heparin
Histamine
Serine proteases
Eosinophil and neutrophil chemotactic factors
Leukotrienes C4, D4, and E4 (SRS-A)
a sulfated glycosaminoglycan that acts locally as an anticoagulant
Heparin
promotes increased vascular permeability and smooth muscle contraction
Histamine