Studied by 23 people
Germ layers
Ectoderm mesoderm endoderm
What tissues are in mesoderm
Embryonic connective tissues : mesenchyme and muscle
2 types of adult connective tissue
Connective tissues proper and specialized connective tissues
Connective tissues proper
Loose
Reticular
Adipose
Dense
Specialized connective tissues
Cartilage (supporting ct)
Bone (supporting ct)
Blood (fluid ct)
Connective tissues
Cells and extracellular matrix ( includes ground substance and fibers)
Types of cells
Fibroblasts and fibrocytes
Histiocytes
Mast cells
Myofibroblasts
Melanocytes
Leukocytes
Plasma cells
Pericytes
Fat cells
Ground substance
Glycosaminoglycans
Glycoproteins
Proteoglycans
Glycosaminoglycans
Hyluronic acid
Chondroitin 4-sulfate
Chondroitin 6-sulfate
Dermatan sulfate
Heparan sulfate
Proteoglycans
Aggrecan
Others
Glycoproteins
Fibronectin
Laminin
Others
Fibers
Colagen
Reticular
Elastic
Fibroblasts
Most common cell type in connective tissue
Synthesise fibers
Synthesise ECM (glycosaminoglycans and glycoproteins)
Fibrocytes (7 points)
Smaller then fibroblasts
Spindle shape
Fewer processes
Darker
Elongated nucleus
Acidophilic cytoplasm
Small amount of RER
Mast cells, characteristics and secretes
Round oval
Basophilic granules in cytoplasm
Secretes:
Heparin
Histamine
ECF-A
NCF-A
leukotrienes
Prostaglandin
Thromboxane
Platelet activing factor
Histocytes 4 points
Irregular shape
Nucleus : oval eccentric kidney shape
Granular lysosomes
Pseudopodia
Function macrophages
Particulate matter such as dust
Participate in the breakdown of aged cells including erythrocytes
Ingestion by phagocytosis
Microorganisms:
Bacteria
Viruses
Fungi
parasites
Plasma cells 6 points
Derive from B lymphocytes
Eccentric nucleus
Dark staining cytoplasm
Lots of RER
Don’t leave the connective tissue
Produce antibodies
Pericytes 3 points
Associated with small blood vessels, contractile cells and pluripotential
Types of leukocytes
Limphocytes
Granulocytes
Monocytes - macrophages = histiocytes
Limphocytes
B Limphocytes
T Limphocytes
Natural killer
Granulocytes
Neutrophils
Eosinophils
Basophils
The mononuclear phagocyte system
Histiocytes of ct
Kupffer cells of the liver
Alveolar macrophages of the lung
Osteoclasts
Microglia
Myofibroblasts
Part fibroblasts and part muscle like cells
Having a contractile apparatus similar to the smooth muscle cells
Injury repair after wounding
Melanocytes
Pigment cells found in the connective tissues, the skin and the eye
The melanin produced by these cells is known to absorb ultraviolet light violet
Resident or permanent cells
Fibroblasts
Mast cells
Histiocytes
Plasma cells
Pericytes
Transient cells
Leukocytes
Other cells
Myofibroblasts
Melanocytes
Fat cells
The main types of collagen
Collagen type I, II, III, IV
Collagen type I (90% all collagen)
Made by fibroblasts, osteoblasts
Forms bones, tendons, skin
Collagen type II
Forms fibrils not fibers
Made by chondroblasts
Found in cartilage
Collagen type III
Made by fibroblasts, reticular cells, smooth muscle cells, Schwann cells, hepatocyte
Component of reticular fibers in lymphoid organs
Occurs in the tissues and organs of the lymphatic system, liver, bone marrow
Collagen type IV
Made by endothelial cells, epithelial cells, muscle cells, Schwann cells
Found in blood vessels, epidermis, lining body cavities, skeletal and smooth muscle, heart, nerve fibers
Elastic fibers
Occurrence:
Connective tissue proper
Elastic cartilage
Skin
Arteries
Veins
fetal tissue
Loose connective tissue
Cells
Fibers (collagenous most abundant, elastic not as common, reticular found where lct borders on other tissues)
Ground substance (amorphous jelly thought to occur in sheet like lamellae)
Occurrence of loose connective tissue
Attaches epithelial layers to underlying tissues
A general bedding substance in the interiors of many organs
Located around blood vessels, nerves and ducts
A packing material in spaces between tissues
Functions of loose connective tissue
Support stroma (support with mobility, increases elasticity, provides pathways for blood vessels and nerves, packs unused spaces in body)
Transport (allows movement of food, oxygen and waste)
Defense (phagocytic cells in tissue destroy microbes)
Repair (fibroblasts produce new fiber and ground substance)
Irregular dense connective tissue
Random bundles of collagen fibres
Major cell type is fibroblasts
Found in dermis, sub mucosa of digestive system and fibrous organ capsules
Regular dense connective tissue
Closely packed fibre bundles
Major cell type is fibroblasts
Attaches muscle to bone or other muscles and bone to bone
Found in tendons, ligaments and aponeuroses
Reticular connective tissue
Stellate shaped cells
Forms network of thin fibres
In bone marrow
In lymphoid organs
Adipose tissue
To store energy in form of lipids
Heat production
To produce:
Adiponectin
Resistin
Plasminogen activator inhibitor-1
TNFa
IL-6
Leptin
Estradiol
Adipose tissues also secrete a type of cyokines called adipokines
White adipose tissue occurence
Occurs beneath the skin
Around internal organs
In bone marrow
In breast tissue
Brown adipose tissue occurrence
In newborn of all mammals
In species that hibernate
In man
General features of connective tissue
Contain less cells and more intercellular substance
No polarity
Blood vessels and nerves
Widely distributed
Functions of connective tissue proper
Stroma
Protection
Transport
Defense
Storage
