• Types and functions:
– Loose connective tissue: fat, areolar –
– Dense Connective: Ligaments and tendons –
binding and support
– Cartilage – protection, support
– Bone - support
– Blood- transportation
• All Connective tissue share the following
characteristics, despite the variety.
– Develop from the same embryonic tissue
– Composed of many different types of cells
within the tissue.
– Contains extracellular matrix
– Great variation in the amount of blood
Cells in Matrix
• Cells in connective tissue make and maintain
the ground substance and fibers.
• Each type of conn. Tissue have immature and
mature forms of these cells.
• Immature cells have suffix “-blast” – actively
• Mature cells have suffix “-cyte” – maintain
health of matrix, reverting to blasts to
regenerate matrix after injury.
– Fibroblasts – make conn. Tissue/fibers
– Chondroblasts – make cartilage,
– Osteoblasts – make bone
– Hematopoeitic stem cells – make blood
Cells in Matrix
• Other cells present:
– White blood cells (macrophages, plasma
cells)– responsible for immune response
– Mast cells – responsible for inflammation
following injury or infection.
• Extracellular matrix is the substance that
connective cells are embedded within.
• Made of nonliving material called ground
– Can be liquid, gel-like, semi-solid or hard.
– Texture depends on amount of cell adhesion
proteins: proteoglycans which trap water forming a
gel. More proteins, more solid ground substance.
• Contains fibers that provide great strength, or
flexibility, or both.
• Extracellular matrix allows Conn. Tissue to
bear weight, mechanical abuse – protects!!
• Fibers are embedded in ground substance
to add strength/flexibility.
• Dense fibous (Collagen): stronger than steel
of the same size. STRENGTH!
1. Regularly arranged in tendons,ligament
2. Irregularly arranged: in dermis give
elasticity to the skin
• Dense Irregular
– Fibers run in different directions.
– Tissue is found where tension is applied in
– Example: Dermis of skin
Fun : connection
•Reticular: delicate, forms nets
that support free cells.
– Only contains reticular fibers.
– VERY DELICATE – a fine net of fibers.
– Supports free blood cells.
– Found in lymph nodes, bone
Loose Connective Tissue
• Areolar – most widely distributed type.
– Serves as “packing material” cushioning
organs, subcutaneous, attaches skin to
– Contains all three fibers
– Very loosely packed, lots of liquid
– Swells during inflammation (edema)
• Adipose = Fat!
– Loosely packed with little matrix
– Highly cellular : 90% of tissue is adipocytes
– Nutrient storage, cushioning.
– Richly vascularized
– Develops within areolar tissue/subcutaneous
• 18% of an average person’s weight
• 50% of chubby person
– Resists tension and pressure
– Tough and flexible
– No nerves or blood vessels
– Lots of collagen and elastic fibers.
– 80% water
– Chondroblasts make matrix until end of human
– Mature Chondrocytes found in cavities called
– Condrotin sulfate give matrix semisolid property
• Looks glassy (hyalin = glass)
• Few chondrocytes, all located in lacunae
• Mostly matrix – lots of collagen
• Reduces friction, absorbs pressure
• Covers ends of bones, connects ribs to
sternum, forms rings in trachea and
• Looks almost identical to hyaline
• Matrix appears more fibrous
• Many more elastic fibers – makes it very
• Found in nose, ear and epiglottis
• Fun: maintain shape, support.
• Very tough, almost like bone
• Consists of rows of chondrocytes and
• Withstands great pressure
• Found in intervertebral discs.
• Most supportive tissue in body.
• Matrix is composed of collagen fibers
surrounded by calcium salts.
• Osteoblasts make collagen fibers and calcium
salts deposited between fibers.
• Well vascularized
• Osteocytes stored in lacunae
• Bone marrow stores fat and makes blood
• Atypical connective tissue
• Only classified as such because it arises
from same embryonic tissue
• Blood cells are within a matrix of blood
• Fibers apparent only when blood clots.