Connective Connective TissueTissue

Connective TissueConnective Tissue

Binds together, supports and Binds together, supports and strengthens other body tissuesstrengthens other body tissues

Protects and insulates internal organsProtects and insulates internal organs Compartmentalizes structures such as Compartmentalizes structures such as

skeletal muscleskeletal muscle The major transport system within the The major transport system within the

bodybody Site of stored energy reservesSite of stored energy reserves Main site of immune responsesMain site of immune responses

General Features of General Features of Connective TissueConnective Tissue

2 basic parts:2 basic parts: Cells and MatrixCells and Matrix

Matrix – material between widely Matrix – material between widely spaced cellsspaced cells Consists of protein fibers and ground Consists of protein fibers and ground

substancesubstance Ground substance – material between cells Ground substance – material between cells

and fibers secreted by the cells and and fibers secreted by the cells and determine the tissue qualitiesdetermine the tissue qualities

General Features of General Features of Connective TissueConnective Tissue

Does not occur on free surfacesDoes not occur on free surfaces Has a nerve supply (except Has a nerve supply (except

cartilage)cartilage) Highly Vascular (except cartilage Highly Vascular (except cartilage

and tendons)and tendons)

Connective Tissue CellsConnective Tissue Cells Fibroblasts – large flat cells with branching Fibroblasts – large flat cells with branching

processes. Migrate throughout connective processes. Migrate throughout connective tissue secreting the fibers and ground tissue secreting the fibers and ground substancesubstance

Macrophages – develop from white blood Macrophages – develop from white blood cells. Surround and engulf material by cells. Surround and engulf material by phagocytosisphagocytosis

Mast Cells – alongside blood vessels that Mast Cells – alongside blood vessels that supply connective tissue. Produce histamine supply connective tissue. Produce histamine – a chemical that dilates blood vessels.– a chemical that dilates blood vessels.

Adipocytes – “fat cells” store triglycerides.Adipocytes – “fat cells” store triglycerides.

Connective Tissue Matrix – Connective Tissue Matrix – Ground SubstanceGround Substance

Ground Substance – component of a Ground Substance – component of a connective tissue between the cells connective tissue between the cells and fibers, supports cells, binds and fibers, supports cells, binds them together, and provides a them together, and provides a medium through which substances medium through which substances are exchanged.are exchanged. Ex. Hyaluronic AcidEx. Hyaluronic Acid

Connective Tissue Matrix – Connective Tissue Matrix – FibersFibers

Strengthens and supports connective Strengthens and supports connective tissuetissue Collagen FibersCollagen Fibers

Strong, resist pulling forces, flexibleStrong, resist pulling forces, flexible Made of the protein collagen which is the most Made of the protein collagen which is the most

abundant protein in your bodyabundant protein in your body Elastic FibersElastic Fibers

smaller in diameter than collagen fibers, branch smaller in diameter than collagen fibers, branch to form networkto form network

Made of the protein elastinMade of the protein elastin Reticular FibersReticular Fibers

Provide support for the walls of blood vesselsProvide support for the walls of blood vessels Made of collagen with a glycoprotein coveringMade of collagen with a glycoprotein covering

Marfan SyndromeMarfan Syndrome

An inherited disorder caused by a defective An inherited disorder caused by a defective gene for the glycoprotein fibrillin resulting gene for the glycoprotein fibrillin resulting in abnormal development of elastic fibers. in abnormal development of elastic fibers. This causes tissues that contain many This causes tissues that contain many elastic fibers to be malformed or weak elastic fibers to be malformed or weak (including the covering of bone, ligament (including the covering of bone, ligament that suspends the lens of the eye, and the that suspends the lens of the eye, and the walls of large arterieswalls of large arteries

People with Marfan syndrome are often tall, People with Marfan syndrome are often tall, have long arms, legs, fingers and toes, have long arms, legs, fingers and toes, blurred vision, and weakened aortic walls blurred vision, and weakened aortic walls that may burst.that may burst.

Types of Connective Types of Connective TissueTissue

There are 6 types of connective There are 6 types of connective tissue that vary by the fibers, ground tissue that vary by the fibers, ground substance and cells contained in it. substance and cells contained in it. Each type has a very specific Each type has a very specific structure and function.structure and function.

Loose Connective TissueLoose Connective Tissue

Fibers are loosely intertwined Fibers are loosely intertwined among many cells. among many cells.

3 types of loose connective tissue3 types of loose connective tissue Areolar Connective Tissue – one of the Areolar Connective Tissue – one of the

most widely distributed connective most widely distributed connective tissues in the body. tissues in the body. Contains fibroblasts, macrophages, plasma Contains fibroblasts, macrophages, plasma

cells, mast cells, adipocytes and a few white cells, mast cells, adipocytes and a few white blood cells as well as all 3 types of fibersblood cells as well as all 3 types of fibers

Helps to form the subcutaneous layerHelps to form the subcutaneous layer

Loose Connective TissueLoose Connective Tissue Adipose Tissue – The cells, called adipocytes, Adipose Tissue – The cells, called adipocytes,

are specialized for storage of triglycerides. are specialized for storage of triglycerides. Adipocytes fill up with a large fat droplet so Adipocytes fill up with a large fat droplet so the nucleus gets pushed to one side of the cell.the nucleus gets pushed to one side of the cell.

Used for insulation, protection and as an energy Used for insulation, protection and as an energy reservereserve

Reticular Connective Tissue – made of Reticular Connective Tissue – made of interlacing reticular fibers and reticular cells interlacing reticular fibers and reticular cells that connect to each other to form a network. that connect to each other to form a network.

Used to bind together smooth muscle cells and to Used to bind together smooth muscle cells and to filter out worn out blood cells and bacteriafilter out worn out blood cells and bacteria

Dense Connective TissueDense Connective Tissue

Contains more numerous, thicker Contains more numerous, thicker and denser fibers but fewer cells and denser fibers but fewer cells than loose connective tissue.than loose connective tissue.

3 types:3 types: Dense regular connective tissueDense regular connective tissue Dense Irregular connective tissueDense Irregular connective tissue Elastic Connective TissueElastic Connective Tissue

Dense Regular Dense Regular Connective TissueConnective Tissue

Bundles of collagen fibers are Bundles of collagen fibers are arranged regularly in parallel arranged regularly in parallel patterns that give it strength.patterns that give it strength.

Withstands pulling from the ends, but Withstands pulling from the ends, but unravels when pulled from the sideunravels when pulled from the side

Silvery white in appearance. Tough Silvery white in appearance. Tough and pliableand pliable

Found in tendons and ligamentsFound in tendons and ligaments

Dense Irregular Dense Irregular Connective TissueConnective Tissue

Collagen fibers are packed closely Collagen fibers are packed closely together in an irregular, random together in an irregular, random patternpattern

Found in parts of the body where Found in parts of the body where pulling forces are exerted in various pulling forces are exerted in various directionsdirections

Usually found in sheetsUsually found in sheets Examples: Dermis of the skin, heart Examples: Dermis of the skin, heart

valves, perichondrium and periosteumvalves, perichondrium and periosteum

Elastic Connective TissueElastic Connective Tissue

Contains branching elastic fibers Contains branching elastic fibers and fibroblastsand fibroblasts

Yellowish in colorYellowish in color Strong, can regain shape after Strong, can regain shape after

stretchingstretching Found in lungs and arteriesFound in lungs and arteries

CartilageCartilage

Dense network of collagen fibers and Dense network of collagen fibers and elastic fibers embedded in elastic fibers embedded in chondroitin sulfate (a rubbery chondroitin sulfate (a rubbery component of the ground substance)component of the ground substance)

Can withstand more stress than the Can withstand more stress than the dense and loose connective tissue.dense and loose connective tissue.

Collagen fibers make the tissue Collagen fibers make the tissue strong, chondroitin sulfate makes it strong, chondroitin sulfate makes it resilientresilient

Cartilage - continuedCartilage - continued

Chondrocytes – mature cartilage cellsChondrocytes – mature cartilage cells Lacunae – holes in the matrix in which Lacunae – holes in the matrix in which

the cells sitthe cells sit Perichondrium – dense irregular Perichondrium – dense irregular

connective tissue that surrounds cartilageconnective tissue that surrounds cartilage 3 types – hyaline, fibrocartilage and 3 types – hyaline, fibrocartilage and

elasticelastic Cartilage is AVASCULAR and NO nerve Cartilage is AVASCULAR and NO nerve

supply (but the perichondrium does)supply (but the perichondrium does)

Hyaline CartilageHyaline Cartilage

Gel like ground substance, collagen Gel like ground substance, collagen fibers (not visible with normal fibers (not visible with normal stains) and prominent chondrocytesstains) and prominent chondrocytes

Most abundant cartilage in the bodyMost abundant cartilage in the body Found at the end of long bones to Found at the end of long bones to

cushion joints and at epiphyseal cushion joints and at epiphyseal plates (growth plates in bones)plates (growth plates in bones)

Weakest of the 3 types of cartilageWeakest of the 3 types of cartilage

FibrocartilageFibrocartilage

Chondrocytes scattered among Chondrocytes scattered among visible bundles of collagen fibersvisible bundles of collagen fibers

No perichondriumNo perichondrium Strongest of the 3 types of cartilageStrongest of the 3 types of cartilage Found in the intervertebral discsFound in the intervertebral discs

Elastic CartilageElastic Cartilage

Chondrocytes located in a threadlike Chondrocytes located in a threadlike network of elastic fibersnetwork of elastic fibers

Provides strength, elasticity and Provides strength, elasticity and maintains the shape of certain maintains the shape of certain structures (like the external ear)structures (like the external ear)

Bone Tissue (osseous Bone Tissue (osseous tissue)tissue)

2 types – compact and spongy2 types – compact and spongy CompactCompact

Osteon – basic unit of compact boneOsteon – basic unit of compact bone Lamellae – concentric circles of matrixLamellae – concentric circles of matrix Lacunae – spaces in the matrix that house Lacunae – spaces in the matrix that house

cellscells Osteocytes – mature bone cellsOsteocytes – mature bone cells

SpongySpongy Trabeculae – columns of bone with spaces Trabeculae – columns of bone with spaces

filled with red bone marrowfilled with red bone marrow

Micrograph of Spongy Micrograph of Spongy BoneBone

An electron micrograph scan of spongy bone in an osteoporosis patient. Osteoporosis occurs when a body's blood calcium level is low and calcium from bones is dissolved into the blood to maintain a proper balance.

Blood TissueBlood Tissue

Connective Tissue with a liquid matrixConnective Tissue with a liquid matrix Red Blood Cells (erythrocytes) – Red Blood Cells (erythrocytes) –

transport oxygentransport oxygen White Blood Cells – function in immunityWhite Blood Cells – function in immunity

Neutrophils, Eosinophils, Basophils, T and B Neutrophils, Eosinophils, Basophils, T and B leukocytes, natural killer cells and leukocytes, natural killer cells and MonocytesMonocytes

Platelets – participate in blood clottingPlatelets – participate in blood clotting