Introduction to Sports Science. Epithelial Tissue Epithelial Tissue: or epithelium is the lining,...

Introduction to Sports Introduction to Sports ScienceScience

Epithelial TissueEpithelial Tissue

Epithelial TissueEpithelial Tissue: or epithelium is the lining, : or epithelium is the lining, covering, and glandular tissue of the body. covering, and glandular tissue of the body.

Glandular epithelium forms various glands in Glandular epithelium forms various glands in the body.the body.

Covering and lining epithelium covers all free Covering and lining epithelium covers all free body surfaces.body surfaces.

FunctionFunction

Protection (protects against bacterial and Protection (protects against bacterial and chemical damage; cilia lining the respiratory chemical damage; cilia lining the respiratory tract)tract)

absorption (lines some digestive system organs absorption (lines some digestive system organs such as stomach and small intestine)such as stomach and small intestine)

filtration (kidneys absorb and filter)filtration (kidneys absorb and filter)

secretion (produces such substances as secretion (produces such substances as perspiration, oil, digestive enzymes, and mucus)perspiration, oil, digestive enzymes, and mucus)

Special characteristicsSpecial characteristicsEpithelial cells fit closely together to form Epithelial cells fit closely together to form continuous sheets. continuous sheets.

Membranes always have one free (unattached) Membranes always have one free (unattached) surface or edge. surface or edge.

The lower surface of an epithelium rests on a The lower surface of an epithelium rests on a basement membranebasement membrane, a structureless , a structureless material secreted by the cell.material secreted by the cell.

no blood supply of their own (avascular) no blood supply of their own (avascular) depend on diffusion from capillariesdepend on diffusion from capillaries

well-nourished- ability to regenerate well-nourished- ability to regenerate themselves.themselves.

ClassificationClassification

Each epithelium is given two names. Each epithelium is given two names.

The first indicates the relative number of cell The first indicates the relative number of cell layers it has. layers it has.

Simple epithelium (one layer of cells)Simple epithelium (one layer of cells)

stratified epithelium (more than one cell layer).stratified epithelium (more than one cell layer).

ClassificationClassification

The second describes the shape:The second describes the shape:

squamous cells- flattened like fish scales squamous cells- flattened like fish scales (squam = scale) (squam = scale)

cuboidal cells- are cube-shaped like dicecuboidal cells- are cube-shaped like dice

columnar cells- shaped like columnscolumnar cells- shaped like columns

Simple squamousSimple squamous

Simple squamousSimple squamous

Simple cuboidalSimple cuboidal

Simple cuboidalSimple cuboidal

Simple columnarSimple columnar

Simple columnarSimple columnar

Pseudostratified Pseudostratified columnarcolumnar

Pseudostratified Pseudostratified columnarcolumnar

Stratified squamousStratified squamous

Stratified squamousStratified squamous

TransitionalTransitional

Connective TissuesConnective Tissues

Characteristics:Characteristics:

variations in blood supply- most well variations in blood supply- most well vascularizedvascularized..

exceptions- tendons and ligaments have poor exceptions- tendons and ligaments have poor blood supply, and cartilages are avascular. blood supply, and cartilages are avascular.

(This is why all of these structures heal more (This is why all of these structures heal more slowly when injured). slowly when injured).

Extracellular matrix: Connective tissues are Extracellular matrix: Connective tissues are made up of many different types of cells plus made up of many different types of cells plus nonliving substance found outside of the cells. nonliving substance found outside of the cells.

Extracellular MatrixExtracellular Matrix

Makes connective tissues so different!Makes connective tissues so different!

Matrix is produced by the connective tissue Matrix is produced by the connective tissue cells and secreted to their exterior. cells and secreted to their exterior.

Depending on the connective tissue type, the Depending on the connective tissue type, the matrix may be liquid, semisolid or gel-like, or matrix may be liquid, semisolid or gel-like, or very hard.very hard.

able to bear weight, withstand stretching, or able to bear weight, withstand stretching, or even abrasion. even abrasion.

Various types and amounts of fibers are Various types and amounts of fibers are deposited in and form a part of the matrix deposited in and form a part of the matrix material. material.

They include: They include:

Collagen (white) fibersCollagen (white) fibers

Elastic (yellow) fibersElastic (yellow) fibers

Reticular (fine collagen) fibers.Reticular (fine collagen) fibers.

Fibers made by the connective tissue and Fibers made by the connective tissue and secreted.secreted.

(All connective tissues consist of living cells (All connective tissues consist of living cells surrounded by a matrix) surrounded by a matrix)

Differences reflect fiber type and number of Differences reflect fiber type and number of fibers in the matrix.fibers in the matrix.

Types of Connective Types of Connective TissuesTissues

From most rigid to From most rigid to softestsoftest

BONEBONE

CARTILAGECARTILAGE

DENSE CONNECTIVE TISSUEDENSE CONNECTIVE TISSUE

LOOSE CONNECTIVE TISSUELOOSE CONNECTIVE TISSUE

BLOODBLOOD

BONEBONEcomposed of bone cells composed of bone cells sitting in cavities called sitting in cavities called lacunae (lah-ku’ ne) and lacunae (lah-ku’ ne) and surrounded by layers of a surrounded by layers of a very hard matrix.very hard matrix.

The matrix contains The matrix contains calcium salts in addition to calcium salts in addition to larger numbers of collagen larger numbers of collagen fibers. fibers.

Ability to protect and Ability to protect and support other body organs.support other body organs.

Skull protects the brain. Skull protects the brain.

CARTILAGECARTILAGELess hard and more Less hard and more flexible than bone. flexible than bone.

Found in a few places in Found in a few places in the body.the body.

In hyaline cartilage, In hyaline cartilage, which is found in the which is found in the voice box, attaches the voice box, attaches the ribs to the breastbone ribs to the breastbone and covers the ends of and covers the ends of bones where they form bones where they form joints.joints.

DENSE CONNECTIVE DENSE CONNECTIVE TISSUETISSUEHas collagen fibers as its Has collagen fibers as its

main matrix element.main matrix element.

fibroblast (fiber-forming fibroblast (fiber-forming cells) manufacture these cells) manufacture these fibers.fibers.

Form strong rope-like Form strong rope-like structures such as tendons structures such as tendons and ligaments.and ligaments.

also makes up lower layers also makes up lower layers of the skin (dermis), of the skin (dermis), arranged in sheets.arranged in sheets.

TendonsTendons

Attach skeletal Attach skeletal muscle to bones.muscle to bones.

LigamentsLigaments

connect bones to connect bones to bones at joints.bones at joints.

more stretchymore stretchy

contain more contain more elastic fibers than elastic fibers than tendons.tendons.

LOOSE CONNECTIVE LOOSE CONNECTIVE TISSUETISSUE

Softer and have Softer and have more cellsmore cells

fewer fibers than fewer fibers than any other any other connective tissue connective tissue type except blood.type except blood.

3 Subclasses of LCT3 Subclasses of LCT

1.) Areolar tissue1.) Areolar tissue

soft, cushions and soft, cushions and protects body protects body organs it wrap. organs it wrap.

packing tissue packing tissue and connective and connective “glue”. “glue”.

2. Adipose Tissue:2. Adipose Tissue:

Common name- FAT.Common name- FAT.

insulates the body and insulates the body and protects it from extremes of protects it from extremes of both heat and cold. both heat and cold. (subcutaneous tissue (subcutaneous tissue beneath the skin)beneath the skin)

protects some individual protects some individual organs- kidneys surrounded organs- kidneys surrounded by capsules of fat, and by capsules of fat, and cushions the eye sockets. cushions the eye sockets.

fat “deposits” - such as fat “deposits” - such as hips and breast, where fat hips and breast, where fat is stored and available for is stored and available for fuel if needed. fuel if needed.

3. Reticular Connective 3. Reticular Connective tissue: tissue:

consists of a delicate consists of a delicate network of interwoven network of interwoven reticular fibers associated reticular fibers associated with reticular cells, which with reticular cells, which resemble fibroblasts. resemble fibroblasts.

Forms the stroma or Forms the stroma or internal supporting internal supporting framework. framework.

supports free blood cells- supports free blood cells- such as in the lymph such as in the lymph nodes, the spleen, and nodes, the spleen, and bone marrow.bone marrow.

Vascular tissueVascular tissue

consists of blood cells, consists of blood cells, surrounding by nonliving, fluid surrounding by nonliving, fluid matrix called blood plasma. matrix called blood plasma.

““fibers” are soluble protein fibers” are soluble protein molecules molecules

visible only during blood clottingvisible only during blood clotting

transport vehicle for the transport vehicle for the cardiovascular system:cardiovascular system:

carries nutrients, wastes, carries nutrients, wastes, respiratory gases, and other respiratory gases, and other substances throughout the body. substances throughout the body.

BLOODBLOOD

Muscle TissueMuscle Tissue

highly specialized highly specialized to contract or to contract or shorten, to produce shorten, to produce movement.movement.

Muscle fibers: Muscle fibers: muscle cells are muscle cells are elongated to elongated to provide a long axis provide a long axis for contraction. for contraction.

3 types of muscle tissue3 types of muscle tissue

Skeletal Muscle: Skeletal Muscle: voluntarily voluntarily

Cardiac Muscle: Cardiac Muscle: involuntary controlinvoluntary control

Smooth: involuntarySmooth: involuntary

Skeletal MuscleSkeletal Muscle: : controlled voluntarily controlled voluntarily ( or consciously). ( or consciously).

contractions pull on contractions pull on bones or skin.bones or skin.

results of action is gross results of action is gross body movement or body movement or change in our facial change in our facial expression. expression.

cells are long, cells are long, cylindrical, and cylindrical, and multinucleate; they are multinucleate; they are obvious striations obvious striations (stripes). (stripes).

Cardiac MuscleCardiac Muscle: : involuntary controlinvoluntary control

found only in the HEARTfound only in the HEART

striations, but uninucleate, striations, but uninucleate, branching cells that fit branching cells that fit tightly together (like tightly together (like clasped fingers) at clasped fingers) at junctions called junctions called intercalate intercalate disksdisks. .

Ions can pass freely from Ions can pass freely from cell to cellcell to cell

Smooth MuscleSmooth Muscle: : involuntaryinvoluntary

No striations are visible. No striations are visible.

individual cells have a individual cells have a single nucleus and are single nucleus and are spindle-shaped (pointed at spindle-shaped (pointed at each end). each end).

in walls of hollow organs- in walls of hollow organs- stomach, bladder, uterus, stomach, bladder, uterus, and blood vessels. and blood vessels.

wavelike motion that keeps wavelike motion that keeps food moving through the food moving through the small intestine.small intestine.